Climatology Tools

Browse all available climatology tools.

Available tools

Accumulated Freezing Degree Days Calculator ObservedzeroC freezing indexdegree-daysmean-threshold,not max/mindaycomputationsor Stefanice-growth forecast. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Albedo Forcing Delta Temperature Apply caller area-weighted albedo perturbation to incident solar absorption and supplied equilibrium response; local/global incident-energy conventions must match and no climate feedbacks are inferred.
Angstrom-Prescott A-B Coefficient Solver Fit measured Angstrom–Prescott sunshine/solar fraction coefficients and predict supplied sunshine fraction, exposing calibration-range extrapolation; no universal local coefficients or sunshine forecast.
Annual Temperature Range Extractor Actualcomplete12-monthmeanmax-minannualrange,not annualabsoluteweatherextremes. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Anomaly Departure from Normal Calculator Signedactualdeparturefromindependently matchedbaseline,not standardizedz-score/referenceforecast. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Bioclimatic Variable BIO1-BIO19 Selector Compute BIO1–BIO19 under explicit equal-month weighting/population-SD and cyclic three-month quarters, retaining first tied quarter indices; monthly climate normals only, no raster/geographic selector or WorldClim hidden +1 precipitation convention.
Biologically Effective Degree Days Evaluate caller explicit BEDD thermal-cap, diurnal-range adjustment and daylight convention, exposing all calibration rather than prescribing a universal viticultural formula or maturity date.
Brunt-Vaisala Frequency Estimate layer N² from measured virtual potential temperature and report stable oscillation versus unstable growth separately; signed N² is preserved rather than attempting an imaginary frequency or claiming turbulence forecast.
Chill Hours Accumulator 0-7.2C Declaredinclusive0…7.2Cchill-hourbinaccumulationactualuniformtimeobservations,not DynamicModelchillportionsor dormancyforecast. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Clear Sky Transmissivity Estimate Estimate observed clear-sky bulk transmissivity from paired integrated surface/extraterrestrial energies; observations must be independently identified clear-sky, not assumed clear from station elevation.
Climate Normal 30-Year Averager Audit twelve month-of-year normals within an explicit 30-year baseline with independent observation flags/coverage, not missing-as-zero or a falsely complete climatological normal.
Climate Sensitivity Feedback Parameter Calculator Subtract signed amplifying feedback components from an independently specified positive Planck restoring response, then compute 1/net sensitivity. Requires stable positive net restoring feedback. Components are not inferred from warming; this is not a validated climate forecast.
Climate Zone Shift Velocity Solve minimum-norm isotherm velocity from caller temporal tendency and planar measured temperature gradient; sign follows dT/dt+v·gradT=0, not mapped migration, species movement or a geodesy operation.
CO2 Doubling Warming Estimate via Sensitivity Calculator Independently verified doubling forcing/net positive restoring feedback equilibrium warming—not log CO2 forcing calculation or transient response. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Cold Spell Duration Index CSDI Calculate cold CSDI minimum-temperature spells against caller independently calibrated day-of-year percentiles with strict exceedance and minimum run; threshold ties excluded, gap-free coverage required.
Consecutive Dry Days Counter Find complete dry runs in a caller gap-free observed daily sequence using strict precipitation below supplied threshold; endpoints may be truncated by observation coverage, not proven climate-season boundaries.
Continentality Gorczynski Index Evaluate named Gorczynski annual thermal-range continentality, retaining signed index and rejecting equatorial singularity; no geography or universal climate category.
Daylight Duration Latitude Calculator Geometriccenter-of-Sunzeroaltitudedaylengthfromactualindependentdeclination,polarflagsretained,no refraction/ephemeris/cloudsunshine. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
De Martonne Aridity Index Compute annual De Martonne P/(T+10) from twelve monthly normals, with explicitly positive shifted temperature; not a calibrated drought category or validity at cold singular temperatures.
Declination Angle Day-of-Year Evaluate named approximate FAO ordinal-day solar declination, not NOAA date/location sunrise calculation, sidereal astrometry or a geodesy operation.
Design Freezing Index Selection Lookup Independently verified site/baseline/return period design freezing index reference, not fixed regional building code or current soil state. Exact independently documented reference matching, signed discrepancy retained. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Dewpoint from RH and T Magnus Calculator Magnusliquidwaterdewpoint17.625/243.04,T−40…50C,0<RH≤1,no arbitrarydry0log/inferred saturationphase. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Diurnal Temperature Range Averager Actualmatchingdailymax−minarithmeticmean,not pairedmonthlyextreme subtraction. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Dry Adiabatic Height Change Track signed dry parcel temperature changes through an explicit unsaturated displacement path with supplied g/cp; unlike measured environmental lapse, no condensation or ground-clearance/safe-flight inference.
Effective Radiating Temperature Invert a spherical mean absorbed-solar equilibrium to effective radiating temperature with caller emissivity/Stefan constant; not actual surface temperature or existing forward thermal-flux calculation.
Extraterrestrial Radiation Daily Integrate geometric daily extraterrestrial solar radiation from independently supplied declination/distance correction, handling polar day/night without apparent sunrise/refraction or cloud attenuation.
Firbas Humidity Factor Calculator Independently verified Firbas method definition/temperature unit/precipitation period/regional reference, not invented universal humidity formula. Exact independently verified context/edition key; not embedded or live reference data. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
First Fall Frost Date Finder Locate first fall observed frost within caller seasonal window; -1 explicitly means no observed event and is not a validated frost-free date, calendar/hemisphere determined by caller.
Frost Days FD0 Counter Observed ETCCDIfrostdaysTN<0Cstrictendpoints/gapfreecompleteperiodexternallyverified,no missing-dayimputation. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Frost-Free Period Length Find longest observed contiguous frost-free daily period with explicit endpoint censoring; unlike one seasonal frost date, longest available span is not extrapolated outside coverage.
Geostrophic Wind Speed Compute signed east/north geostrophic vector under caller horizontal pressure gradients, density and Coriolis, not true terrain wind or a pressure-force magnitude alias.
Greenhouse Effect Enhancement Delta Compare actual supplied surface temperature against measured outgoing-longwave blackbody-equivalent emission temperature; unlike solar equilibrium temperature, no absorbed/OLR equality or causal greenhouse attribution is assumed.
Growing Degree Days Single Sinusoid Method Integrate ideal single-sinusoid daily temperature excess between caller lower and horizontal upper cutoffs analytically; differs from arithmetic daily-mean GDD and is not a development-event forecast.
Growing Season Length GSL Locate thermal growing-season onset/end under caller threshold/run and hemisphere-specific cold-end search index; preserve left-censored onset and right-censored end, without assigning dates outside supplied gap-free coverage.
Hardiness Zone Shift Steps Calculator Signedhardinesszone-stepchangeactualextrememinimumcontrast/independentlyappropriatezone-width°C,not officialzoneclassificationor plantviability. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Heat Index Climatological Exceedance Counter Count exposure above caller heat-index threshold using explicitly domain-restricted Rothfusz base regression, not the existing Steadman apparent-temperature tool; no low-RH adjustment or heat-health/work safety certification.
Holdridge Life Zone Classifier Holdridge biotemperature monthly 0 outside 0<T<30°C, PET=58.93 Tb; query caller independently verified life zone polygons in log 2 Tb/log 2 Pspace, not fake universal zone table. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Huglin Heliothermal Index Calculate Huglin mean/maximum heliothermal contributions over caller supplied season with caller latitude/daylength coefficient and base; no implicit hemisphere calendar or grape suitability classification.
Humidex Monthly Statistics Summarize measured vapor-pressure/temperature humidex across actual represented monthly exposure; no RH/dewpoint saturation reconstruction or health recommendation.
Ice Days ID0 Counter Observed ETCCDIIcedaysTX<0Cstrictendpoints/gapfreecompleteperiodexternallyverified,no missing-dayimputation. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Isothermality Percent Calculator BIO3isothermality100BIO2/BIO7matchedcompleteclimatologyperiods,not directspeciesclimateenvelope. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Koppen Climate Class Classifier Köppen–Geiger classification of twelve homogeneous monthly normals with the 0°C temperate/continental boundary and aridity tested first. Northern summer is April–September, reversed in the south. If both dry-season rules apply, s takes priority; tropical dry-season ties use the first driest month. Not a mapped climate identity, crop recommendation or forecast.
Koppen Subclass Letter Resolver Parse valid Köppen subclass letters by group syntax, does not derive climate from missing monthly data. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Lang Rain Factor Calculator Lang annual P/T rain factor with strictly positive annual mean temperature in Celsius. Distinct from De Martonne P/(T+10) and P/PET. Caller verifies normal coverage and applicability; not a drought category or crop suitability assessment.
Lapse Rate Environmental Fit measured environmental temperature profile and expose extrapolated-height predictions, retaining inversion sign; not a prescribed constant atmosphere or pressure/altitude conversion.
Last Spring Frost Date Finder Locate last spring observed frost within caller seasonal window; -1 explicitly means no observed event and is not a validated frost-free date, calendar/hemisphere determined by caller.
Lifting Condensation Level Height Compute named Bolton LCL temperature then caller dry-adiabatic pressure/height for a surface parcel; not existing dewpoint-spread fog proxy, inferred environmental cloud base or moist-convective ascent.
Linear Trend Slope per Decade Calculator OLS actual irregular year climate trend, distinct from Sen median pair slopes; no autocorrelation adjusted interval or forecast. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Mann-Kendall Monotonic Trend Test Compute ordered Mann–Kendall S, tie-corrected independent-observation null variance and continuity-corrected z; no serial-correlation adjustment or significance claim, at most one million pairs.
Max 1-Day Precipitation RX1day Extractor Extract observed RX1day with all tied ordinal indices and first maximum, without inventing a date for an incomplete series.
Max 5-Day Precipitation RX5day Extractor Extract RX5day from all complete overlapping five-day windows in a gap-free sequence, permitting cross-month windows supplied by caller; not monthly totals or partial-window extrapolation.
Oceanity Conrad Index Report named Conrad range/latitude-offset continentality and explicit 100-minus complementary oceanity convention; not clamped percentages or an independently validated maritime-climate probability.
Palmer Drought Severity Index Simplified Calculator Explicit classic linear Palmer recurrence X=p Xprevious+Z/3 with independently calibrated Z; not complete PDSI spell-selection/soil calibration or absolute drought severity from precipitation. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Permafrost Active Layer Stefan Solution Calculator Ideal soil Stefan sharp-front thaw depth using independently verified volumetric latent heat and SURFACE thaw index; no snow/groundn-factor inferred, not lake ice growth or real active-layer forecast. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Planck Response Parameter Calculator Derivative of ideal emissiveεσT⁴flux positive outgoing/restoring convention, not actual global Planck feedback spatial weighting. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Potential Temperature Poisson Compute pressure-normalized dry potential-temperature sounding under caller R/cp/reference pressure; no moisture normalization or actual measured parcel temperature at reference pressure.
Precipitation Seasonality CV Report measured twelve-month precipitation seasonality under population monthly SD, not sample SD or silently smoothed/+1 precipitation; zero mean leaves CV undefined.
Pressure Gradient Force per Mass Convert measured three-dimensional Cartesian pressure gradient to signed per-mass acceleration; no Coriolis balance, coordinates or hydrostatic-gravity cancellation inferred.
R95p Heavy Precipitation Fraction Compute R95p share on strict exceedance of a caller independently established baseline wet-day 95th percentile; ties are not exceedances and the analysis period is not silently its own baseline.
Radiative Forcing CO2 Logarithm Calculate signed logarithmic CO2 radiative forcing change using caller concentration convention/coefficient; no warming, verified forcing or neglected gas/aerosol response is inferred.
Rainy Days Threshold Counter Audit a supplied increasing rain-threshold policy over observed daily precipitation with coverage denominator; no missing-as-dry treatment or climate category lookup.
Recharge Estimate from Precipitation Fraction Calculator Conditionalprecipitation×independentlycalibratedrechargefraction,no actualgroundwaterrechargeguaranteeor soilprocessmodel. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Record High Margin Over Previous Compare new observed high with all previous eligible extrema, retaining signed margin and strict record equality semantics; exposure/record homogeneity must be caller established.
Record Low Margin Under Previous Compare new observed low with all previous eligible extrema, retaining signed margin and strict record equality semantics; exposure/record homogeneity must be caller established.
Reference Evapotranspiration Hargreaves Evaluate calibrated daily Hargreaves reference ET with explicit MJ/m²/day radiation converted to equivalent evaporation by 0.408; differs from Penman–Monteith weather inputs and is not actual crop ET.
Relative Strain Discomfort Index Calculator DeclaredThomDI=T−.55(1−RH/100)(T−14.5),empiricaldescriptor not medicaldiscomfortdiagnosis. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Runoff Coefficient Regional Estimate Lookup Pool observed runoff over matched rain-volume exposure. Ratios above one are preserved rather than clamped because stored water or other inflows may contribute. Requires independently matched catchment windows; not a fixed regional coefficient or forecast.
Saturation Vapor Pressure Tetens Calculator RestrictedliquidwaterTetenssaturationvaporpressurekPa,T−40…50C,no ice branchorfractionRHparameter. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Sen Slope Estimator Estimate Sen median of all pairwise slopes on actual irregular observation years; distinct from OLS regression and no independence-adjusted interval or extrapolation.
Simple Daily Intensity Index SDII Compute SDII using observed precipitation only on wet days at caller inclusive threshold; zero observed wet days is undefined rather than inventing a daily intensity.
Simple Energy Balance Model Equilibrium Temp Solver Solve bounded monotone nonlinear emissive-plus-linear-cooling energy balance with residual; extra cooling differs from blackbody solar equilibrium, assumptions are caller supplied and not a validated climate forecast.
Snow Density from SWE Calculator InverseobservedSWE/depthbulksnowdensity,no inferredsnowpackstratigraphy/avalanchesafety. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Snowfall to Liquid Ratio Calculator Actualnew-snow/liquidequivalentratio,not assumeuniversal10:1or depth-density profile. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Solar Constant Adjustment Eccentricity Factor Evaluate FAO seasonal inverse relative Earth–Sun distance squared correction on a caller valid ordinal day/year length; not true orbital elements or a sunlight/irradiance forecast.
Standard Deviation of Anomaly Z-Score Calculator ActualanomalyzscoreagainstINDEPENDENTbaseline moments,not automaticallynormalizeanalysissample. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Standardized Precipitation Evapotranspiration Index SPEI Calculator SPEI standard-normal transform of an independently season/aggregation-matched precipitation-minus-PET CDF calibration. Water balance may be signed; no automatic log-logistic fit or tail extrapolation. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Standardized Precipitation Index SPI Calculator SPI standard-normal transform of an independently season/aggregation-matched precipitation CDF calibration. Zero-mass treatment and baseline completeness are caller verified; no automatic gamma fit or tail extrapolation. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Summer Days SU25 Counter Observed ETCCDIsummerdaysTX>25Cstrictendpoints/gapfreecompleteperiodexternallyverified,no missing-dayimputation. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Temperature Seasonality SD x100 Calculator BIO4populationSDactual12monthlymeans×100°C convention,not sampleSDorcoefficientofvariation. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Thawing Index Accumulator Calculator ObservedzeroC thawing indexdegree-daysmean-threshold,not max/mindaycomputationsor Stefanice-growth forecast. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Thermohydrogram Ratio Classifier Explicit caller thermohydrogram Pvspositive Tax is ratio and month dryness screen—not Lang annual factor or biological water balance. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
Thornthwaite Moisture Index Calculate named Thornthwaite Ih-0.6 Ia from caller precomputed monthly soil-water surplus/deficit and PET; not precipitation-minus-PET substituted for a full soil water budget.
Thornthwaite PET Monthly Evaluate basic monthly Thornthwaite PET from twelve temperature/daylight/month-length normals with explicit heat index and high-temperature calibration-domain refusal; no measured ET or soil budget.
Transient Climate Response TCR Estimator Evaluate one-box transient response at end of a linear forcing ramp (exponential CO2 growth under logarithmic forcing), with explicit restoring feedback/heat capacity/time and stable short-ramp limit; not observed TCR.
Trewartha Climate Classifier Trewartha main thermal groups using the Patton dry threshold 10(2.3T−0.64Ps+41), with Ps the summer precipitation percentage. Requires twelve homogeneous monthly normals and explicit hemisphere. Does not implement subclasses, establish mapped climate identity or predict future climate.
Tropical Nights TR20 Counter Observed ETCCDItropicalnightsTN>20Cstrictendpoints/gapfreecompleteperiodexternallyverified,no missing-dayimputation. Actual independent units,calibration,measurement definitions/coverage and model applicability;not a climate forecast,causal determination,geodesy operation or safe travel/design approval.
Turc Irrigation Need Calculator Daily Turc reference ET with MJ→cal/cm²solar conversion and low RH correction; rain-only reference gap not crop irrigation prescription/soil budget. Caller independently establishes homogeneous observation coverage and model/reference applicability; not observed future climate, crop suitability or validated drought severity.
UNEP Aridity Index P over PET Compute annual UNEP P/PET from matched monthly normals and show seasonal nonnegative climate deficits; no fixed aridity classification or inference of actual crop water stress.
Virtual Temperature Correction Compute exact ideal moist-air virtual temperature with vapor and suspended-liquid specific mass fractions relative to total mixture; differs from vapor mixing-ratio approximations and excludes ice unless caller independently models it.
Warm Spell Duration Index WSDI Calculate warm WSDI maximum-temperature spells against caller independently calibrated day-of-year percentiles with strict exceedance and minimum run; threshold ties excluded, gap-free coverage required.
Water Balance Surplus Deficit Classifier Conserve sequential single-bucket soil water with precipitation, PET, actual evaporation, overflow surplus and unmet-demand deficit; no groundwater recharge/irrigation guarantee and all bucket processes are declared simplifications.
Wet Spell Length Analyzer Analyze full consecutive wet spell distribution at a caller inclusive precipitation threshold; supplied sequence must have no missing days and zero means no observed qualifying spell.
Wind Chill Climatological Monthly Mean Summarize caller observed month exposure using existing wind-chill equation only where T≤10 C and wind≥4.8 km/h; invalid observations are excluded with coverage, not computed from monthly mean weather or certified cold safety.
Winkler Index GDD Region Classifier Resolve an already supplied seasonal GDD into caller Winkler-region policy bands, using lower-inclusive boundaries; no duplicate GDD accumulation, mutable region constants or crop recommendation.

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