Use this sailing calculation for planning or education when the vessel, units, reference directions, environmental conditions, and assumptions are explicitly known.

Air temperature (°C)

Required number in °C. Dry bulb air temperature in degrees Celsius.

Wind speed (km/h)

Required number in km/h. Wind speed at ten metres above the surface.

The cited overview of Sailing supplies background for the terminology and domain context used by this tool.^[1]

Compute the wind chill apparent temperature from the standard joint environment committee formula for cold and windy conditions. Inputs are interpreted exactly in the displayed units and the calculation returns the following fields without presentation rounding.

Apparent temperature (°C)

Returned number in °C. Apparent temperature felt on exposed skin due to wind cooling.

• Vessel design and loading, sea state, wind, current, tide datum, weather, chart accuracy, equipment, crew, and safety margins can make real conditions differ from a simplified result.
• Use finite inputs in the displayed units, preserve source measurements and assumptions, and independently verify consequential decisions.

Cross-check current charts, tide and weather services, instrument data, vessel manuals, and applicable navigation rules, and retain a conservative alternative plan.

• Apparent Temperature Calculator

  Compute the simplified apparent temperature from air temperature, humidity-derived vapour pressure, and wind speed. With wind omitted, the result represents still air.

• Apparent Wind Angle Calculator

  Compute the apparent wind angle from true wind speed, boat speed, and true wind angle.

• Apparent Wind Speed Calculator

  Compute the apparent wind speed from true wind speed, boat speed, and true wind angle.