Cloud Base Calculator

Estimate convective cloud base (LCL) from surface temperature and dew point. Standard aviation rule of thumb for VFR planning.

Cloud Base Estimate

Estimates the lifting condensation level (LCL) — where rising air becomes saturated and forms convective clouds. Uses the standard aviation rule of thumb.

Units

Temperature (°F)

Dew point (°F)

Field elevation (ft MSL, optional)

Disclaimer

This is an approximation for convective/cumulus cloud bases only. Actual bases can vary due to inversions, moisture changes aloft, and local conditions.

Always check METAR/TAF and official forecasts. Not a substitute for official weather briefings.