The cloud base is the altitude at which rising, cooling air reaches saturation and condenses into the flat bottom of a cumulus cloud. Pilots, glider and paraglider enthusiasts, and weather watchers all care about it because it marks the ceiling of comfortable flight and the start of thermals. This calculator uses the classic Espy estimate, which says the convective cloud base sits roughly at the height where the spread between the surface temperature and the dew point closes at a rate of about 2.5 degrees Celsius per one thousand feet. Enter the surface air temperature and the dew point, choose Celsius or Fahrenheit, and read the estimated cloud base above ground level in both feet and meters. It is a rule of thumb for fair weather cumulus, not a substitute for a proper sounding. All computation runs locally in your browser for immediate, private results.
The cloud base is the altitude at which rising, cooling air reaches saturation and condenses into the flat bottom of a cumulus cloud. Pilots, glider and paraglider enthusiasts, and weather watchers all care about it because it marks the ceiling of comfortable flight and the start of thermals.
Yes. Cloud Base Height Calculator is completely free, with no sign-up and no usage limits.
Yes. Cloud Base Height Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Cloud Base Height Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.