Wolfram|Alpha has weather calculators. Solve problems related to the Air Quality Health Index (Canada), air quality indexes, average raindrop diameters, the barometric equation for US Standard Atmosphere, the barometric pressure at extreme geographic elevation, cloud base heights, cloud base heights based on location, degree days, density altitude calculations, the dew point temperature of air, heat indexes, the hypsometric equation, lightning distance, raindrop properties, the relative humidity of air, wind chill temperatures, the Ångström–Page equation, atmospheric pressure in the troposphere and rainbow altitude.
