WeatherMath: Wind Chill

WeatherMath computes the four weather numbers that need a formula rather than a forecast: wind chill, heat index, dew point and density altitude. You type the readings you already have, and the result updates as you type. Every calculation runs on your device, so it works with no signal, no station feed and no account. WHAT YOU CAN DO - Calculate wind chill from air temperature and wind speed in km/h, using the National Weather Service formula. - Calculate the heat index from temperature and relative humidity with the Rothfusz regression, the standard hot weather feels like value. - Calculate the dew point from temperature and relative humidity with the Magnus-Tetens approximation. - Calculate density altitude from field elevation in feet, altimeter setting in inHg and outside air temperature. - Switch between the four calculators in one tap; the temperature you typed carries across all four. - Read every result to one decimal, and density altitude to the nearest foot. - Type a decimal with either a comma or a period. - Open the About screen to see which formula produced each number. - Work in the dark or light appearance your phone is already set to. WHO IT IS FOR Pilots and paraglider pilots checking density altitude before takeoff. Crews and supervisors who have to call a wind chill number on a winter site. Coaches and event staff judging heat and humidity before a session. And anyone who wants to know what -10 °C actually feels like in a 30 km/h wind. RANGES THE FORMULAS COVER Wind chill applies at 10 °C or colder with wind of 4.8 km/h or more. The heat index applies from about 27 °C up. Outside those ranges the app shows the plain air temperature instead of a figure the formula cannot support. Density altitude is built from pressure altitude, then corrected by 120 feet for every degree Celsius the air sits above the standard atmosphere temperature. PRIVACY WeatherMath makes no network requests. There is no location permission, no station lookup, no sign in, no analytics and no ads. Nothing you type leaves the phone. WeatherMath is a calculator. It does not connect to any weather service or aviation authority, and its output is a reference figure, not a briefing or a warning.