Heat Index: Bulb

Heat Index answers one question: will I overheat? It shows the heat index and the WBGT where you are standing, hour by hour, and warns you before the day crosses your line. Every number is computed on your phone from Apple Weather data — temperature, humidity, wind, cloud cover and the sun's exact angle at your coordinates. No account, no ads, no analytics. Your location goes to Apple's WeatherKit and nowhere else. TWO NUMBERS, ONE TAP APART The National Weather Service says it plainly: for day-to-day activities the heat index serves you well; if you work outside in full sun, use the WBGT. Heat Index gives you both. A picker at the top chooses which one you are reading; the whole screen follows it. Both flag onto the same five names — Comfortable, Caution, Extreme caution, Danger, Extreme danger — each on its own published scale: the NWS chart steps for the heat index, the US military…