This app tracks humid-heat conditions using Wet Bulb Globe Temperature (WBGT) to help you plan outdoor activities safely. It provides alerts, hourly timelines, and guidance based on risk levels.
1.2.7
September 28, 2026
FORECAST ALERTS Evening Forecast Alert: a 7 PM notification when tomorrow's forecast includes high Wet Bulb temperatures. Unlock with WetBulb+. ALERTS THAT TRAVEL WITH YOU Travelling Widget and App Alerts: if you travel, heat alerts, the widget and your Apple Watch update to your current location, even while the app is closed. Unlock with WetBulb+. THE SAFETY LEVELS HAVE BEEN ADJUSTED The temperatures that set the five levels — 23, 26, 29, and 32°C (73, 79, 84, and 90°F) — and their names — Comfort, Mindful, Caution, Warning, and Critical — have been adjusted. Each level is based on a published heat-stress threshold used by occupational safety bodies, health ministries, and militaries; the 32°C / 90°F where Critical begins is the point at which outdoor training is suspended for young, fit military adults. Reference links are in the 'About Wet Bulb' sheet. ALERTS CUSTOMIZATION Alerts now arrive at Caution, Warning, and Critical. Because Caution is a common summer morning in many regions, Settings can switch off that first level and leave Warning and Critical on. WET BULB TEMPERATURE NOW LIVES IN THE CALCULATOR The Calc tab takes the current location's air pressure, sky conditions, and the sun's position from the current hour, to show a relevant Wet Bulb Temperature. It sits next to the Outdoor WBGT above it for comparison.
MoreThe Wet Bulb Temperature Tracker is a free application that monitors humid-heat conditions using Wet Bulb Globe Temperature (WBGT). It provides alerts and hourly timelines to help users plan outdoor activities safely.
The app calculates WBGT from air temperature, humidity, sun, and wind, following the US National Weather Service's forecast method. It uses a psychrometric solve for Wet Bulb and the Dimiceli and Piltz globe model.
'Feels Like' indicates how hot the air feels, while Wet Bulb Globe Temperature (WBGT) measures how effectively your body can cool through sweat evaporation. A high WBGT indicates a greater risk of overheating.
No, the Wet Bulb Temperature Tracker does not contain advertisements. It is a free application with optional in-app purchases for additional features.
The WetBulb+ upgrade, available as a yearly subscription or one-time purchase, offers six-day forecast timelines, an Apple Watch app, and two Home Screen widgets for convenient access to WBGT readings and timelines.
The Wet Bulb Temperature Tracker has an age rating of 4+, making it suitable for a wide range of users.
The Wet Bulb Temperature Tracker is supported on Apple Watch and iPhone devices.
The app was last updated on September 18, 2026, indicating active development and maintenance.
