About this app

High Wet Bulb Globe Temperature (WBGT) days are more common each year. This free Wet Bulb Tracker sends you alerts and keeps you informed. Plan your activities for the day, at work or with family, with your health and safety in mind. Air Temperature is about hot air. Wet Bulb Temperature measures humid-heat conditions to indicate how much your body can cool without help, when active outdoors. Our body runs at about 36°C / 97°F, so a Wet Bulb of 30°C / 86°F feels uncomfortably warm, and by 35°C / 95°F the body dangerously overheats. THE OUTDOOR READING, FRONT AND CENTRE Wet Bulb is usually read off instruments in the field, but mathematical models let us work it out from weather data for a location. Wet Bulb Globe Temperature (WBGT) is calculated in the app from air temperature, humidity, sun, and wind. Calculations follow the US National Weather Service's forecast method: a psychrometric solve for Wet Bulb, and the Dimiceli and Piltz globe model. This reading is useful when working, training, or walking outside, as a heat risk warning. WET BULB MATH ANSWERS A DIFFERENT QUESTION FROM 'FEELS LIKE' Feels Like answers: how hot does the air feel? A Feels Like of 32°C / 90°F is just a warm day. Wet Bulb Globe answers: how much can sweating cool you outdoors? A Wet Bulb Globe of 32°C / 90°F is Critical, and tells you to immediately stop exertion outside and stay actively cool. It matters. HEAT ALERTS Alerts notify you when outdoor Wet Bulb rises at your location. Adjust alerts in Settings. SEE A WHOLE DAY'S TIMELINE View an hourly timeline of each day's Wet Bulb Globe temperature, colored by safety level, showing how humid-heat builds and fades. Drag the marker across the day and the readings above it change. Hours likely to see rain show a smaller bar giving the percentage chance in your area. KNOW WHAT TO DO Every risk level comes with basic but handy Guidance: how long it's reasonable to stay out, what to watch for, and when to take breaks. The About page links to the Wet Bulb thresholds used by militaries, occupational safety bodies, and national weather services worldwide. WORK IT OUT - GET AN UNDERSTANDING The Calc tab lets you slide in any air temperature, humidity, wind speed, and solar radiation and watch both readings respond. Useful for teaching the concept or calculating from data. FREE WET BULB TRACKER: The Wet Bulb Globe reading wherever you are, today's full hourly timeline with chance of rain, 'Rising Wet Bulb' alerts, Heat care guidance, the calculator with both readings, and city search worldwide. UNLOCK WETBULB+ An optional upgrade, as a yearly subscription or a single one-time purchase: • Six-day forecast timelines, for picking safe days and times when planning activity • An Apple Watch app with the current reading, safety level, and the day's timeline • Two Home Screen widgets. Glance at the current reading, safety level, and timeline. • Apple Weather as your data source, for more precise local data Wet Bulb Tracker is an informational tool. It is not a substitute for official weather warnings, workplace safety guidance, or medical advice. The WetBulb+ subscription renews yearly unless canceled at least 24 hours before the period ends. Payment is charged to your Apple Account, and you can manage or cancel in your Apple Account settings. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://tulkitdesign.com/wetbulb-tracker-privacy-policy/