Heat Compass vs Wet Bulb Temperature Tracker
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Heat Compass
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Heat Compass turns the official military heat-flag system into a personal heat-safety coach. It computes WBGT (wet bulb globe temperature), the standard used by the U.S. Marine Corps and occupational safety programs, from live weather for your location, then tells you plainly what the conditions mean and what to do about them. KNOW THE FLAG - Live WBGT and the five-color heat flag (White, Green, Yellow, Red, Black) for where you are right now - Work-rest guidance for each flag: how long to work, how long to cool down - 7-day forecast with heat flags, so you can plan the week - Nearby weather stations, and transparency about which station your reading came from STAY AHEAD OF DEHYDRATION - A daily water goal derived from the heat, your activity level, and optionally your body weight - One-tap drink logging with reminders that adapt to the heat flag - An "I'm outside" mode that tightens reminders while you are exposed - Track drinks for family members or a work crew with household tagging - Guidance is capped at safe intake rates, because drinking too much is also dangerous GET WARNED EARLY - Proactive heat-risk alerts: the app periodically checks conditions and warns you when the flag climbs, even when the app is closed - A pavement heat check that estimates surface temperature, useful for dog owners and hot-surface work PRIVATE BY DESIGN No account and no sign-in. Your hydration log, profile, and settings stay on your device. Your location is used to fetch weather for where you are and is not stored on our servers. No ads, no tracking, free. A NOTE ON SCOPE Heat Compass provides general heat-safety guidance based on published heat-stress doctrine. It is an aid for planning, not a medical device, and it does not replace occupational safety programs, OSHA requirements, or your own judgment.
Wet Bulb Temperature Tracker
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.
- Wet Bulb Globe Temperature (WBGT) calculation
- Humid-heat risk alerts
- Hourly temperature timeline
- Activity guidance by risk level
- Manual calculation tool
- Global city search
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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/
Screenshots
Verdict
The clearest difference is iOS requirement: Heat Compass at 16.0 against Wet Bulb Temperature Tracker's 18.0. On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Heat Compass ships an update weekly, Wet Bulb Temperature Tracker every 4 days. The most recent releases landed on October 7, 2026 and October 24, 2026 respectively.
| Parameter | Heat Compass | Wet Bulb Temperature Tracker |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (2 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 2 — better |
| Update frequency | Weekly | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone | iPhone, Apple Watch — better |
| Requires iOS | 16.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 44 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | craig merry | Sameer Rajadnya |
In-app purchases
Heat Compass
No in-app purchases
Wet Bulb Temperature Tracker
No in-app purchases
Questions
Is Heat Compass free?
Is Wet Bulb Temperature Tracker free?
Do Heat Compass or Wet Bulb Temperature Tracker have ads?
Which is updated more often, Heat Compass or Wet Bulb Temperature Tracker?
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