Heat stress in Seattle
Cool and temperate, but rare heat domes turn dangerous fast in a region where AC is uncommon.
Heat stress is low right now — normal outdoor activity is fine.
Live wet-bulb globe temperature via the Liljegren (2008) method · automatically refreshed about every 30 minutes.
View Seattle on the live mapReading heat stress in Seattle
Wet-bulb globe temperature (WBGT) is the heat measure that actually tracks danger to the body. Unlike the plain air temperature on your phone, it folds in humidity, wind, and direct sun — the factors that decide whether your sweat can still cool you. It’s the standard the military, athletic associations, and occupational-safety bodies use to call when outdoor activity is no longer safe.
That matters in Seattle because cool and temperate, but rare heat domes turn dangerous fast in a region where AC is uncommon. The number above is the live outdoor WBGT for the city right now; tap through to the live map to inspect any neighborhood, scrub the forecast hour by hour, and see the 7-day outlook.
Heat in Seattle: common questions
What is the WBGT in Seattle right now?
Right now it's about 55°F WBGT (safe heat stress). This page shows the live wet-bulb globe temperature for Seattle, Washington, refreshed automatically about every 30 minutes. Open the live map for an exact reading at your neighborhood and an hour-by-hour forecast.
Why is WBGT more useful than the temperature for Seattle?
Air temperature ignores humidity, wind, and sun — the things that decide whether heat is dangerous. Seattle's climate (cool and temperate, but rare heat domes turn dangerous fast in a region where AC is uncommon.) is exactly why a single "feels-like" or thermometer reading can understate the real risk. WBGT captures all of it in one number.
When is heat most dangerous in Seattle?
Heat stress typically peaks in the early-to-mid afternoon, when sun load is highest. Plan strenuous outdoor activity for early morning or evening, hydrate ahead of time, and use the forecast scrubber on the live map to find the safest window.
Is WetBulbTracker free to use for Seattle?
Yes. WetBulbTracker is free, needs no account, and works for anywhere on Earth — not just Seattle. You can install it to your home screen and even set heat alerts.