Heat stress in Denver
Thin mile-high air means intense solar load: strong daytime heat stress despite low humidity.
Light precautions for intense activity. Keep water handy.
Wet-bulb globe temperature via the Liljegren (2008) method. This page is cached and refreshes in the background, so the live badge below can be a few minutes ahead of it.
View Denver on the live mapReading heat stress in Denver
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 Denver because thin mile-high air means intense solar load: strong daytime heat stress despite low humidity. 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.
How hot Denver usually gets
Across 2015–2024, Denver averaged a 86°F daily high in summer: 89th hottest of the 174 metros we track, and July is typically the warmest month.
Summer runs warm rather than extreme: about 36 days a year reach 90°F, and 100°F is essentially unheard of.
At about 47% summer humidity, the air is damp enough to blunt how well sweat cools you on the worst afternoons.
A bad day runs well past a normal one, with 101°F recorded against a 86°F summer average.
Daily high temperatures and humidity from ERA5 reanalysis, 2015–2024 (hottest day in the sample: 2018-06-28). These are climate averages for context: the reading at the top of this page is the live one.
For school sports, CHSAA (Colorado High School Activities Association) publishes CHSAA Sports Medicine Advisory Handbook: Heat Illness / Monitoring Environment, which uses wet-bulb globe temperature. Colorado’s activity zones appear beside the live reading in the app. Our Colorado heat policy page has the details, the source and the date we last checked it.
Heat in Denver: common questions
How hot does it usually get in Denver?
Across 2015–2024, Denver averaged a 86°F daily high through summer, with about 36 days a year at or above 90°F. July is typically the hottest month, and the hottest day in that sample reached 101°F. Figures are from ERA5 daily reanalysis.
When is the hottest time of year in Denver?
July has the highest average daily high in Denver. Summer humidity averages about 47%, enough to blunt how well sweat cools you on the hottest afternoons. Use the forecast on this page to plan around the specific days that matter.
Does Colorado have a heat policy for school sports?
CHSAA (Colorado High School Activities Association) publishes CHSAA Sports Medicine Advisory Handbook: Heat Illness / Monitoring Environment, which uses wet-bulb globe temperature. Colorado’s activity zones appear beside the live reading in the app. Our WBGT is a modeled estimate rather than the on-site device reading a policy may call for, so check the association's own document for current requirements.
What is the WBGT in Denver right now?
The reading at the top of this page is the current wet-bulb globe temperature for Denver, Colorado, computed from live weather by the Liljegren (2008) method and labeled with how recently it updated. For an exact reading at your own neighborhood, plus an hour-by-hour forecast, open the live map.
Why is WBGT more useful than the temperature for Denver?
Air temperature ignores humidity, wind, and sun: the things that decide whether heat is dangerous. Denver's climate (thin mile-high air means intense solar load: strong daytime heat stress despite low humidity.) 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 Denver?
July is the peak month in Denver, and within a day heat stress is highest in the early-to-mid afternoon when sun load is greatest. About 36 days a year reach 90°F, so most of the risk sits in a handful of afternoons rather than across the whole season. Use the forecast on this page to find the window that works.
Put Denver’s live heat stress on your site
A self-updating WBGT badge for schools, teams, camps, and local sites: it always shows the current reading and links back here.
<iframe src="https://wetbulbtracker.com/embed/denver-co" width="340" height="150" style="border:0" title="Live WBGT: Denver, CO" loading="lazy"></iframe>Paste it into any website. The badge updates itself and links back here. Add ?theme=light for light sites.