Guide
Hiking in Tucson heat
This is not medical advice, and it can't speak to your own health or limits. Here are the official heat pages, and how the trail ratings handle heat.
Official pages
- NWS heat safety
- NWS Tucson forecast office
- Coronado front-range guide (March 2025), which says heat can be deadly and lists signs to watch for.
How the trail ratings work
Each trail rating goes by the hourly NWS temperature or the feels-like temperature, whichever is higher, plus any active alerts. The temperature bands are on the methods page. Every rating shows a forecast temperature and when the forecast was updated. If the forecast is missing or more than 6 hours old, or alerts couldn't be checked, the trail shows No rating.
The ratings don't account for shade, your fitness, how much water you carry, or how long the trail is. Several trailheads have no drinking water, so bring plenty of your own, and read the trail page before you go.
If an Extreme Heat Warning, Extreme Heat Watch, or Heat Advisory is in effect, the rating names it. During a Flash Flood Warning, Severe Thunderstorm Warning, or Dust Storm Warning, trails show No rating. Winter and cold alerts are named on every trail they cover. On the high-elevation trails (Aspen, Marshall Gulch, and Butterfly), a Winter Storm Warning, Blizzard Warning, Ice Storm Warning, or Extreme Cold Warning also means No rating.