Running in hot weather
When is the best time to run in the heat?
A heat wave turns "I'll run later" into a real planning question. The coolest hour is not always the best hour: dew point, wind, sun, air quality, and storms can change the answer.
Start with the whole window, not the temperature
A forecast temperature is one input, not a verdict. A useful running window is a stretch where the conditions stay manageable for the time you plan to be outside. Check the start, the middle, and the end of the run rather than choosing the first cool-looking hour.
Dew point changes how heat feels
Relative humidity can look high on a cool morning and lower later in the day. Dew point gives you a steadier view of how much moisture is in the air. When it is high, sweat has a harder time evaporating, so the same temperature can feel much more taxing.
Compare morning and evening honestly
Early morning can reduce direct sun and air temperature, but it may still be humid. Evening can have lower UV, but heat stored in roads and buildings, poor air quality, or thunderstorms can make it the worse choice. Compare all of those inputs together instead of assuming dawn always wins.
Shorten or move the run when the risk is clear
An official heat alert, poor air quality, a thunderstorm risk, or warning symptoms are reasons to change the plan. Move indoors, shorten the session, or choose another day. A weather score is a planning aid, not a reason to push through feeling unwell.
A simple heat-wave check
- 1. Check air temperature and dew point together.
- 2. Check UV, wind, rain timing, and air quality across the whole run.
- 3. If heat, pollution, or storms make the plan unsafe, move it or shorten it.
- 4. Use your symptoms and official local warnings as the final stop signal.
Keep planning
Check the next running window in GoWindow.
