Planning guidance, not a guarantee. Conditions can vary within a forecast area. Follow current official instructions and use local judgment for your route, equipment, health, and surroundings.
Compare a cooler start with your finish
Check the temperature trend through the end of the run. During extreme heat, the National Weather Service advises reducing or rescheduling strenuous activity for a cooler part of the day. A good start does not guarantee a comfortable finish.
An easy run and a hard workout are different
The planner uses a standard running profile; it does not know your pace or acclimatization. Compare a shorter run when the original duration does not fit, and read the pollutant-specific guidance when air quality is a concern.
Put the plan into the forecast
Start with the 45-minute default, then adjust it to your actual outing. Check official alerts and the reasons beside the recommended window before leaving.
Exertion makes heat and degraded air more consequential, while pace, fitness, acclimatization, and route remain personal unknowns.
Primary sources
These are the authoritative references behind this guide’s planning context.
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