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80 F + 75% Humidity, Endurance Sports

Audience: Endurance athletes, race directors
Air Temp
80°F
27°C
Humidity
75%
Heat Index
86°F
30°C
Risk band
Caution

What this means

Borderline for marathon and triathlon. USATF and Ironman policies pause or shorten races when the wet-bulb globe temperature passes 82 F.

What to do

Slow target pace by 30 seconds per mile. Pre-cool with an ice vest 15 minutes before start. Salt and carb drink every 20 minutes during race.

Source

ACSM Exertional Heat Illness Guide

Other Caution scenarios

Not medical advice. The NWS Steadman heat index is a general guideline; individual heat tolerance varies with acclimatization, medications, and pre-existing conditions. Consult a medical professional for individual risk assessment.