Heavy rainfall from scattered thunderstorms is expected across the Southwest, Intermountain West, and Plains. Isolated dry thunderstorms may initiate additional fires across the west. The coastal Carolinas may experience flash floods in the coming days due to repeated thunderstorms. Additionally, a wave of intense summer heat will hit the Southern Plains and central Gulf Coast States this week. Read More >
The WetBulb Globe Temperature (WBGT) is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation). This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas. If you work or exercise in direct sunlight, this is a good element to monitor. Military agencies, OSHA and many nations use the WBGT as a guide to managing workload in direct sunlight.
|
|
![]() |
![]() |
WetBulb Globe Temperature | Heat Index |
Comparison with Heat Index
|
Examples
|
Preparedness - What to do before doing outdoor activities when the WBGT is high -
|
Other Resources
|
More WBGT Information WBGT Research Paper OSHA work load and WBGT Manual |
Suggested Actions and Impact Prevention | ||
WBGT(F)
|
Effects
|
Precautionary Actions
|
< 80 | ||
80-85 | Working or exercising in direct sunlight will stress your body after 45 minutes. | Take at least 15 minutes of breaks each hour if working or exercising in direct sunlight |
85-88 | Working or exercising in direct sunlight will stress your body after 30 minutes. | Take at least 30 minutes of breaks each hour if working or exercising in direct sunlight |
88-90 | Working or exercising in direct sunlight will stress your body after 20 minutes. | Take at least 40 minutes of breaks each hour if working or exercising in direct sunlight |
>90 | Working or exercising in direct sunlight will stress your body after 15 minutes. | Take at least 45 minutes of breaks each hour if working or exercising in direct sunlight |