Weather for the Turf Industry
Heat stress is defined as a nighttime (8:00 pm through 8:00 am) hour when the sum of the temperature (°F) and Relative Humidity (%) exceeds 150. On a daily basis, high risk corresponds to eight or more heat stress hours. Low risk days have fewer than four heat stress hours. Moderate risk occurs otherwise. On the weekly maps, red dots generally indicate weeks with at least 2 high heat stress days or consistent (typically more than 4 days) moderate risk. Weeks with low risk have two or fewer moderate risk days. Moderate risk is indicated otherwise.
Forecast maps are based on National Weather Service forecast guidance.