FAQ
What is WBGT?
Wet-bulb globe temperature combines air temperature, humidity, wind and sunshine into one heat-stress number. NIOSH and the military use it to set work limits.
Where does the forecast come from?
The National Weather Service API (api.weather.gov), for the forecast grid cell that covers your address.
Why does my plan say 'estimated'?
Some NWS offices don't publish a WBGT forecast. For those grids, we estimate WBGT from temperature and humidity (Australian Bureau of Meteorology shade formula) and label it. It can read low in full sun.
Is this OSHA compliance?
No. It's planning guidance based on NIOSH's published limits. Your employer's heat illness prevention program and any state rules still apply.
What does 'Stop non-essential work' mean?
The forecast WBGT is above the NIOSH limit even for a resting worker. Postpone work if you can. If work must happen, it needs heat-stress controls and monitoring.
What are the workload levels?
ISO 7243 metabolic classes: light 180 W, moderate 300 W, heavy 415 W, very heavy 520 W.
Do you store my address?
No. Addresses are sent to the geocoder and NWS to build the plan. We don't keep them, and we don't use tracking cookies.
Does it work outside the US?
No. It covers US locations served by the National Weather Service.