Resources · Free tools
Free lightning and heat safety tools
Two calculators for the person who has to make the call on the field or the job site. Both are free, run in your browser and show their working, with the published method and sources beside the answer.
Try it · WBGT in full sun
At 50% humidity and a 5 mph wind
82.4 °F
GHSA band: 82.0–86.9 °F
Calculators
- Heat · WBGT
WBGT calculator
Estimate WBGT from temperature, humidity, wind and sun, with the method shown and the result placed in a state activity band.
Open the WBGT calculator - Lightning · Flash to bang
Lightning distance calculator
Turn a flash-to-thunder count into miles and kilometres, with a tap timer and what current guidance says at that distance.
Open the distance calculator