How long must we wait after the last thunder before resuming play?

Wait at least 30 minutes after the last thunder before going back outside. Each new rumble restarts the 30-minute count.

Environment and Climate Change Canada adds that most lightning injuries and deaths happen before rain starts or after it stops, so a dry field is not a sign it is safe.

To estimate distance, count the seconds from the flash to the thunder and divide by three to get kilometres (15 seconds is about 5 km). The 30-minute rule applies from the last thunder you hear.