Thunderstorm distance

Thunderstorm distance helps you estimate how far a thunderstorm is by timing the interval between a lightning flash and the resulting thunder. Thunderstorm distance provides a simple flash-to-bang timer and an immediate distance calculation in kilometers or miles, and Thunderstorm distance can optionally keep a short history of recent readings for quick reference.

Features

This app includes a flash-to-bang timer with optional audible and visual cues, a distance calculation based on the speed of sound with a choice of kilometers or miles, and a manual entry mode for observed flash and thunder times. A compact history log lets you review recent estimates, and the app is lightweight and works offline without requiring an account.

How it works

The app measures the time between a visible lightning flash and the audible thunder, then converts that interval into an approximate distance. Results are approximate and intended to indicate proximity to storm cells; they should not replace official weather warnings or local emergency guidance. Core calculations do not require an internet connection.

Safety tips

Use the distance estimate as a general indicator only. Move indoors if thunder is nearby and follow local safety guidance. Do not rely solely on this app for life-or-death decisions; consult official alerts and forecasts.