1. What is the Lightning Distance Calculation?

The lightning distance calculation estimates how far away a lightning strike occurred based on the time difference between seeing the lightning and hearing the thunder. This works because light travels much faster than sound.

2. How Does the Calculator Work?

The calculator uses the lightning distance equation:

Where:

• \( time\_s \) — Time between lightning and thunder in seconds
• 343 — Speed of sound in meters per second (at 20°C)
• 1000 — Conversion factor from meters to kilometers

Explanation: For every second between the lightning and thunder, the storm is approximately 0.343 km away.

3. Importance of Lightning Distance Calculation

Details: Knowing how far away lightning is helps assess storm danger. If the time between lightning and thunder is decreasing, the storm is approaching.

4. Using the Calculator

Tips: Count the seconds between seeing lightning and hearing thunder, then enter that number. For best accuracy, use the first lightning/thunder pair you notice.

5. Frequently Asked Questions (FAQ)

Q1: Why use 343 m/s for sound speed?
A: This is the speed of sound at 20°C (68°F). Sound travels faster in warmer air and slower in colder air.

Q2: How accurate is this method?
A: It's reasonably accurate for distances under 20 km. Beyond that, atmospheric conditions and terrain can affect sound propagation.

Q3: What if I see lightning but don't hear thunder?
A: The storm may be more than 25 km away, or atmospheric conditions may prevent the sound from reaching you.

Q4: Is there a rule of thumb for estimating distance?
A: Divide the seconds by 3 to get approximate distance in kilometers (or divide by 5 for miles).

Q5: When should I seek shelter from lightning?
A: When lightning is within 10 km (about 30 seconds between flash and thunder).