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 formula:

Where:

• \( d \) — Distance to lightning in kilometers
• \( t \) — Time delay 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 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 seconds between seeing lightning and hearing thunder, then enter that number. For accuracy, use the average of several time measurements.

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 results.

Q3: What if I see lightning but don't hear thunder?
A: The lightning is either very distant (beyond ~25 km) or the thunder is being blocked by terrain or wind direction.

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

Q5: When should I seek shelter from lightning?
A: When lightning is within 10 km (30 seconds between flash and thunder), you should be in a safe location.