---
source: https://iinventedlight.com/library/notes/lightning-basics.md
title: "How lightning and thunder work"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; restated in our own words"
attribution: "Summary by iinventedlight (AI-assisted). Sources: NOAA NWS, Understanding Lightning Science, US government work, public domain; NOAA NSSL, Severe Weather 101: Lightning Basics, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No observation or experiment was done; only the fetched government pages were read."
category: coverage-gaps
topic_area: "science-explain: weather"
tags: science, weather, lightning, thunder, storms
sources:
  - id: S1
    title: "Understanding Lightning Science"
    publisher: NOAA NWS
    url: https://www.weather.gov/safety/lightning-science-overview
    accessed: 2026-11-04
    license: "US government work, public domain"
  - id: S2
    title: "Severe Weather 101: Lightning Basics"
    publisher: NOAA NSSL
    url: https://www.nssl.noaa.gov/education/svrwx101/lightning/
    accessed: 2026-11-04
    license: "US government work, public domain"
---
# How lightning and thunder work

## Short answer
Inside a thunderstorm, collisions between ice particles separate electric charge. Lightning is a giant spark between opposite charges, either inside the cloud or between the cloud and the ground. The spark heats the air to about 50,000 °F, and the air expands so fast it makes thunder. [S1][S2]

## Key points
- **Two main kinds:** intra-cloud lightning and cloud-to-ground lightning. [S1][S2]
- **Heat:** a lightning channel briefly heats the air to around 50,000 °F, hotter than the Sun's surface. [S1][S2]
- **How far away?** Sound travels about a mile every 5 seconds. Count the seconds from flash to thunder and divide by 5 for miles. [S1]
- **Safety:** if you can hear thunder, you are close enough to be struck; go to a safe place. [S1]

## Claims
- id: C1
  claim: Lightning occurs between opposite charges within a cloud or between cloud and ground.
  source: S2
  evidence: "Lightning can occur between opposite charges within the thunderstorm cloud"
- id: C2
  claim: Lightning can heat the air to 50,000 degrees Fahrenheit.
  source: S1
  evidence: "it can heat the air to 50,000 degrees Fahrenheit"
- id: C3
  claim: Thunder travels about a mile every 5 seconds.
  source: S1
  evidence: "The sound of thunder travels about a mile every 5 seconds."
- id: C4
  claim: Heating from the lightning channel makes the air explode outward, causing thunder.
  source: S2
  evidence: "This causes the air to explode outward."

## Sources
- [S1] Understanding Lightning Science. NOAA NWS. https://www.weather.gov/safety/lightning-science-overview . License: US government work, public domain. Accessed 2026-11-04.
- [S2] Severe Weather 101: Lightning Basics. NOAA NSSL. https://www.nssl.noaa.gov/education/svrwx101/lightning/ . License: US government work, public domain. Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).