How loud is thunder?
Thunder typically reaches about 100 to 120 dB. The National Park Service measured thunder at 100 dBA in Arches National Park and says a crack of thunder can exceed 120 decibels, loud enough to cause pain; Purdue University's chart also lists a thunderclap at 120 dB.
- Level
- 100–120 dBA maxA-weighted maximum sound level
- Daily limit
- 9 s a dayNIOSH, at the loud end
- Versus conversation
- 56,234× energyabout 26.9× as loud
What the numbers mean
How it was measured. Thunder measured by the NPS in Arches National Park (100 dBA). The NPS also says a crack of thunder can exceed 120 decibels, and Purdue University lists a thunderclap at 120 dB; distance to the lightning strike not stated, and only the 100 dBA figure states A-weighting.
Thunder is the sound of air heated suddenly by a lightning bolt. How loud it is depends mostly on how close the strike is.
The National Park Service lists thunder at 100 dBA in its table of sound levels measured in parks (Arches National Park) and separately notes that the crack of thunder can exceed 120 decibels, loud enough to cause pain to the human ear. Purdue University's noise comparison chart puts a thunderclap in its 120 dB row, labelled 'painful'.
How long is safe?
NIOSH recommends no more than 9 s a day at 120 dBA (15 min at 100). OSHA's legal limit is 7 min 30 s. This is a maximum, so a time limit based on it is a worst case.
| Level | NIOSH limit (85 dBA, 3 dB rule) | OSHA limit (90 dBA, 5 dB rule) | UK/EU 80 dB(A) action value reached after | UK/EU 85 dB(A) action value reached after |
|---|---|---|---|---|
| 100 dBA | 15 min | 2 h | 4 min 48 s | 15 min |
| 120 dBA | 9 s | 7 min 30 s | 3 s | 9 s |
Times are for a whole day’s exposure, with the rest of the day quiet. The workplace limits were written for adults at work, not for children. Work out a mixed day with the noise dose calculator.
Pets
Many dogs are frightened by thunder. A quiet interior room with the curtains closed and a familiar background sound can help.
Protecting your hearing
Shelter indoors during storms, which also reduces the sound. If you are caught outside near frequent close strikes, covering your ears reduces the peak.
Earplug and earmuff ratings (NRR in the US, SNR in the UK and EU) are lab figures; real-world protection is usually lower. How to read the ratings.
Compared with sounds nearby
Using midpoints of each range. Energy multiplies by 10 every 10 dB; perceived loudness roughly doubles (why).
- Tank (moving) (96–117 dBA): this has about 2.2× its sound energy and sounds about 1.3× as loud.
- Piccolo (96–118 dBA): this has about 2× its sound energy and sounds about 1.2× as loud.
- Police siren (115–120 dBA): it has about 5.6× the sound energy of this and sounds about 1.7× as loud.
- Earbuds at full volume (115.5–120 dBA): it has about 6× the sound energy of this and sounds about 1.7× as loud.
- Normal conversation (55–70 dBA): this has about 56,234× its energy and sounds about 26.9× as loud.
Questions
How many decibels is thunder?
The National Park Service measured thunder at 100 dBA in Arches National Park and says a crack of thunder can exceed 120 decibels.
Can thunder damage your hearing?
The NPS says a close crack of thunder can exceed 120 dB, loud enough to cause pain. Being indoors cuts the level considerably.
Sources
- Understanding Sound - Natural Sounds, U.S. National Park Service. Supports: dB_low: 100 dBA.
100 Thunder (Arches National Park)
Checked 2026-11-02. - Understanding Sound - Natural Sounds, U.S. National Park Service. Supports: dB_high: can exceed 120 dB.
The crack of thunder can exceed 120 decibels, loud enough to cause pain to the human ear.
Checked 2026-11-02. - Noise Comparisons (Noise Sources and Their Effects), Purdue University Department of Chemistry, Chemical Safety. Supports: dB_high: thunderclap 120 dB.
Thunderclap, chain saw. Oxygen torch (121 dB). 120
Checked 2026-11-02. - Noise Comparisons (Noise Sources and Their Effects), Purdue University Department of Chemistry, Chemical Safety. Supports: body: 120 dB row labelled painful.
Painful. 32 times as loud as 70 dB.
Checked 2026-11-02.
This page is general information, not medical advice. If you have ringing in your ears, muffled hearing or any change in your hearing, see an audiologist or your doctor.