Acadia National Park · Maine

Thunder Hole Live: Best Time to Hear the Boom Today

NPS recommends arriving about one to two hours before high tide. This tool checks whether the ocean has enough wave energy to make that timing worth the stop.

Thunder Potential is a modeled 0–100 index, not a probability. Safety and access are evaluated separately.

Loading NOAA and NWS data…

Thunder Potential

—/100

Checking conditions…

Tide and wave observations are loading.

Visit status—

Confidence—

Best peak today—

Next high tide—

Time to high—

Wave observation—

Park access status is checked independently from spectacle conditions.

Next 72 hours

Best upcoming Thunder Hole windows

If trustworthy wave guidance is unavailable, this section intentionally stays sparse rather than guessing.

Building windows…

Live ingredients

What the engine is seeing

Offshore wave height—

Dominant period—

Wave direction—

Observed water level—

Water-level residual—

Offshore wind—

How to use this

When should you actually go?

GO NOW is only issued when physical conditions are favorable and automated access verification is available. CHECK ACCESS means the spectacle model can run but NPS access could not be automatically verified. HAZARDOUS CONDITIONS or CLOSED overrides the trip recommendation even when Thunder Potential is high.

At Thunder Hole, bigger is not automatically better. NPS warns about rogue waves, wet granite and storm surf. Stay behind railings and follow posted closures.

Quick answers

Thunder Hole timing FAQ

What is the best time to visit Thunder Hole?

The National Park Service recommends roughly one to two hours before high tide for the best chance of hearing the boom. This tool refines that window using actual wave energy because the right tide can still be quiet when the ocean is calm.

Is high tide itself best?

Not necessarily. NPS guidance points to the rising-tide period before high tide, and the model uses a smooth timing curve centered in that pre-high window.

Can a high score be unsafe?

Yes. Strong surf can increase the spectacle and the danger at the same time. The physical score and Visit Status are intentionally separate.

Why is the score not a percent chance?

There is not enough direct outcome data to calibrate a true probability. The 0–100 number is an opportunity index, not an 84% claim.