Does the wind pick up on full moon days?
No difference
A belief long shared among sailors and fishermen. So far, no sail-worthy difference shows up in the statistics.
Tokyo
- Daily maximum wind speed (average)
- 20.4 km/h
- Full moon days (±24h)
- 20.6 km/h
- New moon days (±24h)
- 20.2 km/h
- Verdict for full moon days
- No difference
London
- Daily maximum wind speed (average)
- 20.5 km/h
- Full moon days (±24h)
- 20.6 km/h
- New moon days (±24h)
- 20.7 km/h
- Verdict for full moon days
- No difference
New York
- Daily maximum wind speed (average)
- 17.8 km/h
- Full moon days (±24h)
- 17.7 km/h
- New moon days (±24h)
- 17.6 km/h
- Verdict for full moon days
- No difference
Data: 1940–2025, ERA5 reanalysis via Open-Meteo
Act II: If not the moon, what makes the wind blow?
Came looking for a difference? Here is a real one.
×1.3
In New York, the windiest month (March) averages about 1.3x the wind speed of the calmest month (August). What decides the wind is not the moon phase — it is the season.
The strongest gust in this dataset is 135 km/h (November 25, 1950). Storms are brought by low-pressure systems and hurricanes, not by full moons.
Plan around the wind by the forecast, not the moon.
The "moon brings the wind" folklore
"It blows around the full moon." "Moonlit nights are calm." Maritime and mountain folklore preserves sayings about wind and the moon in both directions. Sailors and fishermen have navigated by moon phases for centuries, and since the tides (which the moon really does drive) and the wind blend into one "mood of the sea," linking the two was a natural step.
But the moon's involvement in tides and in wind is of entirely different magnitudes. Tides are driven directly by lunar gravity; wind is driven by pressure differences — that is, by the sun heating the atmosphere unevenly. This page checks "is it windier on full moon days?" against 80+ years of wind records in three cities.
How this verdict is computed
- Data: daily maximum wind speed (10m above ground) from ERA5 (the European reanalysis dataset, since 1940) for three cities — Tokyo, London, and New York — to check whether the conclusion survives a change of location
- Unlike rainfall, wind speed is not a mostly-zero skewed quantity, so averages can be compared directly rather than via a rainy-day-style rate
- Wind is strongly seasonal (Tokyo's spring gales, London's winter storms), so each day is compared with the average wind speed for the same month
- Days are classified as full moon days (±24h around the instant) or new moon days using the moon age at local noon; each group's mean index is compared with 1.00
See the methodology for the exact criteria.
The moon does pull on the atmosphere — barely
Lunar gravity acts on the atmosphere as well as the oceans, producing a tiny pressure wave known as the atmospheric tide. The lunar component amounts to a few tens of pascals at the surface — far smaller than a single isobar on a weather map (hundreds of pascals), and like the ~1% precipitation modulation discussed on the rain page, at the edge of what long-term statistics can detect at all.
So "the moon touches the atmosphere" is real physics. It is nowhere near the size that would matter for setting sail or hanging out the laundry.
Sources
- Open-Meteo Historical Weather API (ERA5 reanalysis, CC BY 4.0) / ERA5: Copernicus Climate Change Service
- Moon phase instants computed in-house from Jean Meeus, "Astronomical Algorithms" (UTC)
Last updated: June 12, 2026 16:56 UTC (rebuilt daily)