ERA5 almanac comparison — 8 years of real data
Martha's Vineyard vs Sea Island: weather in March
Sea Island edges out Martha's Vineyard for sun in March: 15% clear historically versus 0% (8-year ERA5 average, a 15-point gap). Both are viable — Sea Island is the safer bet.
Martha's Vineyard
MA
- Clear days, March
- 0%
- Sample size
- n=248 days
- Avg high
- 46°F
- Early March (1st–15th)
- 0%
- Late March (16th–end)
- 0%
- Rain frequency
- 36% of days
Sea Island
GA
- Clear days, March
- 15%
- Sample size
- n=248 days
- Avg high
- 69°F
- Early March (1st–15th)
- 12%
- Late March (16th–end)
- 17%
- Rain frequency
- 29% of days
Frequently asked
Is Martha's Vineyard or Sea Island warmer in March?
Sea Island runs warmer by day in March. Martha's Vineyard averages highs of 46°F (highs n=248 days); Sea Island averages highs of 69°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Martha's Vineyard or Sea Island in March?
Days with measurable rain: Martha's Vineyard 36%, Sea Island 29% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in March, Martha's Vineyard or Sea Island?
Sea Island edges out Martha's Vineyard for sun in March: 15% clear historically versus 0% (8-year ERA5 average, a 15-point gap). Both are viable — Sea Island is the safer bet.
Compare Martha's Vineyard vs Sea Island in another month
All percentages are historical averages from the ERA5 reanalysis via Open-Meteo, 8 full years (2018–2025). “Clear” means avg high ≥ 72 °F, precipitation < 1 mm, and a non-precipitation weather code. This is history, not a forecast. The live forecast for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.