ERA5 almanac comparison — 8 years of real data
Cape Cod vs Portland: weather in April
Essentially a tie in April: Cape Cod is 2% clear historically, Portland is 2% clear (8-year ERA5 average) — within the noise. Avg high 54°F vs 52°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
What you are reading: 8-year historical averages, not a forecast.
Either destination can still surprise you this specific April. For this
week’s actual forecast, each destination links to its live page below.
Cape Cod
MA
- Clear days, April
- 2%
- Sample size
- n=240 days
- Avg high
- 54°F
- Early April (1st–15th)
- 2%
- Late April (16th–end)
- 1%
Portland
ME
- Clear days, April
- 2%
- Sample size
- n=240 days
- Avg high
- 52°F
- Early April (1st–15th)
- 1%
- Late April (16th–end)
- 2%
Compare Cape Cod vs Portland 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 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.