ERA5 almanac comparison — 8 years of real data
Boston vs San Antonio: weather in June
Essentially a tie in June: Boston is 33% clear historically, San Antonio is 31% clear (8-year ERA5 average) — within the noise. Avg high 78°F vs 94°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 June. For this
week’s actual forecast, each destination links to its live page below.
Boston
MA
- Clear days, June
- 33%
- Sample size
- n=240 days
- Avg high
- 78°F
- Early June (1st–15th)
- 32%
- Late June (16th–end)
- 34%
San Antonio
TX
- Clear days, June
- 31%
- Sample size
- n=240 days
- Avg high
- 94°F
- Early June (1st–15th)
- 32%
- Late June (16th–end)
- 30%
- Rain frequency
- 36% of days
Compare Boston vs San Antonio 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.