ERA5 almanac comparison — 8 years of real data
Birmingham vs Charleston: weather in May
Essentially a tie in May: Birmingham is 36% clear historically, Charleston is 37% clear (8-year ERA5 average) — within the noise. Avg high 81°F vs 80°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Birmingham
AL
- Clear days, May
- 36%
- Sample size
- n=248 days
- Avg high
- 81°F
- Early May (1st–15th)
- 33%
- Late May (16th–end)
- 39%
- Rain frequency
- 38% of days
Charleston
SC
- Clear days, May
- 37%
- Sample size
- n=248 days
- Avg high
- 80°F
- Early May (1st–15th)
- 44%
- Late May (16th–end)
- 31%
- Rain frequency
- 40% of days
Frequently asked
Is Birmingham or Charleston warmer in May?
Birmingham runs warmer by day in May. Birmingham averages highs of 81°F (highs n=248 days); Charleston averages highs of 80°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Birmingham or Charleston in May?
Days with measurable rain: Birmingham 38%, Charleston 40% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in May, Birmingham or Charleston?
Essentially a tie in May: Birmingham is 36% clear historically, Charleston is 37% clear (8-year ERA5 average) — within the noise. Avg high 81°F vs 80°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Compare Birmingham vs Charleston 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.