ERA5 almanac comparison — 8 years of real data
Charleston vs Houston: weather in December
Essentially a tie in December: Charleston is 2% clear historically, Houston is 6% clear (8-year ERA5 average) — within the noise. Avg high 61°F vs 67°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Charleston
SC
- Clear days, December
- 2%
- Sample size
- n=248 days
- Avg high
- 61°F
- Early December (1st–15th)
- 1%
- Late December (16th–end)
- 3%
- Rain frequency
- 30% of days
Houston
TX
- Clear days, December
- 6%
- Sample size
- n=248 days
- Avg high
- 67°F
- Early December (1st–15th)
- 5%
- Late December (16th–end)
- 6%
- Rain frequency
- 37% of days
Frequently asked
Is Charleston or Houston warmer in December?
Houston runs warmer by day in December. Charleston averages highs of 61°F (highs n=248 days); Houston averages highs of 67°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Charleston or Houston in December?
Days with measurable rain: Charleston 30%, Houston 37% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in December, Charleston or Houston?
Essentially a tie in December: Charleston is 2% clear historically, Houston is 6% clear (8-year ERA5 average) — within the noise. Avg high 61°F vs 67°F. Pick based on flight time or price, not weather — the weather won't decide this one for you.
Compare Charleston vs Houston 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.