ERA5 almanac comparison — 8 years of real data
Savannah vs St. John, USVI: weather in December
St. John, USVI edges out Savannah for sun in December: 16% clear historically versus 8% (8-year ERA5 average, a 8-point gap). St. John, USVI also sees measurably more rain than Savannah this month (44% vs 27% of days). Both are viable — St. John, USVI is the safer bet.
What you are reading: 8-year historical averages, not a forecast.
Either destination can still surprise you this specific December. For this
week’s actual forecast, each destination links to its live page below.
Savannah
GA
- Clear days, December
- 8%
- Sample size
- n=248 days
- Avg high
- 63°F
- Early December (1st–15th)
- 7%
- Late December (16th–end)
- 9%
- Rain frequency
- 27% of days
St. John, USVI
VI
- Clear days, December
- 16%
- Sample size
- n=248 days
- Avg high
- 76°F
- Early December (1st–15th)
- 12%
- Late December (16th–end)
- 20%
- Rain frequency
- 44% of days
Compare Savannah vs St. John, USVI 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.