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SunnyDays

ERA5 almanac comparison — 8 years of real data

30A / Seaside vs Jacksonville: weather in December

Jacksonville edges out 30A / Seaside for sun in December: 16% clear historically versus 4% (8-year ERA5 average, a 12-point gap). Both are viable — Jacksonville 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.

30A / Seaside

FL

Clear days, December
4%
Sample size
n=248 days
Avg high
65°F
Early December (1st–15th)
2%
Late December (16th–end)
6%

Jacksonville

FL

Clear days, December
16%
Sample size
n=248 days
Avg high
67°F
Early December (1st–15th)
16%
Late December (16th–end)
16%
Rain frequency
22% of days

Compare 30A / Seaside vs Jacksonville 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.