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SunnyDays

ERA5 almanac — 8 years of real data

Jacksonville in October

Jacksonville in October is historically a poor month for sun: only 33% of days clear across 8 years (n=248, avg high 79°F). Historical average, not a forecast.

What you are reading: 8-year historical averages from the ERA5 reanalysis, not a forecast. A month that is historically 90% clear can still be overcast on your specific trip. For this week’s actual forecast, see the live Jacksonville page. Both can be true at once: “historically strong in this month; this particular week is not.” We label which is which.

Early vs. Late October

Clear-sky percentage for Jacksonville in October, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early October
1st–15th		 28% n=120 79°F
Late October
16th–end		 37% n=128 79°F
Full month average 33% n=248 79°F

Bottom line

Jacksonville is mostly overcast in October historically: only 33% of days are clear across 8 years (n=248), avg high 79°F. Most visitors this month will see more clouds than sun.

Every month in Jacksonville

Compare across all months with data. Numbers are historical clear-sky %.

Historical clear-sky % for Jacksonville, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 9% n=248 All destinations →
February 27% n=226 All destinations →
March 37% n=248 All destinations →
April 48% n=240 All destinations →
May 41% n=248 All destinations →
June 15% n=240 All destinations →
July 8% n=248 All destinations →
August 7% n=248 All destinations →
September 22% n=240 All destinations →
October ← this page 33% n=248 All destinations →
November 24% n=240 All destinations →
December 16% n=248 All destinations →

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.