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SunnyDays

ERA5 almanac — 8 years of real data

St. Augustine in October

St. Augustine in October is historically a poor month for sun: only 34% 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 St. Augustine 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 St. Augustine 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		 39% n=128 79°F
Full month average 34% n=248 79°F

Sunshine & warmth in October

A second measure using actual sunshine hours (ERA5 sunshine_duration), not the daily weather code. A Lowcountry day with 12 hours of sun and a 25-minute afternoon storm is counted below as a warm, sunny day — because it was. How we define this.

Sunshine-based metrics for St. Augustine in October. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early October
1st–15th		 88% n=120
Late October
16th–end		 84% n=128
Full month average 86% n=248
10.7 h median sunshine per day 86% of days exceed 8 h sunshine 39% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 34%. Sunshine-based “warm & sunny”: 86%. The 52-point gap is from brief afternoon convective storms that stamp the whole day as “rain” in the WMO code but leave the bulk of the sunshine untouched.

Bottom line

St. Augustine is mostly overcast in October historically: only 34% 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 St. Augustine

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

Historical clear-sky % for St. Augustine, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 9% n=248 All destinations →
February 22% n=226 All destinations →
March 25% n=248 All destinations →
April 42% n=240 All destinations →
May 40% n=248 All destinations →
June 14% n=240 All destinations →
July 9% n=248 All destinations →
August 6% n=248 All destinations →
September 17% n=240 All destinations →
October ← this page 34% n=248 All destinations →
November 23% n=240 All destinations →
December 13% 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.