Skip to main content
SunnyDays

ERA5 almanac — 8 years of real data

St. Augustine in August

St. Augustine in August is historically a poor month for sun: only 6% of days clear across 8 years (n=248, avg high 86°F). April is the clearest month for St. Augustine historically. 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 August

Clear-sky percentage for St. Augustine in August, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early August
1st–15th		 6% n=120 86°F
Late August
16th–end		 6% n=128 86°F
Full month average 6% n=248 86°F

Sunshine & warmth in August

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 August. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early August
1st–15th		 93% n=120
Late August
16th–end		 91% n=128
Full month average 92% n=248
12.1 h median sunshine per day 88% of days exceed 8 h sunshine 75% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 6%. Sunshine-based “warm & sunny”: 92%. The 86-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 a poor choice for sun in August: just 6% of days clear historically (n=248). April is the historically strongest month for sun here. The 8-year record is consistent — this is not a fluke bad stretch.

→ See all destinations in April — historically the best month for sun in St. Augustine.

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 ← this page 6% n=248 All destinations →
September 17% n=240 All destinations →
October 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.