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SunnyDays

ERA5 almanac — 8 years of real data

Savannah in June

Savannah in June is historically a poor month for sun: only 24% of days clear across 8 years (n=240, avg high 88°F). October is the clearest month for Savannah 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 Savannah 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 June

Clear-sky percentage for Savannah in June, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early June
1st–15th
20% n=120 88°F
Late June
16th–end
28% n=120 88°F
Full month average 24% n=240 88°F

Sunshine & warmth in June

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 Savannah in June. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early June
1st–15th
87% n=120
Late June
16th–end
96% n=120
Full month average 92% n=240
12.1 h median sunshine per day 88% of days exceed 8 h sunshine 56% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 24%. Sunshine-based “warm & sunny”: 92%. The 68-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

Savannah is mostly overcast in June historically: only 24% of days are clear across 8 years (n=240), avg high 88°F. If you want sun in Savannah, October is historically much better. Most visitors this month will see more clouds than sun.

See all destinations in October — historically the best month for sun in Savannah.

Every month in Savannah

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

Historical clear-sky % for Savannah, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 2% n=248 All destinations →
February 16% n=226 All destinations →
March 25% n=248 All destinations →
April 44% n=240 All destinations →
May 37% n=248 All destinations →
June ← this page 24% n=240 All destinations →
July 14% n=248 All destinations →
August 8% n=248 All destinations →
September 32% n=240 All destinations →
October 47% n=248 All destinations →
November 18% n=240 All destinations →
December 8% 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.