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SunnyDays

ERA5 almanac — 8 years of real data

Atlanta in August

Atlanta in August: 59% of days see measurable rain, 86°F average high, 20% of days historically clear (n=248, ERA5 2018–2025).

Atlanta in August is historically a poor month for sun: only 20% of days clear across 8 years (n=248, avg high 86°F). September is the clearest month for Atlanta 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 Atlanta 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 Atlanta 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		 14% n=120 86°F
Late August
16th–end		 25% n=128 86°F
Full month average 20% 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 Atlanta 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		 85% n=128
Full month average 89% n=248
12.0 h median sunshine per day 84% of days exceed 8 h sunshine 59% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 20%. Sunshine-based “warm & sunny”: 89%. The 69-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

Atlanta is mostly overcast in August historically: only 20% of days are clear across 8 years (n=248), avg high 86°F. If you want sun in Atlanta, September is historically much better. Most visitors this month will see more clouds than sun.

→ See all destinations in September — historically the best month for sun in Atlanta.

Every month in Atlanta

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

Historical clear-sky % for Atlanta, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 2% n=226 All destinations →
March 11% n=248 All destinations →
April 24% n=240 All destinations →
May 32% n=248 All destinations →
June 26% n=240 All destinations →
July 15% n=248 All destinations →
August ← this page 20% n=248 All destinations →
September 40% n=240 All destinations →
October 34% n=248 All destinations →
November 6% n=240 All destinations →
December 1% n=248 All destinations →

Frequently asked

Does it rain in Atlanta in August?

Yes, frequently. In Atlanta, 59% of days in August see measurable rain, based on 8 years of ERA5 historical data (n=248 days, 2018–2025). This is a historical average, not a forecast.

Is Atlanta good for sun in August?

Not usually. Atlanta is historically overcast in August: only 20% of days are clear (avg high 86°F, n=248 days, ERA5 2018–2025). September is historically far better for sun here.

How Atlanta compares in August

Head-to-head clear-sky comparisons against destinations travelers plausibly weigh against Atlanta this month — same passport tier, similar flight distance, both sides from the same 8-year ERA5 record.

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.