ERA5 almanac — 8 years of real data

Atlanta in October

Atlanta in October: rain frequency data not yet backfilled for this month, 73°F average high, 34% of days historically clear (n=248, ERA5 2018–2025).

Atlanta in October is historically a poor month for sun: only 34% of days clear across 8 years (n=248, avg high 73°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 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 October

Clear-sky percentage for Atlanta 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	45%	n=120	73°F
Late October 16th–end	24%	n=128	73°F
Full month average	34%	n=248	73°F

Bottom line

Atlanta is mostly overcast in October historically: only 34% of days are clear across 8 years (n=248), avg high 73°F. The two halves differ materially (45% early, 24% late) — favour the early half of the month. Most visitors this month will see more clouds than sun.

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	20%	n=248	All destinations →
September	40%	n=240	All destinations →
October ← this page	34%	n=248	All destinations →
November	6%	n=240	All destinations →
December	1%	n=248	All destinations →

Frequently asked

Is Atlanta good for sun in October?

It's mixed. Atlanta in October is clear on 34% of days historically (avg high 73°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

→ Atlanta live forecast — this week’s actual 7-day weather, not historical
→ Best destinations in October — all destinations ranked by October clear-sky %
→ All destinations
→ Raw data (JSON) — buckets, n, source

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.