ERA5 almanac — 8 years of real data

Atlanta in May

Atlanta in May: rain frequency data not yet backfilled for this month, 80°F average high, 32% of days historically clear (n=248, ERA5 2018–2025).

Atlanta in May is historically a poor month for sun: only 32% of days clear across 8 years (n=248, avg high 80°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 May

Clear-sky percentage for Atlanta in May, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period	% Clear days	Sample (n)	Avg high
Early May 1st–15th	26%	n=120	80°F
Late May 16th–end	37%	n=128	80°F
Full month average	32%	n=248	80°F

Bottom line

Atlanta is mostly overcast in May historically: only 32% of days are clear across 8 years (n=248), avg high 80°F. 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 ← this page	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	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 May?

It's mixed. Atlanta in May is clear on 32% of days historically (avg high 80°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 May — all destinations ranked by May 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.