ERA5 almanac — 8 years of real data

Rome in October

Rome in October: 35% of days see measurable rain, 73°F average high, 38% of days historically clear (n=248, ERA5 2018–2025).

Rome in October is historically a poor month for sun: only 38% 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 Rome 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 Rome 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	42%	n=120	73°F
Late October 16th–end	35%	n=128	73°F
Full month average	38%	n=248	73°F

Sunshine & warmth in October

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 Rome in October. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period	Warm & sunny (≥72°F, >6 h sun)	Sample (n)
Early October 1st–15th	67%	n=120
Late October 16th–end	53%	n=128
Full month average	60%	n=248

10.1 h median sunshine per day 77% of days exceed 8 h sunshine 35% of days see ≥ 1 mm rain — rain is not hidden

Comparison (old vs new): WMO-code “clear” bar: 38%. Sunshine-based “warm & sunny”: 60%. The 22-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

Rome is mostly overcast in October historically: only 38% of days are clear across 8 years (n=248), avg high 73°F. Most visitors this month will see more clouds than sun.

Every month in Rome

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

Historical clear-sky % for Rome, all months, ERA5 2018–2025.
Month	% Clear	Sample (n)
January	0%	n=248	All destinations →
February	0%	n=226	All destinations →
March	2%	n=248	All destinations →
April	16%	n=240	All destinations →
May	30%	n=248	All destinations →
June	65%	n=240	All destinations →
July	77%	n=248	All destinations →
August	59%	n=248	All destinations →
September	50%	n=240	All destinations →
October ← this page	38%	n=248	All destinations →
November	2%	n=240	All destinations →
December	0%	n=248	All destinations →

Frequently asked

Does it rain in Rome in October?

Sometimes. Rome sees measurable rain on 35% of days in October historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Rome good for sun in October?

It's mixed. Rome in October is clear on 38% of days historically (avg high 73°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Rome compares in October

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

→ Rome vs Madrid in October — Madrid is 38% clear historically
→ Rome vs Mykonos in October — Mykonos is 39% clear historically
→ Rome vs Mallorca in October — Mallorca is 40% clear historically

→ Rome 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.