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SunnyDays

ERA5 almanac — 8 years of real data

Sicily in September

Sicily in September: 24% of days see measurable rain, 82°F average high, 58% of days historically clear (n=240, ERA5 2018–2025).

Sicily in September is a mixed month for sun: 58% of days historically clear (n=240, avg high 82°F). The outcome varies year to year — check the early/late split below. 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 Sicily 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 September

Clear-sky percentage for Sicily in September, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early September
1st–15th		 57% n=120 82°F
Late September
16th–end		 58% n=120 82°F
Full month average 58% n=240 82°F

Sunshine & warmth in September

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 Sicily in September. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early September
1st–15th		 96% n=120
Late September
16th–end		 86% n=120
Full month average 91% n=240
11.8 h median sunshine per day 94% of days exceed 8 h sunshine 24% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 58%. Sunshine-based “warm & sunny”: 91%. The 33-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

Sicily in September is genuinely mixed: 58% of days historically clear (n=240), avg high 82°F — more clear than cloudy. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Sicily

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

Historical clear-sky % for Sicily, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 0% n=226 All destinations →
March 1% n=248 All destinations →
April 10% n=240 All destinations →
May 39% n=248 All destinations →
June 73% n=240 All destinations →
July 91% n=248 All destinations →
August 73% n=248 All destinations →
September ← this page 58% n=240 All destinations →
October 33% n=248 All destinations →
November 2% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Sicily in September?

Sometimes. Sicily sees measurable rain on 24% of days in September historically (n=240 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Sicily good for sun in September?

It's mixed. Sicily in September is clear on 58% of days historically (avg high 82°F, n=240 days, ERA5 2018–2025) — the outcome varies year to year.

How Sicily compares in September

Head-to-head clear-sky comparisons against destinations travelers plausibly weigh against Sicily 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.