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SunnyDays

ERA5 almanac — 8 years of real data

Seville in September

Seville in September: 13% of days see measurable rain, 89°F average high, 76% of days historically clear (n=240, ERA5 2018–2025).

Historically one of the better months to visit Seville for sun: 76% of days are clear on average (n=240, avg high 89°F). Every percentage here is a historical average from 8 years of ERA5 data — 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 Seville 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 Seville 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		 79% n=120 89°F
Late September
16th–end		 74% n=120 89°F
Full month average 76% n=240 89°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 Seville 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		 98% n=120
Late September
16th–end		 96% n=120
Full month average 97% n=240
11.7 h median sunshine per day 94% of days exceed 8 h sunshine 13% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 76%. Sunshine-based “warm & sunny”: 97%. The 21-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

Seville clears solidly in September: 76% of days historically (n=240), avg high 89°F. Most trips here in September will find more sun than cloud.

Every month in Seville

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

Historical clear-sky % for Seville, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 1% n=248 All destinations →
February 11% n=226 All destinations →
March 26% n=248 All destinations →
April 40% n=240 All destinations →
May 74% n=248 All destinations →
June 82% n=240 All destinations →
July 99% n=248 All destinations →
August 96% n=248 All destinations →
September ← this page 76% n=240 All destinations →
October 63% n=248 All destinations →
November 16% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Seville in September?

Rarely. Only 13% of days in Seville see measurable rain in September, based on 8 years of ERA5 historical data (n=240 days, 2018–2025). This is a historical average, not a forecast.

Is Seville good for sun in September?

Yes. Seville is historically strong for sun in September: 76% of days are clear on average (avg high 89°F, n=240 days, ERA5 2018–2025).

How Seville compares in September

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