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SunnyDays

ERA5 almanac — 8 years of real data

Madrid in May

Madrid in May: 21% of days see measurable rain, 76°F average high, 51% of days historically clear (n=248, ERA5 2018–2025).

Madrid in May is a mixed month for sun: 51% of days historically clear (n=248, avg high 76°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 Madrid 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 Madrid 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		 39% n=120 76°F
Late May
16th–end		 62% n=128 76°F
Full month average 51% n=248 76°F

Sunshine & warmth in May

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 Madrid in May. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early May
1st–15th		 55% n=120
Late May
16th–end		 77% n=128
Full month average 66% n=248
13.5 h median sunshine per day 96% of days exceed 8 h sunshine 21% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 51%. Sunshine-based “warm & sunny”: 66%. The 15-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

Madrid in May is genuinely mixed: 51% of days historically clear (n=248), avg high 76°F — roughly even odds. The two halves differ materially (39% early, 62% late) — favour the late half of the month. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Madrid

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

Historical clear-sky % for Madrid, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 0% n=226 All destinations →
March 9% n=248 All destinations →
April 20% n=240 All destinations →
May ← this page 51% n=248 All destinations →
June 67% n=240 All destinations →
July 91% n=248 All destinations →
August 88% n=248 All destinations →
September 62% n=240 All destinations →
October 38% n=248 All destinations →
November 0% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Madrid in May?

Sometimes. Madrid sees measurable rain on 21% of days in May historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Madrid good for sun in May?

It's mixed. Madrid in May is clear on 51% of days historically (avg high 76°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Madrid compares in May

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