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SunnyDays

ERA5 almanac — 8 years of real data

Barcelona in August

Barcelona in August: 21% of days see measurable rain, 84°F average high, 53% of days historically clear (n=248, ERA5 2018–2025).

Barcelona in August is a mixed month for sun: 53% of days historically clear (n=248, avg high 84°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 Barcelona 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 August

Clear-sky percentage for Barcelona in August, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early August
1st–15th		 64% n=120 84°F
Late August
16th–end		 43% n=128 84°F
Full month average 53% n=248 84°F

Sunshine & warmth in August

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 Barcelona in August. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early August
1st–15th		 99% n=120
Late August
16th–end		 96% n=128
Full month average 97% n=248
13.0 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: 53%. Sunshine-based “warm & sunny”: 97%. The 44-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

Barcelona in August is genuinely mixed: 53% of days historically clear (n=248), avg high 84°F — roughly even odds. The two halves differ materially (64% early, 43% late) — favour the early half of the month. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Barcelona

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

Historical clear-sky % for Barcelona, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 0% n=226 All destinations →
March 3% n=248 All destinations →
April 4% n=240 All destinations →
May 25% n=248 All destinations →
June 61% n=240 All destinations →
July 64% n=248 All destinations →
August ← this page 53% n=248 All destinations →
September 38% n=240 All destinations →
October 27% n=248 All destinations →
November 4% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Barcelona in August?

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

Is Barcelona good for sun in August?

It's mixed. Barcelona in August is clear on 53% of days historically (avg high 84°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Barcelona compares in August

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