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SunnyDays

ERA5 almanac — 8 years of real data

Los Angeles in May

Los Angeles in May is a mixed month for sun: 69% 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 Los Angeles 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 Los Angeles 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		 70% n=120 76°F
Late May
16th–end		 68% n=128 76°F
Full month average 69% 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 Los Angeles 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		 80% n=120
Late May
16th–end		 77% n=128
Full month average 78% n=248
11.4 h median sunshine per day 89% of days exceed 8 h sunshine 7% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 69%. Sunshine-based “warm & sunny”: 78%.

Bottom line

Los Angeles clears solidly in May: 69% of days historically (n=248), avg high 76°F. Most trips here in May will find more sun than cloud.

Every month in Los Angeles

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

Historical clear-sky % for Los Angeles, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 23% n=248 All destinations →
February 27% n=226 All destinations →
March 25% n=248 All destinations →
April 60% n=240 All destinations →
May ← this page 69% n=248 All destinations →
June 88% n=240 All destinations →
July 96% n=248 All destinations →
August 95% n=248 All destinations →
September 87% n=240 All destinations →
October 86% n=248 All destinations →
November 61% n=240 All destinations →
December 21% n=248 All destinations →

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.