ERA5 almanac — 8 years of real data

San Diego in June

San Diego in June: 2% of days see measurable rain, 72°F average high, 38% of days historically clear (n=240, ERA5 2018–2025).

San Diego in June is historically a poor month for sun: only 38% of days clear across 8 years (n=240, avg high 72°F). 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 San Diego 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 June

Clear-sky percentage for San Diego in June, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period	% Clear days	Sample (n)	Avg high
Early June 1st–15th	30%	n=120	72°F
Late June 16th–end	45%	n=120	72°F
Full month average	38%	n=240	72°F

Sunshine & warmth in June

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 San Diego in June. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period	Warm & sunny (≥72°F, >6 h sun)	Sample (n)
Early June 1st–15th	32%	n=120
Late June 16th–end	48%	n=120
Full month average	40%	n=240

11.7 h median sunshine per day 92% of days exceed 8 h sunshine 2% of days see ≥ 1 mm rain — rain is not hidden

Comparison (old vs new): WMO-code “clear” bar: 38%. Sunshine-based “warm & sunny”: 40%. The two measures are nearly identical here — no convective-storm bias for this climate and month.

Bottom line

San Diego is mostly overcast in June historically: only 38% of days are clear across 8 years (n=240), avg high 72°F. Most visitors this month will see more clouds than sun.

Every month in San Diego

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

Historical clear-sky % for San Diego, all months, ERA5 2018–2025.
Month	% Clear	Sample (n)
January	6%	n=248	All destinations →
February	12%	n=226	All destinations →
March	6%	n=248	All destinations →
April	13%	n=240	All destinations →
May	13%	n=248	All destinations →
June ← this page	38%	n=240	All destinations →
July	88%	n=248	All destinations →
August	90%	n=248	All destinations →
September	79%	n=240	All destinations →
October	60%	n=248	All destinations →
November	28%	n=240	All destinations →
December	6%	n=248	All destinations →

Frequently asked

Does it rain in San Diego in June?

Rarely. Only 2% of days in San Diego see measurable rain in June, based on 8 years of ERA5 historical data (n=240 days, 2018–2025). This is a historical average, not a forecast.

Is San Diego good for sun in June?

It's mixed. San Diego in June is clear on 38% of days historically (avg high 72°F, n=240 days, ERA5 2018–2025) — the outcome varies year to year.

How San Diego compares in June

Head-to-head clear-sky comparisons against destinations travelers plausibly weigh against San Diego this month — same passport tier, similar flight distance, both sides from the same 8-year ERA5 record.

→ San Diego vs Bozeman in June — Bozeman is 38% clear historically
→ San Diego vs Dallas in June — Dallas is 38% clear historically
→ San Diego vs Memphis in June — Memphis is 38% clear historically

→ San Diego live forecast — this week’s actual 7-day weather, not historical
→ Best destinations in June — all destinations ranked by June clear-sky %
→ All destinations
→ Raw data (JSON) — buckets, n, source

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.