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SunnyDays

ERA5 almanac — 8 years of real data

Crater Lake in July

Crater Lake in July: 8% of days see measurable rain, 74°F average high, 52% of days historically clear (n=248, ERA5 2018–2025).

Crater Lake in July is a mixed month for sun: 52% of days historically clear (n=248, avg high 74°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 Crater Lake 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 July

Clear-sky percentage for Crater Lake in July, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early July
1st–15th		 45% n=120 74°F
Late July
16th–end		 59% n=128 74°F
Full month average 52% n=248 74°F

Sunshine & warmth in July

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 Crater Lake in July. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early July
1st–15th		 52% n=120
Late July
16th–end		 73% n=128
Full month average 63% n=248
14.6 h median sunshine per day 99% of days exceed 8 h sunshine 8% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 52%. Sunshine-based “warm & sunny”: 63%. The 11-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

Crater Lake in July is genuinely mixed: 52% of days historically clear (n=248), avg high 74°F — roughly even odds. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Crater Lake

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

Historical clear-sky % for Crater Lake, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 0% n=226 All destinations →
March 0% n=248 All destinations →
April 0% n=240 All destinations →
May 0% n=248 All destinations →
June 13% n=240 All destinations →
July ← this page 52% n=248 All destinations →
August 42% n=248 All destinations →
September 24% n=240 All destinations →
October 1% n=248 All destinations →
November 0% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Crater Lake in July?

Rarely. Only 8% of days in Crater Lake see measurable rain in July, based on 8 years of ERA5 historical data (n=248 days, 2018–2025). This is a historical average, not a forecast.

Is Crater Lake good for sun in July?

It's mixed. Crater Lake in July is clear on 52% of days historically (avg high 74°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Crater Lake compares in July

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