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SunnyDays

ERA5 almanac — 8 years of real data

Sun Valley in July

Sun Valley in July: 10% of days see measurable rain, 83°F average high, 70% of days historically clear (n=248, ERA5 2018–2025).

Historically one of the better months to visit Sun Valley for sun: 70% of days are clear on average (n=248, avg high 83°F). Every percentage here is a historical average from 8 years of ERA5 data — 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 Sun Valley 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 Sun Valley 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		 70% n=120 83°F
Late July
16th–end		 70% n=128 83°F
Full month average 70% n=248 83°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 Sun Valley 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		 94% n=120
Late July
16th–end		 98% n=128
Full month average 96% n=248
14.5 h median sunshine per day 98% of days exceed 8 h sunshine 10% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 70%. Sunshine-based “warm & sunny”: 96%. The 26-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

Sun Valley clears solidly in July: 70% of days historically (n=248), avg high 83°F. Most trips here in July will find more sun than cloud.

Every month in Sun Valley

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

Historical clear-sky % for Sun Valley, 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 3% n=248 All destinations →
June 33% n=240 All destinations →
July ← this page 70% n=248 All destinations →
August 58% n=248 All destinations →
September 42% n=240 All destinations →
October 3% n=248 All destinations →
November 0% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Sun Valley in July?

Rarely. Only 10% of days in Sun Valley 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 Sun Valley good for sun in July?

Yes. Sun Valley is historically strong for sun in July: 70% of days are clear on average (avg high 83°F, n=248 days, ERA5 2018–2025).

How Sun Valley compares in July

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