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SunnyDays

ERA5 almanac — 8 years of real data

Shenandoah Valley in August

Shenandoah Valley in August: 39% of days see measurable rain, 83°F average high, 34% of days historically clear (n=248, ERA5 2018–2025).

Shenandoah Valley in August is historically a poor month for sun: only 34% of days clear across 8 years (n=248, avg high 83°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 Shenandoah 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 August

Clear-sky percentage for Shenandoah Valley 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		 32% n=120 83°F
Late August
16th–end		 36% n=128 83°F
Full month average 34% n=248 83°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 Shenandoah Valley 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		 91% n=120
Late August
16th–end		 91% n=128
Full month average 91% n=248
12.2 h median sunshine per day 87% of days exceed 8 h sunshine 39% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 34%. Sunshine-based “warm & sunny”: 91%. The 57-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

Shenandoah Valley is mostly overcast in August historically: only 34% of days are clear across 8 years (n=248), avg high 83°F. Most visitors this month will see more clouds than sun.

Every month in Shenandoah Valley

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

Historical clear-sky % for Shenandoah Valley, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 1% n=226 All destinations →
March 2% n=248 All destinations →
April 14% n=240 All destinations →
May 18% n=248 All destinations →
June 39% n=240 All destinations →
July 34% n=248 All destinations →
August ← this page 34% n=248 All destinations →
September 36% n=240 All destinations →
October 17% n=248 All destinations →
November 4% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Shenandoah Valley in August?

Sometimes. Shenandoah Valley sees measurable rain on 39% of days in August historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Shenandoah Valley good for sun in August?

It's mixed. Shenandoah Valley in August is clear on 34% of days historically (avg high 83°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Shenandoah Valley compares in August

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