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SunnyDays

ERA5 almanac — 8 years of real data

Shenandoah Valley in May

Shenandoah Valley in May: 46% of days see measurable rain, 74°F average high, 18% of days historically clear (n=248, ERA5 2018–2025).

Shenandoah Valley in May is historically a poor month for sun: only 18% of days clear across 8 years (n=248, avg high 74°F). June is the clearest month for Shenandoah Valley historically. 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 May

Clear-sky percentage for Shenandoah Valley 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		 15% n=120 74°F
Late May
16th–end		 21% n=128 74°F
Full month average 18% n=248 74°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 Shenandoah Valley 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		 49% n=120
Late May
16th–end		 62% n=128
Full month average 56% n=248
12.0 h median sunshine per day 71% of days exceed 8 h sunshine 46% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 18%. Sunshine-based “warm & sunny”: 56%. The 38-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 a poor choice for sun in May: just 18% of days clear historically (n=248). June is the historically strongest month for sun here. The 8-year record is consistent — this is not a fluke bad stretch.

→ See all destinations in June — historically the best month for sun in Shenandoah Valley.

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 ← this page 18% n=248 All destinations →
June 39% n=240 All destinations →
July 34% n=248 All destinations →
August 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 May?

Sometimes. Shenandoah Valley sees measurable rain on 46% of days in May historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Shenandoah Valley good for sun in May?

Not usually. Shenandoah Valley is historically overcast in May: only 18% of days are clear (avg high 74°F, n=248 days, ERA5 2018–2025). June is historically far better for sun here.

How Shenandoah Valley compares in May

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.