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SunnyDays

ERA5 almanac — 8 years of real data

Hudson Valley in May

Hudson Valley in May: 43% of days see measurable rain, 71°F average high, 20% of days historically clear (n=248, ERA5 2018–2025).

Hudson Valley in May is historically a poor month for sun: only 20% of days clear across 8 years (n=248, avg high 71°F). June is the clearest month for Hudson 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 Hudson 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 Hudson 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		 10% n=120 71°F
Late May
16th–end		 29% n=128 71°F
Full month average 20% n=248 71°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 Hudson 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		 25% n=120
Late May
16th–end		 49% n=128
Full month average 37% n=248
11.8 h median sunshine per day 68% of days exceed 8 h sunshine 43% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 20%. Sunshine-based “warm & sunny”: 37%. The 17-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

Hudson Valley is mostly overcast in May historically: only 20% of days are clear across 8 years (n=248), avg high 71°F. If you want sun in Hudson Valley, June is historically much better. Most visitors this month will see more clouds than sun.

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

Every month in Hudson Valley

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

Historical clear-sky % for Hudson 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 4% n=240 All destinations →
May ← this page 20% n=248 All destinations →
June 38% n=240 All destinations →
July 33% n=248 All destinations →
August 37% n=248 All destinations →
September 33% n=240 All destinations →
October 11% n=248 All destinations →
November 1% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Hudson Valley in May?

Sometimes. Hudson Valley sees measurable rain on 43% of days in May historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Hudson Valley good for sun in May?

Not usually. Hudson Valley is historically overcast in May: only 20% of days are clear (avg high 71°F, n=248 days, ERA5 2018–2025). June is historically far better for sun here.

How Hudson Valley compares in May

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