ERA5 almanac — 8 years of real data

New York City in August

New York City in August: 42% of days see measurable rain, 83°F average high, 35% of days historically clear (n=248, ERA5 2018–2025).

New York City in August is historically a poor month for sun: only 35% 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 New York City 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 New York City 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	38%	n=128	83°F
Full month average	35%	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 New York City 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	89%	n=120
Late August 16th–end	84%	n=128
Full month average	86%	n=248

12.4 h median sunshine per day 81% of days exceed 8 h sunshine 42% of days see ≥ 1 mm rain — rain is not hidden

Comparison (old vs new): WMO-code “clear” bar: 35%. Sunshine-based “warm & sunny”: 86%. The 51-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

New York City is mostly overcast in August historically: only 35% 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 New York City

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

Historical clear-sky % for New York City, 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	6%	n=240	All destinations →
May	24%	n=248	All destinations →
June	39%	n=240	All destinations →
July	31%	n=248	All destinations →
August ← this page	35%	n=248	All destinations →
September	40%	n=240	All destinations →
October	13%	n=248	All destinations →
November	2%	n=240	All destinations →
December	0%	n=248	All destinations →

Frequently asked

Does it rain in New York City in August?

Sometimes. New York City sees measurable rain on 42% of days in August historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is New York City good for sun in August?

It's mixed. New York City in August is clear on 35% of days historically (avg high 83°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How New York City compares in August

Head-to-head clear-sky comparisons against destinations travelers plausibly weigh against New York City this month — same passport tier, similar flight distance, both sides from the same 8-year ERA5 record.

→ New York City vs Outer Banks in August — Outer Banks is 35% clear historically
→ New York City vs Albany in August — Albany is 34% clear historically
→ New York City vs Bar Harbor in August — Bar Harbor is 36% clear historically

→ New York City live forecast — this week’s actual 7-day weather, not historical
→ Best destinations in August — all destinations ranked by August clear-sky %
→ All destinations
→ Raw data (JSON) — buckets, n, source

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.