Skip to main content
SunnyDays

ERA5 almanac — 8 years of real data

Montauk in August

Montauk in August: 31% of days see measurable rain, 73°F average high, 37% of days historically clear (n=248, ERA5 2018–2025).

Montauk in August is historically a poor month for sun: only 37% of days clear across 8 years (n=248, avg high 73°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 Montauk 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 Montauk 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		 39% n=120 73°F
Late August
16th–end		 35% n=128 73°F
Full month average 37% n=248 73°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 Montauk 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		 72% n=120
Late August
16th–end		 61% n=128
Full month average 66% n=248
12.7 h median sunshine per day 86% of days exceed 8 h sunshine 31% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 37%. Sunshine-based “warm & sunny”: 66%. The 29-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

Montauk is mostly overcast in August historically: only 37% of days are clear across 8 years (n=248), avg high 73°F. Most visitors this month will see more clouds than sun.

Every month in Montauk

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

Historical clear-sky % for Montauk, 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 0% n=248 All destinations →
June 2% n=240 All destinations →
July 29% n=248 All destinations →
August ← this page 37% n=248 All destinations →
September 10% n=240 All destinations →
October 0% n=248 All destinations →
November 0% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Montauk in August?

Sometimes. Montauk sees measurable rain on 31% of days in August historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Montauk good for sun in August?

It's mixed. Montauk in August is clear on 37% of days historically (avg high 73°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Montauk compares in August

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