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SunnyDays

ERA5 almanac — 8 years of real data

Outer Banks in August

Outer Banks in August is historically a poor month for sun: only 35% of days clear across 8 years (n=248, avg high 81°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 Outer Banks 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 Outer Banks 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		 30% n=120 81°F
Late August
16th–end		 39% n=128 81°F
Full month average 35% n=248 81°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 Outer Banks 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		 88% n=120
Late August
16th–end		 93% n=128
Full month average 91% n=248
12.1 h median sunshine per day 84% of days exceed 8 h sunshine 44% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 35%. Sunshine-based “warm & sunny”: 91%. The 56-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

Outer Banks is mostly overcast in August historically: only 35% of days are clear across 8 years (n=248), avg high 81°F. Most visitors this month will see more clouds than sun.

Every month in Outer Banks

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

Historical clear-sky % for Outer Banks, 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 1% n=240 All destinations →
May 16% n=248 All destinations →
June 47% n=240 All destinations →
July 35% n=248 All destinations →
August ← this page 35% n=248 All destinations →
September 40% n=240 All destinations →
October 20% n=248 All destinations →
November 1% n=240 All destinations →
December 0% n=248 All destinations →

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.