ERA5 almanac — 8 years of real data

Wilmington in January

Wilmington in January: rain frequency data not yet backfilled for this month, 55°F average high, 1% of days historically clear (n=248, ERA5 2018–2025).

Wilmington in January is historically a poor month for sun: only 1% of days clear across 8 years (n=248, avg high 55°F). October is the clearest month for Wilmington 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 Wilmington 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 January

Clear-sky percentage for Wilmington in January, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period	% Clear days	Sample (n)	Avg high
Early January 1st–15th	1%	n=120	55°F
Late January 16th–end	1%	n=128	55°F
Full month average	1%	n=248	55°F

Bottom line

Wilmington is historically almost never clear in January: only 1% of days meet the clear bar across 8 years (n=248). Come back in October if you want clear skies here. Plan entirely around indoor or overcast-friendly activities.

→ See all destinations in October — historically the best month for sun in Wilmington.

Every month in Wilmington

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

Historical clear-sky % for Wilmington, all months, ERA5 2018–2025.
Month	% Clear	Sample (n)
January ← this page	1%	n=248	All destinations →
February	7%	n=226	All destinations →
March	12%	n=248	All destinations →
April	32%	n=240	All destinations →
May	34%	n=248	All destinations →
June	22%	n=240	All destinations →
July	16%	n=248	All destinations →
August	19%	n=248	All destinations →
September	36%	n=240	All destinations →
October	40%	n=248	All destinations →
November	8%	n=240	All destinations →
December	3%	n=248	All destinations →

Frequently asked

Is Wilmington good for sun in January?

Not usually. Wilmington is historically overcast in January: only 1% of days are clear (avg high 55°F, n=248 days, ERA5 2018–2025). October is historically far better for sun here.

→ Wilmington live forecast — this week’s actual 7-day weather, not historical
→ Best destinations in January — all destinations ranked by January 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.