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SunnyDays

ERA5 almanac — 8 years of real data

Charlottesville in September

Charlottesville in September: 31% of days see measurable rain, 81°F average high, 46% of days historically clear (n=240, ERA5 2018–2025).

Charlottesville in September is a mixed month for sun: 46% of days historically clear (n=240, avg high 81°F). The outcome varies year to year — check the early/late split below. 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 Charlottesville 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 September

Clear-sky percentage for Charlottesville in September, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early September
1st–15th		 53% n=120 81°F
Late September
16th–end		 38% n=120 81°F
Full month average 46% n=240 81°F

Sunshine & warmth in September

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 Charlottesville in September. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early September
1st–15th		 88% n=120
Late September
16th–end		 62% n=120
Full month average 75% n=240
11.5 h median sunshine per day 72% 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: 46%. Sunshine-based “warm & sunny”: 75%. 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

Charlottesville in September is genuinely mixed: 46% of days historically clear (n=240), avg high 81°F — roughly even odds. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Charlottesville

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

Historical clear-sky % for Charlottesville, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 1% n=226 All destinations →
March 5% n=248 All destinations →
April 24% n=240 All destinations →
May 32% n=248 All destinations →
June 48% n=240 All destinations →
July 37% n=248 All destinations →
August 40% n=248 All destinations →
September ← this page 46% n=240 All destinations →
October 29% n=248 All destinations →
November 4% n=240 All destinations →
December 0% n=248 All destinations →

Frequently asked

Does it rain in Charlottesville in September?

Sometimes. Charlottesville sees measurable rain on 31% of days in September historically (n=240 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Charlottesville good for sun in September?

It's mixed. Charlottesville in September is clear on 46% of days historically (avg high 81°F, n=240 days, ERA5 2018–2025) — the outcome varies year to year.

How Charlottesville compares in September

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