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SunnyDays

ERA5 almanac — 8 years of real data

Sedona in September

Historically one of the better months to visit Sedona for sun: 74% of days are clear on average (n=240, avg high 86°F). Every percentage here is a historical average from 8 years of ERA5 data — 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 Sedona 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 Sedona 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		 71% n=120 86°F
Late September
16th–end		 76% n=120 86°F
Full month average 74% n=240 86°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 Sedona 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		 100% n=120
Late September
16th–end		 91% n=120
Full month average 96% n=240
11.9 h median sunshine per day 95% of days exceed 8 h sunshine 12% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 74%. Sunshine-based “warm & sunny”: 96%. The 22-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

Sedona clears solidly in September: 74% of days historically (n=240), avg high 86°F. Most trips here in September will find more sun than cloud.

Every month in Sedona

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

Historical clear-sky % for Sedona, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 1% n=226 All destinations →
March 6% n=248 All destinations →
April 54% n=240 All destinations →
May 82% n=248 All destinations →
June 88% n=240 All destinations →
July 64% n=248 All destinations →
August 57% n=248 All destinations →
September ← this page 74% n=240 All destinations →
October 50% n=248 All destinations →
November 14% 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.