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SunnyDays

ERA5 almanac — 8 years of real data

Orlando in September

Orlando in September is historically a poor month for sun: only 10% of days clear across 8 years (n=240, avg high 86°F). March is the clearest month for Orlando 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 Orlando 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 Orlando 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		 8% n=120 86°F
Late September
16th–end		 13% n=120 86°F
Full month average 10% 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 Orlando 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		 85% n=120
Late September
16th–end		 90% n=120
Full month average 88% n=240
10.6 h median sunshine per day 80% of days exceed 8 h sunshine 72% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 10%. Sunshine-based “warm & sunny”: 88%. The 78-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

Orlando is a poor choice for sun in September: just 10% of days clear historically (n=240). March is the historically strongest month for sun here. The 8-year record is consistent — this is not a fluke bad stretch.

→ See all destinations in March — historically the best month for sun in Orlando.

Every month in Orlando

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

Historical clear-sky % for Orlando, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 20% n=248 All destinations →
February 33% n=226 All destinations →
March 45% n=248 All destinations →
April 44% n=240 All destinations →
May 30% n=248 All destinations →
June 7% n=240 All destinations →
July 2% n=248 All destinations →
August 3% n=248 All destinations →
September ← this page 10% n=240 All destinations →
October 30% n=248 All destinations →
November 32% n=240 All destinations →
December 26% 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.