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SunnyDays

ERA5 almanac — 8 years of real data

Memphis in September

Memphis in September: 26% of days see measurable rain, 85°F average high, 58% of days historically clear (n=240, ERA5 2018–2025).

Memphis in September is a mixed month for sun: 58% of days historically clear (n=240, avg high 85°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 Memphis 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 Memphis 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		 57% n=120 85°F
Late September
16th–end		 60% n=120 85°F
Full month average 58% n=240 85°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 Memphis 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		 90% n=120
Late September
16th–end		 86% n=120
Full month average 88% n=240
11.8 h median sunshine per day 82% of days exceed 8 h sunshine 26% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 58%. Sunshine-based “warm & sunny”: 88%. The 30-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

Memphis in September is genuinely mixed: 58% of days historically clear (n=240), avg high 85°F — more clear than cloudy. The outcome varies year to year; don't book if you need guaranteed sun.

Every month in Memphis

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

Historical clear-sky % for Memphis, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 0% n=248 All destinations →
February 1% n=226 All destinations →
March 8% n=248 All destinations →
April 20% n=240 All destinations →
May 32% n=248 All destinations →
June 38% n=240 All destinations →
July 33% n=248 All destinations →
August 42% n=248 All destinations →
September ← this page 58% n=240 All destinations →
October 45% n=248 All destinations →
November 8% n=240 All destinations →
December 1% n=248 All destinations →

Frequently asked

Does it rain in Memphis in September?

Sometimes. Memphis sees measurable rain on 26% of days in September historically (n=240 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Memphis good for sun in September?

It's mixed. Memphis in September is clear on 58% of days historically (avg high 85°F, n=240 days, ERA5 2018–2025) — the outcome varies year to year.

How Memphis compares in September

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