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SunnyDays

ERA5 almanac comparison — 8 years of real data

Mexico City vs Outer Banks: weather in September

Outer Banks is the clear winner for sun in September: 40% of days historically clear versus just 4% in Mexico City — a 36-point gap across 8 years of ERA5 data. Mexico City also sees measurably more rain than Outer Banks this month (84% vs 36% of days). This isn't close.

What you are reading: 8-year historical averages, not a forecast. Either destination can still surprise you this specific September. For the actual forecast right now, each destination links to its live page below.

Mexico City

Mexico

Clear days, September
4%
Sample size
n=240 days
Avg high
73°F
Early September (1st–15th)
2%
Late September (16th–end)
6%
Rain frequency
84% of days

Outer Banks

NC

Clear days, September
40%
Sample size
n=240 days
Avg high
78°F
Early September (1st–15th)
38%
Late September (16th–end)
43%
Rain frequency
36% of days

Frequently asked

Is Mexico City or Outer Banks warmer in September?

Outer Banks runs warmer by day in September. Mexico City averages highs of 73°F (highs n=240 days); Outer Banks averages highs of 78°F (highs n=240 days) (ERA5 2018–2025). Historical averages, not a forecast.

Does it rain more in Mexico City or Outer Banks in September?

Mexico City is measurably wetter than Outer Banks. Days with measurable rain: Mexico City 84%, Outer Banks 36% (n=240 and n=240 days). ERA5 2018–2025; historical, not a forecast.

Which is sunnier in September, Mexico City or Outer Banks?

Outer Banks is the clear winner for sun in September: 40% of days historically clear versus just 4% in Mexico City — a 36-point gap across 8 years of ERA5 data. Mexico City also sees measurably more rain than Outer Banks this month (84% vs 36% of days). This isn't close.

Compare Mexico City vs Outer Banks in another month

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 forecast for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.