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SunnyDays

ERA5 almanac — 8 years of real data

Mexico City in October

Mexico City in October: 50% of days see measurable rain, 74°F average high, 20% of days historically clear (n=248, ERA5 2018–2025).

Mexico City in October is historically a poor month for sun: only 20% of days clear across 8 years (n=248, avg high 74°F). February is the clearest month for Mexico City 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 Mexico City 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 October

Clear-sky percentage for Mexico City in October, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early October
1st–15th		 10% n=120 74°F
Late October
16th–end		 29% n=128 74°F
Full month average 20% n=248 74°F

Sunshine & warmth in October

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 Mexico City in October. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early October
1st–15th		 55% n=120
Late October
16th–end		 62% n=128
Full month average 59% n=248
10.7 h median sunshine per day 88% of days exceed 8 h sunshine 50% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 20%. Sunshine-based “warm & sunny”: 59%. The 39-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

Mexico City is mostly overcast in October historically: only 20% of days are clear across 8 years (n=248), avg high 74°F. If you want sun in Mexico City, February is historically much better. Most visitors this month will see more clouds than sun.

→ See all destinations in February — historically the best month for sun in Mexico City.

Every month in Mexico City

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

Historical clear-sky % for Mexico City, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 52% n=248 All destinations →
February 71% n=226 All destinations →
March 71% n=248 All destinations →
April 51% n=240 All destinations →
May 33% n=248 All destinations →
June 18% n=240 All destinations →
July 1% n=248 All destinations →
August 2% n=248 All destinations →
September 4% n=240 All destinations →
October ← this page 20% n=248 All destinations →
November 52% n=240 All destinations →
December 50% n=248 All destinations →

Frequently asked

Does it rain in Mexico City in October?

Yes, frequently. In Mexico City, 50% of days in October see measurable rain, based on 8 years of ERA5 historical data (n=248 days, 2018–2025). This is a historical average, not a forecast.

Is Mexico City good for sun in October?

Not usually. Mexico City is historically overcast in October: only 20% of days are clear (avg high 74°F, n=248 days, ERA5 2018–2025). February is historically far better for sun here.

How Mexico City compares in October

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