Skip to main content
SunnyDays

ERA5 almanac — 8 years of real data

Mérida in October

Mérida in October: 51% of days see measurable rain, 89°F average high, 20% of days historically clear (n=248, ERA5 2018–2025).

Mérida in October is historically a poor month for sun: only 20% of days clear across 8 years (n=248, avg high 89°F). March is the clearest month for Mérida 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 Mérida 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 Mérida 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		 12% n=120 89°F
Late October
16th–end		 28% n=128 89°F
Full month average 20% n=248 89°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 Mérida 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		 89% n=120
Late October
16th–end		 95% n=128
Full month average 92% n=248
11.0 h median sunshine per day 87% of days exceed 8 h sunshine 51% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 20%. Sunshine-based “warm & sunny”: 92%. The 72-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

Mérida is mostly overcast in October historically: only 20% of days are clear across 8 years (n=248), avg high 89°F. If you want sun in Mérida, March is historically much better. Most visitors this month will see more clouds than sun.

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

Every month in Mérida

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

Historical clear-sky % for Mérida, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 55% n=248 All destinations →
February 61% n=226 All destinations →
March 74% n=248 All destinations →
April 68% n=240 All destinations →
May 47% n=248 All destinations →
June 20% n=240 All destinations →
July 20% n=248 All destinations →
August 13% n=248 All destinations →
September 8% n=240 All destinations →
October ← this page 20% n=248 All destinations →
November 38% n=240 All destinations →
December 53% n=248 All destinations →

Frequently asked

Does it rain in Mérida in October?

Yes, frequently. In Mérida, 51% 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 Mérida good for sun in October?

Not usually. Mérida is historically overcast in October: only 20% of days are clear (avg high 89°F, n=248 days, ERA5 2018–2025). March is historically far better for sun here.

How Mérida compares in October

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