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SunnyDays

ERA5 almanac — 8 years of real data

Cartagena in December

Cartagena in December: 26% of days see measurable rain, 88°F average high, 26% of days historically clear (n=248, ERA5 2018–2025).

Cartagena in December is historically a poor month for sun: only 26% of days clear across 8 years (n=248, avg high 88°F). February is the clearest month for Cartagena 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 Cartagena 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 December

Clear-sky percentage for Cartagena in December, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early December
1st–15th		 25% n=120 88°F
Late December
16th–end		 26% n=128 88°F
Full month average 26% n=248 88°F

Sunshine & warmth in December

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 Cartagena in December. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early December
1st–15th		 100% n=120
Late December
16th–end		 98% n=128
Full month average 99% n=248
11.2 h median sunshine per day 97% 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: 26%. Sunshine-based “warm & sunny”: 99%. The 73-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

Cartagena is mostly overcast in December historically: only 26% of days are clear across 8 years (n=248), avg high 88°F. If you want sun in Cartagena, 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 Cartagena.

Every month in Cartagena

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

Historical clear-sky % for Cartagena, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 51% n=248 All destinations →
February 56% n=226 All destinations →
March 35% n=248 All destinations →
April 10% n=240 All destinations →
May 5% n=248 All destinations →
June 4% n=240 All destinations →
July 4% n=248 All destinations →
August 3% n=248 All destinations →
September 1% n=240 All destinations →
October 1% n=248 All destinations →
November 4% n=240 All destinations →
December ← this page 26% n=248 All destinations →

Frequently asked

Does it rain in Cartagena in December?

Sometimes. Cartagena sees measurable rain on 26% of days in December historically (n=248 days, ERA5 2018–2025) — not frequent enough to plan around, but not negligible either.

Is Cartagena good for sun in December?

Not usually. Cartagena is historically overcast in December: only 26% of days are clear (avg high 88°F, n=248 days, ERA5 2018–2025). February is historically far better for sun here.

How Cartagena compares in December

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