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SunnyDays

ERA5 almanac — 8 years of real data

Cartagena in January

Cartagena in January: 15% of days see measurable rain, 89°F average high, 51% of days historically clear (n=248, ERA5 2018–2025).

Cartagena in January is a mixed month for sun: 51% of days historically clear (n=248, avg high 89°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 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 January

Clear-sky percentage for Cartagena in January, split by half-month. “n” is the number of days sampled across 8 years (2018–2025).
Period % Clear days Sample (n) Avg high
Early January
1st–15th		 40% n=120 89°F
Late January
16th–end		 62% n=128 89°F
Full month average 51% n=248 89°F

Sunshine & warmth in January

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 January. Primary: % of days ≥ 72°F with > 6 h of sunshine.
Period Warm & sunny (≥72°F, >6 h sun) Sample (n)
Early January
1st–15th		 99% n=120
Late January
16th–end		 100% n=128
Full month average 100% n=248
11.2 h median sunshine per day 99% of days exceed 8 h sunshine 15% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 51%. Sunshine-based “warm & sunny”: 100%. The 49-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 in January is genuinely mixed: 51% of days historically clear (n=248), avg high 89°F — roughly even odds. The two halves differ materially (40% early, 62% late) — favour the late half of the month. The outcome varies year to year; don't book if you need guaranteed sun.

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 ← this page 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 26% n=248 All destinations →

Frequently asked

Does it rain in Cartagena in January?

Rarely. Only 15% of days in Cartagena see measurable rain in January, based on 8 years of ERA5 historical data (n=248 days, 2018–2025). This is a historical average, not a forecast.

Is Cartagena good for sun in January?

It's mixed. Cartagena in January is clear on 51% of days historically (avg high 89°F, n=248 days, ERA5 2018–2025) — the outcome varies year to year.

How Cartagena compares in January

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.