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SunnyDays

ERA5 almanac — 8 years of real data

Aruba in December

Aruba in December: 55% of days see measurable rain, 84°F average high, 12% of days historically clear (n=248, ERA5 2018–2025).

Aruba in December is historically a poor month for sun: only 12% of days clear across 8 years (n=248, avg high 84°F). May is the clearest month for Aruba 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 Aruba 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 Aruba 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		 13% n=120 84°F
Late December
16th–end		 12% n=128 84°F
Full month average 12% n=248 84°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 Aruba 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		 100% n=128
Full month average 100% n=248
11.0 h median sunshine per day 100% of days exceed 8 h sunshine 55% of days see ≥ 1 mm rain — rain is not hidden
Comparison (old vs new): WMO-code “clear” bar: 12%. Sunshine-based “warm & sunny”: 100%. The 88-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

Aruba is a poor choice for sun in December: just 12% of days clear historically (n=248). May is the historically strongest month for sun here. The 8-year record is consistent — this is not a fluke bad stretch.

→ See all destinations in May — historically the best month for sun in Aruba.

Every month in Aruba

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

Historical clear-sky % for Aruba, all months, ERA5 2018–2025.
Month % Clear Sample (n)
January 24% n=248 All destinations →
February 22% n=226 All destinations →
March 33% n=248 All destinations →
April 33% n=240 All destinations →
May 39% n=248 All destinations →
June 30% n=240 All destinations →
July 22% n=248 All destinations →
August 24% n=248 All destinations →
September 32% n=240 All destinations →
October 14% n=248 All destinations →
November 6% n=240 All destinations →
December ← this page 12% n=248 All destinations →

Frequently asked

Does it rain in Aruba in December?

Yes, frequently. In Aruba, 55% of days in December 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 Aruba good for sun in December?

Not usually. Aruba is historically overcast in December: only 12% of days are clear (avg high 84°F, n=248 days, ERA5 2018–2025). May is historically far better for sun here.

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.