ERA5 almanac comparison — 8 years of real data
Cayman Islands vs Phoenix: weather in December
Phoenix edges out Cayman Islands for sun in December: 22% clear historically versus 12% (8-year ERA5 average, a 10-point gap). Cayman Islands also sees measurably more rain than Phoenix this month (51% vs 13% of days). Both are viable — Phoenix is the safer bet.
Cayman Islands
Cayman Islands
- Clear days, December
- 12%
- Sample size
- n=248 days
- Avg high
- 82°F
- Early December (1st–15th)
- 13%
- Late December (16th–end)
- 12%
- Rain frequency
- 51% of days
Phoenix
AZ
- Clear days, December
- 22%
- Sample size
- n=248 days
- Avg high
- 67°F
- Early December (1st–15th)
- 25%
- Late December (16th–end)
- 20%
- Rain frequency
- 13% of days
Frequently asked
Is Cayman Islands or Phoenix warmer in December?
Cayman Islands runs warmer by day in December. Cayman Islands averages highs of 82°F (highs n=248 days); Phoenix averages highs of 67°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Cayman Islands or Phoenix in December?
Cayman Islands is measurably wetter than Phoenix. Days with measurable rain: Cayman Islands 51%, Phoenix 13% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in December, Cayman Islands or Phoenix?
Phoenix edges out Cayman Islands for sun in December: 22% clear historically versus 12% (8-year ERA5 average, a 10-point gap). Cayman Islands also sees measurably more rain than Phoenix this month (51% vs 13% of days). Both are viable — Phoenix is the safer bet.
Compare Cayman Islands vs Phoenix in another month
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 forecast for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.