ERA5 almanac comparison — 8 years of real data
Phoenix vs Tulum: weather in January
Tulum edges out Phoenix for sun in January: 23% clear historically versus 17% (8-year ERA5 average, a 6-point gap). Tulum also sees measurably more rain than Phoenix this month (50% vs 12% of days). Both are viable — Tulum is the safer bet.
Phoenix
AZ
- Clear days, January
- 17%
- Sample size
- n=248 days
- Avg high
- 66°F
- Early January (1st–15th)
- 13%
- Late January (16th–end)
- 20%
- Rain frequency
- 12% of days
Tulum
Mexico
- Clear days, January
- 23%
- Sample size
- n=248 days
- Avg high
- 80°F
- Early January (1st–15th)
- 25%
- Late January (16th–end)
- 21%
- Rain frequency
- 50% of days
Frequently asked
Is Phoenix or Tulum warmer in January?
Tulum runs warmer by day in January. Phoenix averages highs of 66°F (highs n=248 days); Tulum averages highs of 80°F (highs n=248 days) (ERA5 2018–2025). Historical averages, not a forecast.
Does it rain more in Phoenix or Tulum in January?
Tulum is measurably wetter than Phoenix. Days with measurable rain: Phoenix 12%, Tulum 50% (n=248 and n=248 days). ERA5 2018–2025; historical, not a forecast.
Which is sunnier in January, Phoenix or Tulum?
Tulum edges out Phoenix for sun in January: 23% clear historically versus 17% (8-year ERA5 average, a 6-point gap). Tulum also sees measurably more rain than Phoenix this month (50% vs 12% of days). Both are viable — Tulum is the safer bet.
Compare Phoenix vs Tulum 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.