ERA5 almanac comparison — 8 years of real data
St. John, USVI vs Tulum: weather in June
St. John, USVI edges out Tulum for sun in June: 20% clear historically versus 6% (8-year ERA5 average, a 14-point gap). Tulum also sees measurably more rain than St. John, USVI this month (69% vs 40% of days). Both are viable — St. John, USVI is the safer bet.
What you are reading: 8-year historical averages, not a forecast.
Either destination can still surprise you this specific June. For this
week’s actual forecast, each destination links to its live page below.
St. John, USVI
VI
- Clear days, June
- 20%
- Sample size
- n=240 days
- Avg high
- 78°F
- Early June (1st–15th)
- 21%
- Late June (16th–end)
- 20%
- Rain frequency
- 40% of days
Tulum
MX
- Clear days, June
- 6%
- Sample size
- n=240 days
- Avg high
- 86°F
- Early June (1st–15th)
- 5%
- Late June (16th–end)
- 6%
- Rain frequency
- 69% of days
Compare St. John, USVI 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 7-day outlook for any destination is on its own page and may differ from the long-run average. Data from Open-Meteo.