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SunnyDays

ERA5 almanac comparison — 8 years of real data

Bryce Canyon vs San Juan Islands: weather in September

Bryce Canyon edges out San Juan Islands for sun in September: 32% clear historically versus 6% (8-year ERA5 average, a 26-point gap). Both are viable — Bryce Canyon is the safer bet.

What you are reading: 8-year historical averages, not a forecast. Either destination can still surprise you this specific September. For this week’s actual forecast, each destination links to its live page below.

Bryce Canyon

UT

Clear days, September
32%
Sample size
n=240 days
Avg high
71°F
Early September (1st–15th)
41%
Late September (16th–end)
22%

San Juan Islands

WA

Clear days, September
6%
Sample size
n=240 days
Avg high
64°F
Early September (1st–15th)
10%
Late September (16th–end)
2%

Compare Bryce Canyon vs San Juan Islands 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.