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SunnyDays

ERA5 almanac comparison — 8 years of real data

Bar Harbor vs St. Augustine: weather in September

Essentially a tie in September: Bar Harbor is 16% clear historically, St. Augustine is 17% clear (8-year ERA5 average) — within the noise. Avg high 68°F vs 83°F. St. Augustine also sees measurably more rain than Bar Harbor this month (64% vs 27% of days). Pick based on flight time or price, not weather — the weather won't decide this one for you.

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.

Bar Harbor

ME

Clear days, September
16%
Sample size
n=240 days
Avg high
68°F
Early September (1st–15th)
22%
Late September (16th–end)
9%
Rain frequency
27% of days

St. Augustine

FL

Clear days, September
17%
Sample size
n=240 days
Avg high
83°F
Early September (1st–15th)
11%
Late September (16th–end)
23%
Rain frequency
64% of days
See this week’s live forecast →

Compare Bar Harbor vs St. Augustine 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.