Cool
Average highs are around 20°C, so pack for cooler days.
September verdict
Poor for holiday weather
Average highs are around 20°C, so pack for cooler days. Sunshine averages 6.4h per day, enough for a balanced month. Rainfall averages 94mm, so some wet days are possible.
Monthly averages
Temp
20°C
Rain
94mm
Sun
6.4h
Sea
18°C
Weather score
37
Poor
Cool
Average highs are around 20°C, so pack for cooler days.
Showers
Rainfall averages 94mm, so some wet days are possible.
Some sun
Sunshine averages 6.4h per day, enough for a balanced month.
Cool sea
Sea temperatures average 18°C, so the water can feel cool.
Map
Compare Iron Mountain, Michigan, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
September20°C average high
September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.
Warmest monthsMay to September
This stretch sets the upper range for average daytime heat.
September94mm average rain
September is one of Iron Mountain's wettest months, so rain is likely to be a major planning factor.
Driest monthsJanuary to March and November to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
September6.4 hours average sun
September sits close to Iron Mountain's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
September18°C average sea
September sits in the warmer sea-temperature season, usually making swimming easier to enjoy.
Warmest seaJuly to September
Sea temperatures are usually near 19°C in this stretch, so swimming comfort is at its strongest.
September37 weather score
September scores below Iron Mountain's yearly average, so the weather trade-offs are more noticeable.
Best weather monthsJuly to August
These months have the strongest weather score in the monthly averages.