Colorado, United States in September

September20°C average high

September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.

Warmest monthsJune to September

This stretch sets the upper range for average daytime heat.

September34mm average rain

September sits near Colorado's yearly rainfall average, so rain is a normal planning factor rather than an outlier.

Driest monthsJanuary to June and September to December

This is the drier part of the year, when outdoor plans usually need less weather flexibility.

September8.7 hours average sun

September sits close to Colorado'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.

September45 weather score

September scores below Colorado's yearly average, so the weather trade-offs are more noticeable.

Best weather monthsJune to August

These months have the strongest weather score in the monthly averages.