Avg High
Denver in September
Verdict
In Denver, September has a distinct autumn feel. As the season moves along, temperatures are dropping quickly. You can usually expect a warm month that feels manageable day to day. Breezes can be part of the character, especially in exposed spots.
It suits travellers who want straightforward weather for sightseeing and day trips. Lookouts and coastal walks can feel sharper when the wind is up.
Avg Low
Rain
Daylight
12h
What to expect
- Daytime feel - Summer-like warmth where evenings can feel like a different season. It can feel cooler than the thermometer suggests.
- Rain pattern - A mix of dry and wet days. Rain is usually intermittent rather than relentless. Keep a light rain layer handy.
- Sun & UV - High UV at midday. Cloud cover doesn't always mean low UV, so still protect your skin. Shade breaks feel genuinely worthwhile.
- Exposure - Light air, and gusts can catch you in exposed spots. A light outer layer helps when you’re in the shade.
September in context
How it compares to the rest of the year in Denver.
Hottest (avg)
#4 / 12
Wettest (avg)
#8 / 12
Daylight Hours
#6 / 12
Windiest (avg)
#10 / 12
Highest UV
#6 / 12
Most Humid
#11 / 12
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight
- 12.4 hours
- UV index (max)
- 7
- Typical sun hours
- 05:41 – 18:07
Rain & Snow
- Total
-
- Rainy days
- 8
- Cloud cover
- 35%
- Snowfall
-
Humidity & Wind
- Humidity (avg)
- 49%
- Wind (avg)
-
- Wind (max gusts)
-
Frequently asked questions
Is September a good time to visit Denver?
Typical September days in Denver reach highs of 25°C (77°F) with nights around 10°C (50°F). It usually feels warm by day and cool after dark. Overall, September sits in the middle of the Denver climate range.
What are temperatures like in September?
In September, you can usually expect highs of 25°C (77°F) and lows near 10°C (50°F). That means warm days and cool nights, so pack layers you can add or remove.
How much does it rain in September?
Rainfall in September averages 34 mm (1.3 in) across roughly 8 days. Overall it is a moderately wet time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 05:41 and sunset near 18:07. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 7). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 8 km/h (5 mph), with gusts on the windiest days reaching about 44 km/h (27 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.