September weather forecast
Dubuque, IA

Share
A small railway line in Dubuque, Iowa, set on a hilly and scenic greenery spot overlooking the brown buildings in the rest of the city
A small railway line in Dubuque, Iowa, set on a hilly and scenic greenery spot overlooking the brown buildings in the rest of the city

Weather in September

September brings a soothing transition from summer to fall in Dubuque, Iowa. The temperatures witness a moderate drop to 72.5°F (22.5°C) from the August highs, making it an idyllic month for exploring the city and its surroundings. The decreasing daylight hours and changing hues of leaves signal the impending arrival of autumn. Despite the rainfall of 2.6" (66mm), it undoubtedly remains an enjoyable time to relish the outdoor activities. The taste of fall and warm weather make this month a unique time to experience Dubuque's beauty.

Temperature

The arrival of September correlates with a minor temperature reduction, down from August's warm 78.6°F (25.9°C) to a pleasant 72.5°F (22.5°C). An average nighttime temperature of 53.2°F (11.8°C) is observed during September.

Humidity

The average relative humidity in September is 80%.

Rainfall

In Dubuque, in September, it is raining for 11.4 days, with typically 2.6" (66mm) of accumulated precipitation. In Dubuque, during the entire year, the rain falls for 135.3 days and collects up to 27.4" (696mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:36 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:45 pm CDT.

Sunshine

In September, the average sunshine is 8.9h.

UV index

In Dubuque, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.
Note: In September, the maximum UV index of 4 translates into these guidelines:
Take necessary precautions - Protection from skin and eye injury is mandatory. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

Frequently asked questions

What are the temperatures in September?

In September, in Dubuque, the average high-temperature is 72.5°F (22.5°C), and the average low-temperature is 53.2°F (11.8°C).

What is the average humidity in September?

In Dubuque, the average relative humidity in September is 80%.

How many days does it rain in September?

In Dubuque, in September, it is raining for 11.4 days, with typically 2.6" (66mm) of accumulated precipitation.

When it does not snow?

May through September are months without snowfall.

Does it snow in September?

In Dubuque, Iowa, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

The average day length in September is 12h and 28min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:28 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:45 pm CDT.

How long on average sun shines in September?

In Dubuque, the average sunshine duration in September is 8.9h.

How high is the UV index in September?

In Dubuque, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Dubuque, IA

Average temperature in September - Dubuque, IA
  • Average high temperature in September: 72.5°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (25°F).

  • Average low temperature in September: 53.2°F

The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).

Average pressure in September
Dubuque, IA

Average pressure in September - Dubuque, IA
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in September
Dubuque, IA

Average wind speed in September - Dubuque, IA
  • Average wind speed in September: 7.8mph

The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity in September
Dubuque, IA

Average humidity in September - Dubuque, IA
  • Average humidity in September: 80%

The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is October (76%).

Average rainfall in September
Dubuque, IA

Average rainfall in September - Dubuque, IA
  • Average rainfall in September: 2.6"

The wettest months (with the highest rainfall) are May and June (3.7").
The driest months (with the least rainfall) are January and February (1.14").

Average rainfall days in September
Dubuque, IA

Average rainfall days in September - Dubuque, IA
  • Average rainfall days in September: 11.4 days

The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (4.4 days).

Average snowfall in September
Dubuque, IA

Average snowfall in September - Dubuque, IA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (4.88").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Dubuque, IA

Average snowfall days in September - Dubuque, IA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Dubuque, IA

Average daylight in September / Average sunshine in September - Dubuque, IA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in September: 8h and 5min

The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

Average sunshine days in September
Dubuque, IA

Average sunshine days in September - Dubuque, IA
  • Average sunshine days in September: 17.2 days

The months with the most sunshine days are November and December (17.5 days).
The month with the least sunshine days is June (10.3 days).

Average UV index in September
Dubuque, IA

Average UV index in September - Dubuque, IA
  • Average UV index in September: 4

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).

Average cloud cover in September
Dubuque, IA

Average cloud cover in September - Dubuque, IA
  • Average cloud cover in September: 33

The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in September
Dubuque, IA

Average visibility in September - Dubuque, IA
  • Average visibility in September: 6mi

The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).

Dubuque, Iowa, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location