September Weather in St. George, Utah - 2025

St. George is a famous winter destination in Southwestern Utah and is also the largest city in the area. This winter haven quickly developed into an ideal vacation spot for people of all ages as it featured world-class golf courses, the soothing beauty of nature, and culturally-rich historic buildings. St. George is a special treat for visitors and with the endless opportunities offered, it is almost impossible to not fall in love with the unique qualities of this remarkable valley.

Weather September 2025 in St. George Utah:

Generally, September in St. George will be quite hot, with an average temperature of around 89°F / 32°C. But due to the very dry air, it can feel somewhat uncomfortable for some people. You can expect around 3 rainy days, with on average 0.5 inches / 13 mm of rain during the month of September.
Resonable comfortable (very dry air) with high temperatures
Murray Foubister - CC BY-SA 2.0

September weather in St. George Utah

To get a good overview of the type of weather you can expect in September in St. George, we will look at the day and night temperature, and if September is comfortable or humid

Generally, September in St. George will be quite hot. Historical data shows that you can expect an average temperature of around 89°F / 32°C. But due to the very dry air, it can feel somewhat uncomfortable for some people. During the night, it will cool down to around 59°F / 15°C.

St. George does not have a lot of rainy days in September. You can expect around 3 rainy days, with on average 0.5 inches / 13 mm of rain during the whole month.

Average temperature
Wintersun Comfort grade and huricane risk

The forecast for September 2025 is based on historical data and are averages. They will give a good indication what you can expect, but the daily temperature and rain will fluctuate during the month.

September weather in St. George Utah in more detail

To get a better feeling for the type of weather, you can expect in September in St. George, we will look at the temperature, rain, wind, humidity, and sun and clouds

- What will the temperature be in St. George in September

Generally, you can expect in September an average temperature of 89°F / 32°C during the day and an average of 59°F / 15°C during the night. In September, during the warmest part of the afternoon, the temperature can often get as high as 98°F / 37°C, and at the end of the night, it can get as low as 44°F / 7°C.

When looking at the whole year, December is the coldest month, with an average temperature of around 53°F / 12°C. July is the hottest month, with an average temperature of around 100°F / 38°C. When comparing September with the temperature in the month before and after, this is slightly lower than August, which sees an average maximum temperature of around 96°F / 36°C. And more than October, which sees an average maximum temperature of around 78°F / 26°C.

Day and night temperature variation for St. George during the year.
Day and night temperature variation for St. George during the year.

But average temperatures only tell half of the story. It is also good to check the maximum and minimum temperatures. When looking at the whole year, July is the hottest month, with a temperature of around 107°F / 42°C. January and December are the coldest months, with a temperature of around 66°F / 19°C. When comparing September with the temperature in the month before and after, this is slightly lower than August, which sees an average maximum temperature of around 104°F / 40°C. And slightly more than October, which sees an average maximum temperature of around 89°F / 32°C.

In the following graph, you can see how many cold and hot days you can expect in St. George each month:

Day and night temperature variation for St. George during the year.
Day and night temperature variation for St. George during the year.

- Can you expect rain in September in St. George?

Generally, you can expect about 3 rain days in September, with on average 0.5 inches / 13 mm of rain.

When looking at the whole year, June is the dryest month, with an average rainfall of around 0.2 inches / 4 mmmm. February is the wettest month, with an average rainfall of around 1.3 inches / 32 mmmm. When comparing September with the month before and after, this is more than August, which sees around 0.3 inches / 7 mm of rain. And less than October, which sees around 0.8 inches / 20 mm of rain

Rain days for St. George during the year.
Rain days for St. George during the year.

If we look at the number of days with rain, June is the month with the least amount of rain days with an average of between 1 and 2 days. February is the month with the most rain days with around 6 days. When comparing September with the month before and after, this is almost equal to August, which sees an average of between 3 and 4 days of rain. And almost equal to October, which sees an average of between 3 and 4 days of rain

- Can you expect in September a lot of sunny days in St. George

Generally, you can expect around 23 sunny days in September and around 7 partly sunny days. The remaining days will be cloudy.

When looking at the whole year, June is the month with the highest number of sunny days, with around 24 sunny days. February is the month with the lowest number of sunny days, with around 12 sunny days. When comparing September with the number of sunny days in the month before and after, it is almost equal to August, with around 22 sunny days. And almost equal to October, with around 21 sunny days

The number of sunny, partly sunny, and cloudy days for St. George
The number of sunny, partly sunny, and cloudy days for St. George

We have looked at the sunny days in St. George. Let's also look at the cloudy or overcast days. December is the month with the highest number of cloudy days, with an average of between 5 and 6 cloudy days. June and September And are the months with the lowest number of cloudy days, with an average of between 0 and 1 cloudy days. When comparing September with the number of cloudy days in the month before and after, it is almost equal to August, with an average of between 0 and 1 cloudy days. And almost equal to October, with an average of between 1 and 2 cloudy days

- Will it be comfortable in September in St. George?

Generally, September in St. George will have very dry air, and can feel somewhat uncomfortable for some people. But will be fine for most..

We use the humidity and temperature in St. George to calculate the Wintersun Expert Comfort level for each month. The lower the Wintersun Expert Comfort level, the more comfortable it will be. Only for certain people, extremely dry air can feel slightly uncomfortable.

When looking at the whole year, November has the lowest humidity, with a Wintersun Expert comfort level of "comfortable" (very dry air). July has the highest humidity, with a Wintersun Expert comfort level of "comfortable" (very dry air). When comparing September with the month before and after, this is slightly less than August, which has a Wintersun Comfort level of "comfortable" (very dry air). And slightly more than October, which has a Wintersun Comfort level of "comfortable" (very dry air)

Wintersun Expert Humidity / Comfort level for St. George
Wintersun Expert Humidity / Comfort level for St. George

What to do in St. George Utah in September

St George has a variety of good options for visitors to explore. Some of them are mentioned below:

  • Snow Canyon State Park: Spending a day at this park is worth every second of your time. Picnicking, strolling, horseback riding, biking, and many other activities can be enjoyed amidst amazing breathtaking views.
  • Pioneer Park: The Park has a red rock landscape and is a great spot for outings. You can spend your afternoons participating in different activities like having a barbeque, a picnic, or simply taking a walk on the trails. 
  • Quail Creek State Park: The perfect place to spend your afternoons. The park provides you with many different facilities and you can actively participate in boating, jogging, and fishing.
  • St George Utah Temple: This 175-feet high historic building should definitely be on the top of your list for St. George sightseeing. The temple's grounds are adorned with beautiful trees and plants, rendering the place much more attractive.
  • Rosenbruch World Wildlife Museum: If you love wildlife, you will cherish the display in this museum where many taxidermic animals from around the world are presented like they are living in their natural habitat.
  • St. George Dinosaur Discovery Site at Johnson: This place contains a large collection of tracks of various creatures from the dinosaur-era. The exhibition center showcases the lifesize representation of dinosaurs responsible for these tracks.
  • St. George Art Museum: The museum offers multicultural and regional artworks from several eras, and hosts programs and events.
  • Tuacahn Center for the Arts: This place comprises of a scenic amphitheater, an indoor theater, and a shop. Countless visitors enjoy concerts and musicals at this place.
  • Red Hills Desert Garden: The garden is an utter delight for the nature lovers. It has around 5000 plants with bunches of flowers and also a stream laden with native fish species.

Is it humid in St. George Utah in September?

A lot of people ask interested in the humidity or relative humidity for St. George Utah in September. But the real question they want to ask is not about humidity but the amount of moisture in the air. Or better, about comfort. Will it be comfortable in September in St. George, or will high humidity make it uncomfortable.

To answer this question, we have to look at the dew point. Relative humidity can change a lot in St. George during the day and night, as it changes when the amount of moisture changes and, but also when the temperature changes. It is a lot less reliable for comfort. Where the dew point only varies with the amount of moisture in the air.

Looking at the dew point, we can see that for the month of September, you can expect that St. George will have very dry air, and can feel somewhat uncomfortable for some people. But will be fine for most..

November is the month with the most comfort. It will have very dry air, and can feel somewhat uncomfortable for some people. But will be fine for most.. July is the most uncomfortable month. It will have very dry air, and can feel somewhat uncomfortable for some people. But will be fine for most.. In the graph, you can see that there is a significant difference between the most comfortable and most uncomfortable months

Humidity level for St. George
Humidity level for St. George

Is September a good time to go to St. George Utah?

Trying to answer the question of whether September is a good time to go to St. George is not as easy as it first seems. Some people like colder weather, and others prefer a warmer climate. Some are fine with some humidity, and others are not. If your location has air conditioning, the night temperature is less important.

These are some examples. I will try to answer the question with a more generic person in mind. The more detailed information in this article should be enough to check further if this applies to you as well.

If we look at the average temperature for St. George in September, we can see that it will be too hot for a lot of visitors. In September, you can expect it to be quite hot, with an average temperature of around 89°F / 32°C. But due to the very dry air, it can feel somewhat uncomfortable for some people. During the night, it will be around 59°F / 15°C.

As the number of overcast days is not high, you can enjoy the sun with around 23 sunny days and 7 partly sunny days.

The last aspect we will look at is rain. You can expect around 3 rainy days, with on average 0.5 inches / 13 mm of rain during September. If it were more than five days, the location would be slightly less attractive for a shorter stay.

We have looked at the average day temperature, the night temperature, humidity, the number of overcast days, and the rain. We think that September in St. George Utah is not the most optimal destination. But that doesn't mean it is not a good time for you to go. As said before, each visitor has their own preferences when it comes to the weather.

Does it rain all day in St. George Utah in September?

In St. George, it does not rain all day in September. You can expect around 3 rainy days, with on average 0.5 inches / 13 mm of rain during the month.

Another way of looking at the rain is the number of sunny days. For St. George Utah, there are, on average 23 sunny days and 7 partly sunny days in September. That clearly shows that it is not raining all the time.

Is September the rainiest month in St. George Utah?

September is not the month with the most rainy days, and not the month with the most rain.

To answer what the rainiest month is in St. George, we will both look at the month with the most rain, and the month with the highest number of rainy days.

February is the month with the the highest number of rainiest days. On average, you can expect 6 days with rain. June is the month with the lowest number of rainy days, with aproximately 2 days.

February is the month with the most rain. This is not equal as the one with the most rainy days. On average, you can expect 1.3 inches / 32 mm of rain. June is the month with the least amount of rain. This is not the same month as the one with the lowest number of rainy days. You can expect approximately 0.2 inches / 4 mm of rain.

Is September the most sunniest month in St. George Utah?

September is not the month with the most sunny days, not the month with the most partly sunny days, and it is the month with the lowest number of overcast days.

To answer what the sunniest month is in St. George, we will of course look at the month with the most sunniest days, but also look at the month with the biggest number of days that are sunny or partly sunny.

June is the month with the highest number of sunny days. On average, you can expect 23 sunny days, and 7 partly suny days. February is the month with the lowest number of sunny days.

May and August are months with the highest number of sunny days and partly sunny days combined. While February is the month with the lowest number of sunny days and partly sunny days combined.

The last thing we will look at is the number of overcast days. June and September are the months with the lowest number of overcast days. While December is the month with the highest number of overcast days.

More information about St. George Utah

Weather in St. George Utah in other months

What to do in St. George Utah for each month

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