Normal weather for West Yellowstone in September
It's pleasantly warm in September in West Yellowstone with an average temperature of 19°C. Temperatures this month range from a low of 11°C to a high of 23°C. At night, you can expect temperatures between -6°C and 5°C.
In September, there is an average of 65 mm of precipitation, spread over 8 days. Of the total precipitation, about 4,1 cm falls as snow in September. The wind speed is around 4 Bft, mostly coming from the Southwest.
West Yellowstone in September |
London | ||
|---|---|---|---|
 Average Temperature |
19°C | 20°C | |
 High Temp |
23°C | 22°C | |
| Low Temp |
11°C | 17°C | |
 Total Precipitation |
65 mm | 44 mm | |
| Rainy Days |
8 days | 8 days | |
 Total Snowfall |
4,1 cm | 0 cm | |
| Snowy Days |
3 days | 0 days | |
Start of September
The month of September starts in West Yellowstone with mild temperatures, averaging around 21°C during the day and nights close to 1°C. There’s little chance of precipitation. The weather is mostly sunny and dry.
Since temperatures can differ between day and night, it’s a good idea to dress in layers. During the day, a shirt, maybe a light cardigan, and light trousers will do. For the evening and morning, we recommend a thick coat, jumper, and long trousers.
Mid-September
By mid-September, the average daytime temperature drops to around 19°C, with nights close to 0°C. There might be a few showers during this period, but plenty of dry days with sunshine too.
Temperatures vary between day and night, so it’s smart to wear layers. During the day, a shirt, maybe a light cardigan, and light trousers will do. For the evening and morning, we recommend a thick coat, jumper, and long trousers.
End of September
By the end of September, the average daytime temperature in West Yellowstone will be around 17°C, with nights close to 2°C. A shower might show up, but overall the weather will be dry and sunny.
As it gets cooler in the evening, it’s best to wear layers. During the day, go for a light coat, jumper or cardigan, and long trousers. For the evening and morning, we recommend a thick coat, jumper, and long trousers.
Discover cheap trips to West Yellowstone 
UV index
The UV index is a maximum of 8 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Temperature records for West Yellowstone in September
With 31°C, West Yellowstone hit the highest temperature in the last 10 years in September 2022. The lowest daytime temperature in this month was 2°C in 2019. The extreme night temperatures ranged from a low of -12°C to a high of 12°C.
Check out the climate of West Yellowstone for all months and discover the best travel time
August
Plan your next holiday
Don’t miss the best holiday deals for West Yellowstone and see what our partners have for you.
Daily Temperature in September in West Yellowstone
This chart shows the average daily temperatures, both day and night, for each day in September in West Yellowstone, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in West Yellowstone
The chart below shows the average daily precipitation in September for West Yellowstone, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 8 days of rain in West Yellowstone.
Daily Snowfall in September in West Yellowstone
This chart shows the average daily snowfall in September in West Yellowstone, measured in centimetres. The bottom of the chart shows the days of the month. The data is based on historical measurements and gives an idea of the average snowfall in September.
Daily UV Index in September in West Yellowstone
This chart shows the average daily UV index in September in West Yellowstone, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in West Yellowstone Over the Years
This chart shows the average temperature in September in West Yellowstone, measured in degrees Celsius, over the past years.
Total Precipitation in September in West Yellowstone Over the Years
This chart shows the average precipitation in September in West Yellowstone, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Snowfall in September in West Yellowstone per year
This chart shows the average snowfall in September in West Yellowstone, measured in centimetres, over the past years.
Daily climate in September for West Yellowstone
Click on a specific day in September for detailed info on the typical weather on that day in West Yellowstone. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in West Yellowstone
Have you been to West Yellowstone in September?
Share your weather experience in September in West Yellowstone.
Average Weather in West Yellowstone by Month
Click on a month below to see detailed weather info for West Yellowstone. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of West Yellowstone for all months at once
