September weather forecastEvanston, WY
September
Weather in September
September in Evanston marks the arrival of fall, with a noticeable drop in temperature compared to August's highs. The weather changes remarkably, with snowfall figures rising back to 0.91" (23mm) from August's nearly non-existent totals. September ushers in fall's colourful spectacle, with leaves changing from green to shades of gold, and orange, providing photogenic landscapes. September's weather heralds the onset of cooler days, with October expected to introduce much colder temperatures.Temperature
In Evanston, entering September brings a temperature decrement, reducing from August's moderately hot 77.5°F (25.3°C) to an agreeable 68.5°F (20.3°C). A marked drop from daytime peak temperatures to an average low-temperature of 45°F (7.2°C) is observed during the nights in September.Humidity
In Evanston, the average relative humidity in September is 44%.Rainfall
In Evanston, Wyoming, in September, it is raining for 8 days, with typically 0.71" (18mm) of accumulated precipitation. Throughout the year, there are 94.2 rainfall days, and 11.5" (292mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1.1 snowfall days, it receives 0.91" (23mm) of snow. In Evanston, during the entire year, snow falls for 99.3 days and aggregates up to 56.22" (1428mm) of snow.Daylight
In Evanston, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:51 am and sunset at 7:56 pm. On the last day of September, sunrise is at 7:20 am and sunset at 7:06 pm MDT.
Sunshine
In September, the average sunshine is 10.3h.UV index
In Evanston, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 4 during September translates into the following recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. The solar radiation around mid-day is intense; avoid the Sun and stay safe. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Evanston, WY
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is December (26.4°F).
- Average low temperature in September: 45°F
The month with the highest average low temperature is July (51.6°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).
Average pressure in September
Evanston, WY
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Evanston, WY
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is April (8.2mph).
The calmest month (with the lowest average wind speed) is July (6.7mph).
Average humidity in September
Evanston, WY
- Average humidity in September: 44%
The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Evanston, WY
- Average rainfall in September: 0.71"
The wettest months (with the highest rainfall) are April and May (1.38").
The driest month (with the least rainfall) is August (0.51").
Average rainfall days in September
Evanston, WY
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is May (11.9 days).
The month with the least rainy days is February (5.5 days).
Average snowfall in September
Evanston, WY
- Average snowfall in September: 0.91"
The month with the highest snowfall is March (10").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Evanston, WY
- Average snowfall days in September: 1.1 days
The month with the highest number of snowfall days is February (16.3 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Evanston, WY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 10h and 18min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 48min).
Average sunshine days in September
Evanston, WY
- Average sunshine days in September: 17 days
The month with the most sunshine days is June (19.5 days).
The month with the least sunshine days is April (10.8 days).
Average UV index in September
Evanston, WY
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are November and December (UV index 1).
Average cloud cover in September
Evanston, WY
- Average cloud cover in September: 13
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 10).
Average visibility in September
Evanston, WY
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
