September weather forecast
Wyoming, USA

September marks the onset of autumn in Wyoming, bringing with it a notable shift in climate and scenery. Average low temperatures begin to drop, generally ranging from 40°F (4.4°C) to 50°F (10°C), while average high temperatures in the plains may reach up to 75°F (23.9°C). In the highlands, expect temperatures to peak between 60°F (15.6°C) and 70°F (21.1°C). The month also sees a reduction in precipitation, although the range varies from 8" (203mm) in the lowlands to 15" (381mm) in the higher elevations.

Relative to August, September experiences shorter days and cooler temperatures, signaling the transition into fall. Winds maintain their presence but are generally not as intense as in the summer months. Thunderstorm activity decreases considerably, making room for more stable weather patterns. September is especially popular for its scenic appeal, as foliage in the high country starts to change color, offering a vibrant landscape. The tourist season continues but at a slower pace, making it an excellent time for visitors who prefer fewer crowds while still enjoying good weather and outdoor activities.

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• Cheyenne - September »
  The advent of September in Cheyenne brings a slight shift in average high-temperature, moving from a moderately hot 81.1°F (27.3°C) in August to a still warm 73.8°F (23.2°C). In September, the average high-temperature and low-temperature in Cheyenne, Wyoming, are 73.8°F (23.2°C) and 52.3°F (11.3°C) respectively.
• Casper - September »
  The months with the least rainfall in Casper, Wyoming, are January, August and September Rain falls for 7.6 days and accumulates 0.43" (11mm) of rain. The months with the least rainfall in Casper are January, August and September Rain falls for 7.6 days and accumulates 0.43" (11mm) of rain.
• Laramie - September »
  In Laramie, during September, the rain falls for 9.9 days and regularly aggregates up to 0.98" (25mm) of precipitation. In Laramie, during September, the rain falls for 9.9 days and regularly aggregates up to 0.98" (25mm) of precipitation.
• Gillette - September »
  In Gillette, during September, the rain falls for 10.2 days and regularly aggregates up to 1.02" (26mm) of precipitation. On the first day of September in Gillette, sunrise is at 6:25 am and sunset at 7:37 pm.
• Rock Springs - September »
  In Rock Springs, during September, the rain falls for 7.2 days and regularly aggregates up to 0.63" (16mm) of precipitation. In Rock Springs, during September, the rain falls for 7.2 days and regularly aggregates up to 0.63" (16mm) of precipitation.
• Sheridan - September »
  In Sheridan in September, it is raining for 12.5 days, with typically 1.42" (36mm) of accumulated precipitation. On the first day of September in Sheridan sunrise is at 6:31 am and sunset at 7:44 pm.
• Green River - September »
  In Green River in September, during 7.2 rainfall days, 0.63" (16mm) of precipitation is typically accumulated. September temperatures in Green River vary between a high-temperature of 70.3°F (21.3°C) and a low-temperature of 51.3°F (10.7°C).
• Evanston - September »
  In September, in Evanston the rain falls for 8 days. On the first day of September in Evanston, sunrise is at 6:51 am and sunset at 7:56 pm.
• Riverton - September »
  On the first day of September in Riverton, sunrise is at 6:38 am and sunset at 7:47 pm. In Riverton, during September, the rain falls for 6 days and regularly aggregates up to 0.55" (14mm) of precipitation.
• Jackson - September »
  In Jackson in September, during 3.3 snowfall days, 5.12" (130mm) of snow is typically accumulated. In Jackson in September, during 10.8 rainfall days, 1.77" (45mm) of precipitation is typically accumulated.
• Cody - September »
  On the first day of September in Cody sunrise is at 6:39 am and sunset at 7:52 pm. In Cody, during September, the rain falls for 6.5 days and regularly aggregates up to 0.59" (15mm) of precipitation.
• Rawlins - September »
  Fall claims Rawlins in September, leading to comfortably warm days and cool, breezy evenings. In Rawlins, during September, the rain falls for 7 days and regularly aggregates up to 0.47" (12mm) of precipitation.