Star Valley September Weather Review-Rains Arrive!

Star Valley September Weather Review-Rains Arrive!

The month of September began with a continuation of the very dry summer across much of Western Wyoming.  After virtually 4 weeks without hardly a drop of rain, a major weather pattern change took place a week into the month.


From the 7th of the month there were several periods of showers, with a major precipitation event occurring the last days of the month

Storm Rainfall Summary September 27-29 2019


Precipitation totals for the month were substantial throughout much of western Wyoming and Southeast Idaho.  The map below is the reported amounts around the Star Valley area. At least 3 inches was measured throughout the valley with the greatest around 5 inches in the Star Valley Ranch area.

Total rainfall for September 2019

Following are the daily graphs of the rainfall for both the Afton and Bedford 3SE stations.

Afton daily precipitation September 2019
Bedford 3SE daily precipitation September 2019

The first week of September was dry and very warm.  The highest temperature for the month was on the 5th when Etna Elementary School hit 94.  Thayne Elementary had a high of 90 on the 1st. The high of 88 on the 2nd tied the record maximum for the date at Afton.

Below freezing occurred at all reporting stations in Star Valley on the 30th ranging from a low of 21 at Smoot, 22 at Double L Ranch to 27 at Star Valley Ranch.

Following are the daily temperatures at Afton and Bedford 3SE.

Afton Daily temperatures September 2019
Daily temperatures Bedford 3SE September 2019

Much of western Wyoming experienced well above normal precipitation for the month.

Precipitation departure from normal September 2019

Precipitation amounts were greatest across Star Valley and the area around Yellowstone NP.

Total precipitation September 2019

While western Wyoming ended up with near normal temperatures for the month, further east was quite warm.

Average temperature departure from normal September 2019