Fall Weather Summary-Star Valley
With the official beginning of winter Saturday it is a good time to review Star Valley weather for the Fall of 2019. After what was the second very dry summer in a row, the weather pattern changed early in September. The following two charts show the Afton precipitation for the months of July/August 2019 when virtually no precipitation was reported, followed by September to mid December when around 8 inches was measured, more than 2 inches above normal.
Afton precipitation from July 1-August 31 2019 compared to normal
Afton precipitation from Sept 1-Dec 15 2019 compared to normal
Of greatest interest was the extraordinary cold of October 2019. For Afton the following records occurred where records go back almost 60 years. It was the all-time coldest October with a minimum of -7 on both the 30th and 31st, breaking the previous record of -2 set in 1991. In addition, Afton established new daily lows on the 11th, 12th, 28th and 30-31st.
The average temperature for the entire month was 32.2 – more than 3 degrees colder than the previous coldest October of 1988.
Afton temperatures October 2019
The chart below further illustrates this where it is noted that as of Mid-December temperatures had not dropped again to the record low levels of late October.
Afton temperatures Sept 1- Dec 14 2019
In contrast to the cold of October much of November was mild and dry, leading to a rather snowy first half of December.
Afton snowfall through December 14 2019