Climate and Precipitation
From Sustaining Jackson Hole Wiki
An an alpine environment like Jackson Hole’s, weather can vary tremendously. For instance, some of the strangest weather events during the 1990s included snow on the Fourth of July and rain at Christmas. Winter temperatures several times a year usually plummet to 20 below zero, and the record low is 63 below Fahrenheit. In the summer, July and August can bring temperatures in the 90s, and the record high is 98 Fahrenheit.
While the weather always brings unexpected surprises, averages offer an idea what it feels like in Jackson Hole from season to season.
During the summer, Jackson Hole is often sunny and arid, though thunderstorms will frequently build over the valley during the day and bring precipitation in the afternoon. On average, July is the warmest month of the year. Using 50 years of data collected in the Town of Jackson, the average high temperature is 81 degrees Fahrenheit and the average low is 40. At Summer Solstice in late June, there is a little more than 15 hours of daylight.
At Winter Solstice in late December, there is roughly 9 hours of daylight. The coldest month of the year is January, with an average high of 27 and an average low of 5 degrees. January is also typically the snowiest month of the year, with an average of 20 inches in town and 86 inches in the mountains at 9,000 feet. In the winter, the weather can vary from cloudy and gray during a snowstorm to completely sunny skies. When skies are clear, temperature inversions often trap cold air in the valley, bringing temperatures well below zero, while temperatures in the mountains can reach the 20s or 30s.
May is typically the wettest month, with an average of 1.9 inches of precipitation. The next in order are June with 1.68 inches, December with 1.65 inches, and January with 1.51 inches. (When precipitation falls as snow or in other frozen forms, meteorologists track its water content.) Over the year, the Town of Jackson receives an average of 16.23 inches of moisture and 75 inches of snow. The snowiest winter on record was 1996-97, which saw about 500 inches of snow in the mountains between December 1 and April 1, roughly the dates the ski areas are open.
In the spring and fall, the weather can be quite variable. Spring often brings cloudy skies and rain or snow. In fact, the rainiest day on record – 1.8 inches in one day – was March 3, 1995. Fall often brings both extended warm periods and significant snow.
Source: Meteorologist Jim Woodmencey and mountainweather.com
