In my Dec. 30 column I covered most of the significant weather events that occurred around Jackson Hole during 2020, including the individual records that were broken.
For this week’s column I have compiled all the weather stats for the town of Jackson from the year 2020, the stats that become part of the story of our local climate.
All data presented comes from the Jackson Climate Station, located on the north end of town.
The average high temperature for the entire year in 2020 was just under 52 degrees. That is 2 degrees colder than the long-term historic average annual high temperature of 54 degrees.
In 2019 the average high temperature was only 49 degrees. That was the coldest average annual high temperature ever.
January, March and August of 2020 were the only months of the year that saw average high temperatures above normal. Every other month checked in with below-normal high temperatures.
The hottest temperature recorded at the Jackson Climate Station in 2020 was 88 degrees on Aug. 17. There were no days that officially reached 90 degrees in town.
The average low temperature for the entire year in 2020 was 23 degrees. That is precisely what the long-term average annual low temperature is for Jackson. In that respect, 2020 was totally normal.
January, March, May, June and August 2020 were all just above the average for monthly low temperatures. February 2020 was almost 7 degrees colder than average, November was 3 degrees colder than average and December was around 5 degrees colder than average. The other months of 2020 were close to the average monthly low temperatures.
The coldest day of the year back in 2019 was 25 degrees below zero on Jan. 1. In 2020 the coldest day of the year was also 25 degrees below zero, but it took until Feb. 20 to match that temperature.
Also of note was the coldest temperature ever recorded in the month of October, which occurred in 2020 when it dropped to 9 below zero on Oct. 26. That beat the old October low temperature record, set the previous year, when it dropped to 6 degrees below zero on Oct. 30.
If you take the average of all the monthly high temperatures and all the monthly low temperatures for the year, you generate what is known as the annual mean temperature. This is the best gauge of the overall temperature for the entire year.
The annual mean temperature for Jackson in 2020 was 37.5 degrees. That tied for the eighth coldest year on record.
In 2019 the annual mean temperature was 35.4 degrees — cold enough to qualify as the coldest annual mean temperature on record in Jackson.
The coldest year on record before 2019 was 1944, which had a mean temperature of 35.5 degrees.
Keep in mind: To be in the competition for the coldest or warmest year ever, you need 12 months of complete weather data. Of the last 97 years, dating back to 1923, 36 years had too many missing days or months of data to be able to calculate accurate annual mean temperatures. So the year 2019 was the coldest out of the 61 years with complete data.
For trivia’s sake, the hottest annual mean temperature in Jackson’s climate record was 47.5 degrees, way back in 1933.
Precipitation and snow
After a recent run of four years in a row with above-normal annual precipitation, from 2016 to 2019, the town of Jackson experienced a drier-than-normal year in 2020, though not by much. Total precipitation in Jackson in 2020 was 15.22 inches compared, with a long-term average of 15.83 inches.
Total snowfall in 2020 was a different story. We are presently on a five-year run with above-average annual snowfall, and 2020 was the biggest of them all.
For the calendar year 2020, which actually includes parts of two winter seasons, Jackson received 121 inches of snowfall. In 2019 we had over 111 inches. The average annual snowfall in the town of Jackson is 77 inches.
I could find only three other years in which the annual snowfall was greater than 121 inches in Jackson. The biggest of those years was in 1967, with 155 inches. The other two were in 1971 (130 inches) and 1973 (123 inches). Again, these are among years that have complete records.
Our weather in Jackson for 2020 could be summed up simply as this: It was colder and much snowier than normal, along with close to normal precipitation.