Sunday, February 2, 2025, was Groundhog’s Day. The real significance of this day is that it marks the halfway point of our astronomical winter season. It’s been six weeks since the Winter Solstice in December and there are still six more weeks until we reach the Spring Equinox in March.

This is also roughly the halfway point of our traditional ski season, between December 1st and April 1st. In this Post I will look back at the weather stats from December 2024 and January 2025 to see how this winter compares, so far, to the averages, and to the first half of last winter.

Town Snow

In December of 2024 the Jackson Climate Station recorded 28.8 inches of snowfall in town for the month.  That’s nearly a foot more snow than the long-term historic average for snowfall in December of 17 inches. The year before, December of 2023 only had 6 inches of snowfall for the month in town.

January 2025 wasn’t as bountiful, with only 10.2 inches of snowfall in town. That’s almost 9 inches shy of the average snowfall in town in January of 19 inches. The previous winter, in January of 2024, Jackson had 22 inches of snowfall, or 3 inches above the average for January.

Jackson’s total snowfall for December 2024 and January 2025 was 39 inches. The average total snowfall in town for these two months is 36 inches, so Jackson still ended up with above average snowfall for the first half of this winter.

This winter’s first half also beat the previous winter’s first half snowfall total by 11 inches. Total snowfall in town for December 2023 and January 2024 was 28 inches.

Town Temps

Temperatures in the Town of Jackson rode a thermal roller coaster in December and January. Historically, those two months have some of the biggest temperature swings of any months of the year in Jackson.

December of 2024 was relatively mild, with high temperatures running about 3 degrees above average and overnight low temperatures that were 7 degrees warmer than average. It would snow, then warm up, rain a little, then cool off. That process repeated itself a few times this past December.

Oddly, the warmest day this December came late in the month, on December 29th, 2024, the high was 43 degrees in town. The coldest temperature for the month was zero degrees, on three occasions, December 10th, 12th and 20th.

January 2025 was quite the opposite, with the average high temperature for the month more than 4 degrees colder than average and the average low temperature this January more than 6 degrees colder than the long-term monthly average.

The warmest day of the month was on January 3rd, 2025, which also had a high temperature of 43 degrees. The coldest day of the month was on January 20th, 2025, with a low of minus 26 degrees in Jackson. That came in the depths of an Arctic blast that we received from Canada, when it was also 20 below zero all the way up to the 10,000 foot elevation in the mountains.

The month of January 2025 racked up 20 days with morning lows that were zero degrees Fahrenheit or colder. For a total of 23 days in the two months of zero or colder.

A year ago, December of 2023 and January 2024 both had above normal temperatures in town, with a total of only 13 days with zero degrees Fahrenheit or colder.

The warmest temperature during the first half of winter last season was 49 degrees on December 5th, 2023. The coldest day was on January 16th, 2024, with a temperature of minus 28 degrees.

Mountain Snow

December of 2024 had 92 inches of snowfall recorded at the Rendezvous Bowl weather station around the 9,600-foot elevation at the Jackson Hole Mountain Resort. That’s above average and way better than December of 2023, which only had 55 inches. The long-term average snowfall at that site in December is 82 inches.

January 2025 also flip-flopped from the year before, with only 56 inches of snowfall at Rendezvous Bowl, which is well below January 2024’s total of 75 inches. Both of the last two January’s ended up short of the long-term average for snowfall in January at Rendezvous Bowl of 86 inches.

Total snowfall for the first half of this winter, 2024-25, at Rendezvous Bowl was 148 inches. That’s better than the previous December-January, 2023-24, which only had 130 inches of snowfall. Both however were still below the long-term average total snowfall for December and January combined of 168 inches.

You may recall what happened last year in the second half of winter, February and March were both way above average for snowfall, in town and in the mountains. Could we see a repeat performance this year?

Jim is the chief meteorologist at mountainweather.com and has forecast the weather in Jackson Hole for over 30 years

It’s Thanksgiving week and time to update the winter outlook for the coming months, as snow enthusiasts anticipate the powder yet to come. I’ll start with the latest outlook from NOAA for December through January, issued on November 21st, 2024.

NOAA’s Outlook

The long-range outlook from NOAA’s Climate Prediction Center for December 2024 through February 2025 shows that southern Idaho & most of Wyoming will have “Equal Chances” this winter for temperatures. The Equal Chances category means that the odds are the same for having above normal, below normal, or normal conditions. Below normal temperatures are expected for the northern tier of Wyoming & Idaho and for all of Montana.

Precipitation is expected to be in the above normal category for Northwestern Wyoming, as well as most of Idaho & Montana.

ENSO Forecast

El Nino is one phase of ENSO, the El Nino Southern Oscillation. An El Nino condition is when sea surface temperatures in the Equatorial Pacific are warmer than normal. A La Nina occurs when those temperatures are colder than normal. Both El Nino and La Nina have some effect on the weather patterns that develop across the Pacific Ocean, primarily during the Northern Hemisphere’s winter season.

Last winter (2023-24) was an El Nino winter. Usually, the odds are that El Nino winters won’t produce above average snowfall here in Jackson Hole. So, it depends on how you look at last winter, but it turned out OK in the end, with well above average snowfall in town (96 inches vs. 61 inches, for December through March) and just above average in the mountains (360 inches vs. 312 inches, for December through March).

Currently ENSO is in a neutral condition, a.k.a. “No Nino”. The ENSO forecast is for a weak La Nina to kick into gear anytime now….they give it a 57% chance now. But it was supposed to start sometime between September and November, and last through January-March of 2025.

Typically, a La Nina will favor more precipitation and more snow during the winter months over the northern tier of the United States, including Western Wyoming, while the Southwestern United States is generally drier during La Nina Winters.

Old Farmer’s Almanac

The Old Farmer’s Almanac prediction, which has been around since 1792. Their forecast for the Inter-mountain region – covering Utah, Idaho, Western Wyoming, and Western Colorado – claims that we will enjoy a snowy winter! Precipitation and snowfall will be average or above average region-wide, with the snowiest periods in mid-November, early and late January, and mid-March. Although, the map below shows “Mild & Dry”  over Idaho & Western Wyoming…hmmm?

The Almanac goes on to reveal that temperatures won’t be especially frigid, staying above normal this winter. In other words, mild. The coldest temperatures will come in late November and late January.

Coin Flip

Long-range outlooks are always a crapshoot, sometimes even short-range forecasts are known to bust. I like the odds with a La Nina of seeing at least a normal winter’s snowfall around here, or better. Recent winters here in Jackson Hole have produced way more snow than I wanted to shovel, along with plenty of powder to ski, during El Nino and La Nina years.

One last bit of snowfall trivia: 8 out of the top-ten snowiest winters at the Jackson Hole Mountain Resort occurred within the last 15 years. Five of those top-ten winters happened within the last six years. Two winters ago, 2022-23 ranked as the second snowiest on record. The winter of 2021-22 was the only year in the last six that had below average snowfall on the mountain. Question is, does the snowy trend keep rolling, or are we due for a bust?

Post by meteorologist Jim Woodmencey
Nov. 24, 2024