JACKSON, Wyo. – May was warmer and drier than average in Teton County, though beneficial rain arrived toward the end of the month. Confidence is lower than usual for the month of June this year in terms of temperature and precipitation, with more recent model trends suggesting near-average conditions.
Recent Weather Pattern
The weather pattern from Wednesday to Friday of last week featured warm and dry conditions, with a high of 83ºF recorded in the town of Jackson (JKNW4 weather station) last Wednesday.
However, a low pressure system moved into the area over the weekend, bringing cooler temperatures and some much-needed rainfall.
The initial burst of rain early on Saturday morning proved to be the heaviest, with the town of Jackson picking up an inch of rain in less than 6 hours early in the morning. Over the rest of the weekend, showers were lighter and more intermittent, but chilly temperatures also prevailed.
Areas above 9,000 feet in the Tetons also picked up a few inches of snow over the weekend.
Dry and sunny weather has returned to the area early this week, though the warm-up has been very gradual.
Temperatures have dipped to near freezing in the valley on each of the past 3 mornings, while afternoon highs have been a little bit warmer each day.
Here is the 7-day weather summary for the town of Jackson:
For perspective, the average high and low temperatures in Jackson on June 3 are 67º and 37º.
May 2026 Review
May was warmer and drier than average overall, but the final third of the month was much more active compared to the first two-thirds of the month.
From May 1-20, the town of Jackson received a paltry 0.03 inches of precipitation. However, from May 21-31, the town of Jackson received a healthy 1.91 inches of precipitation.
For the month as a whole, Jackson received 1.94 inches of precipitation which is slightly below its long-term average of 2.16 inches. But the final stretch of May saved it from being a “well below average” month for precipitation.
Zooming out, precipitation was still below average across Western Wyoming and Eastern Idaho for the month as a whole.
Jackson did see a trace of snowfall for the month of May, while the Rendezvous Bowl Plot at Jackson Hole’s upper mountain received 10 inches of snowfall for the month. The long-term May snowfall average (2007-2025) at the Rendezvous Bowl Plot is 31 inches, so this year was a bit below average.
In terms of temperature, the month of May was slightly warmer than average, but we saw more high and low temperature extremes than we usually do at this time of year. The dry pattern during the first three weeks of the month played a role in this, with larger diurnal swings than normal.
When factoring in both high and low temperatures, May 2026 ended up 1.2 degrees warmer than normal in the town of Jackson, based on data from the JKNW4 weather station compared to the 2010-2025 average.
Zooming out, temperatures in May were slightly above normal across Eastern Idaho and the northern two-thirds of Wyoming, and slightly below normal across the southern third of Wyoming.
The average high temperature in Jackson of 65.8ºF in May 2026 was well above the 2010-2025 average of 61.1ºF. However, the average low temperature of 31.3ºF was below the 2010-2025 average of 33.5ºF.
In terms of warmth, we had three days of 80+ degree high temperatures in Jackson, which is atypical for May. From 2010 to 2025, we only hit 80ºF in May in 5 of these 16 years at the JKNW4 station in Jackson. The average first 80ºF day in Jackson is June 6.
An 80ºF day was also recorded in Jackson as early as May 13. When examining data from the COOP weather station in Jackson, this was the earliest in the year that Jackson hit 80ºF since 2001.
On the other hand, chilly mornings were common throughout May, and a low of 17ºF was recorded on May 19, which is a bit later than usual for our last sub-20 degree temperature of the season. This was also just two degrees shy of a record low for the date.
May continued a trend of alternating wet and dry months since October. Precipitation in Teton County was above average in October, December, February, and April, and below average in November, January, March, and May.
For the water year as a whole (since October 1st), precipitation is currently above average in Jackson and near average for the Greater Teton Area as a whole, despite the lackluster snow season.
Upcoming Weather Pattern
Warm, dry, and breezy conditions will prevail from Wednesday to Friday. Highs will reach the mid to upper 70s most days, but could potentially crack 80ºF on Friday.
Starting this weekend and heading into next week, a transition to a more unsettled weather pattern is expected.
Over the weekend, the first low pressure trough will approach from the west. Ahead of the trough, a warm and breezy day is expected on Saturday with highs in the 80s, but a chance of thunderstorms is also expected in the afternoon.
On Saturday night and Sunday, a cold front will move through with scattered showers possible during both the morning and afternoon hours (exact timing and coverage TBD), while temperatures will also be a bit cooler.
A slow-moving trough of low pressure is then expected to push into the Western U.S. next week, resulting in near-daily chances for showers and thunderstorms. Temperatures may start out warm initially on Monday, but are then projected to dip below average mid to late next week.
The 7-day precipitation projection below represents the average of 50 simulations of the European AIFS Model. While confidence is low in the details for early next week, overall it’s a decent moisture signal for this time of year, and the forecast has been trending wetter for this period over the past couple of days.
June 2026 Outlook
June is a month in which we transition from spring to summer conditions in Jackson, and we can see elements of both with stretches of warm and dry conditions occasionally interspersed with stretches of cool and wetter conditions. Thunderstorms are also common in June.
Historically, June is the third warmest month of the year in Jackson, but average temperatures are still well below what we typically see in July and August.
The average high temperature in Jackson in June is 73.1ºF, and the average low temperature is 40.3ºF. Early in the month, average highs are in the upper 60s, while late in the month, average highs are in the upper 70s.
In the past 16 years, we have seen temperatures as high as 93ºF (in 2015) to as low as 24ºF (in 2024) in the month of June.
Average rainfall in June in Jackson is 1.32 inches, making it the second driest month of the year behind July. However, June rainfall can fluctuate significantly from year to year. Last year, Jackson only received 0.37 inches of rain in June, but in 2023, Jackson received 2.64 inches of rain in June.
Snow can occasionally fall across the higher elevations of the Tetons in June, and there have been years in which significant snow fell at 9,000-10,000 feet in June, though it hasn’t happened in a while.
In the valley, snow is rare but not unheard of in June. However, when it does occur, it typically does not accumulate, at least in town and in the lower valley. The most recent instances of a “trace” of snowfall in the town of Jackson in June were in 2024 and 2014.
Severe thunderstorms are less common in Teton County compared to most of the country, but they can occasionally happen, and historically, June is the month in which they are most likely to occur.
To be classified as “severe”, a thunderstorm must produce one of the following: 58 mph wind gusts, 1? diameter hail, or a tornado.
In June of 2022, an EF-2 tornado hit the Gros Ventre Wilderness just north of Sheep Mountain, producing a 2-mile damage path through a heavily forested area. The same weather system also produced devastating flooding in Yellowstone.
For June of 2026, confidence in the monthly outlook is lower than usual as weather models more than 7-10 days out have been struggling to get a handle on the weather pattern lately.
NOAA’s monthly outlook, which was published at the end of May, projected warmer and drier-than-normal conditions for the Jackson Hole area in June.
However, since that outlook was published, recent model trends (notably from the highly-regarded European Model) are beginning to back away from this projection and are hinting at more frequent troughs moving into the Western U.S., which could bring periods of cooler and wetter conditions.
A strong El Niño (well above-average sea surface temperatures) is also emerging in the Tropical Pacific, and this should start to have an atmospheric response sooner rather than later – and this response is typically more frequent summer troughs than usual in the Western U.S. that historically have correlated to above-average summer rainfall in our region.
As a result of the recent model trends and the historical El Niño correlations, I am leaning more toward near-average temperatures and precipitation for our area in June, though we will likely see some alternating periods of warm and dry weather with cooler and wetter stretches.
Alan Smith, Meteorologist
