JACKSON, Wyo. – Jackson is forecast to experience its hottest temperatures in years this weekend, with highs in the mid 90s on Saturday and upper 90s on Sunday. Some locations across Western Wyoming will challenge all-time high temperature records.
Recent Weather
The first week of July featured below-average temperatures before the Fourth and a transition to above-average temperatures after the Fourth, but no extremes in either direction.
Overall, it’s been a nice stretch of weather, although afternoon thunderstorms have also been common thanks to frequent Pacific disturbances tracking across the Northern Rockies.
Jackson received measurable rainfall on five of the past seven days. In most instances, rain was brief and light, but a heavier downpour on Friday produced 0.19 inches of rain.
During the first week of July, Jackson received a total of 0.31 inches of rain, while a limited number of rain gauges in the Tetons recorded anywhere from 0.4 to 0.9 inches of rain.
Here is the 7-day weather summary for the town of Jackson:
For perspective, the average high and low temperatures in Jackson on June 24 are 81º and 43º.
Upcoming Weather Pattern
We are transitioning into a drier weather pattern this week. Minor disturbances are tracking across the Northern Rockies, but only a slight chance of afternoon thunderstorms is expected on Wednesday and Thursday across the Tetons, with higher chances further east.
Temperatures will be quite warm on Wednesday and Thursday again, with highs in the mid 80s, but it will be more tolerable compared to what’s ahead.
Over the weekend, a strong ridge of high pressure will set up over the Central and Northern Rockies, and confidence is growing that a substantial heat wave will take hold across Wyoming and Eastern Idaho.
Highs will reach the upper 80s to near 90 in Jackson on Friday, before soaring into the mid 90s on Saturday and upper 90s on Sunday, both of which will challenge daily record highs.
Based on the current forecast, Sunday could very well end up in the top 10 for the hottest days on record in Jackson, and possibly even the top 5. Using a blend of weather models, the high is currently projected to reach a scorching 98ºF in Jackson on Sunday afternoon, and models have been consistent on this projection for several days now.
How would this stack up historically if this forecast were to verify?
The hottest temperature on record in the town of Jackson is 101ºF, which occurred on two different days in July of 1934. The next highest temperature after that is 98ºF, which occurred in 1934 and more recently in 1981.
The most recent “extreme” high temperature in Jackson occurred in July 2003 when we hit 97ºF.
Here is a list of the top 10 hottest temperatures ever recorded in Jackson, with data going back to the early 1900s (note: there are some missing data in Jackson’s historical records).
It’s interesting to note that 9 of these top 10 readings occurred in just two years, in 1934 and in 2003, with the other one occurring in 1981.
On average, Jackson hits 90ºF or higher four to five times per year, while 95ºF or higher temperatures are very rare.
At the JKNW4 weather station in Jackson (data going back to 2010), a high of 95ºF was recorded most recently in August of 2024, but the long-term climate station in Jackson reported a lower reading than this. Before that, the most recent 95+ reading occurred during the July 2003 heat wave referenced above.
Across Western Wyoming as a whole, some locations are expected to challenge all-time temperature records, and most areas below 6,000 feet east of the Divide are looking at triple-digit heat on Sunday.
While the peak of the heat wave is expected on Sunday, it looks like Monday will be another hot day with highs forecast to reach the mid 90s.
While we (thankfully) have much cooler nights and lower humidity compared to most of the United States, this kind of heat is still intense for our area, especially in the direct sun, and should be taken into consideration when planning outdoor adventures this weekend.
Temperatures should start to moderate by the middle of next week and even more so toward the end of next week as monsoon moisture begins to push into our area from the south.
Initially, this will result in increased cloud cover and at least some thunderstorm potential by as early as Tuesday. Overall, the 7-day rainfall projection map looks unimpressive for our area, since the monsoon will just be getting started around this time next week.
However, medium to longer range models have consistently been on board with a strong monsoonal flow pattern setting up during the second half of next week, with abundant subtropical moisture reaching our area.
It looks like this monsoon pattern could have some staying power as well, which would result in an increase in thunderstorm activity and a growing likelihood of “wet” thunderstorms that would hopefully bring us some welcome mid-summer moisture.
Keep in mind, we are still about a week away from this possible pattern change, so nothing is guaranteed. But the longer-range signals for a wetter and stormier second half of July have been consistent for a while now.
Alan Smith, Meteorologist
