Temperature inversions are observed when the air temperature increases with height. Under normal weather conditions, the air temperature typically decreases with height. 

A classic example is when colder air settles into mountain valleys during times of stable, high-pressure weather conditions. Colder, denser air pushes under the warmer, less dense air in the valley, which creates the inversion.

For places like Jackson Hole, inversions can lead to very cold temperatures and valley fog near the bottom half of the mountain, followed by much warmer temperatures (30+°F) and abundant sunshine as you climb to the upper half of the mountain. 

Temperature inversions can also trap polluted air in urban environments that have specific topographic features. Salt Lake City is one location that is known for bad air quality due to inversions during prolonged periods of stable, high-pressure weather conditions in the winter months. The inversion traps the polluted air, which is caused by emissions due to the burning of fossil fuels.

Weather Patterns that Cause Temperature Inversions

Upper-level ridges with associated high-pressure systems are one type of weather pattern that causes temperature inversions. This type of weather pattern causes colder, denser air to sink into the valleys while the warmer air stays in the higher elevations.

• Temperature inversions with high pressure can happen across North America, but are most common in mountainous areas.

This ridge of high pressure has brought dry and clear weather throughout the Western US during mid January of 2026. A closer look at surface temperatures in this ridge over the Pacific Northwest shows the temperature inversions across the mountainous area.

The areas that are cooler in the valleys are often associated with low clouds, fog, and trapped pollutants. High-pressure systems are like a weighted blanket and push cold air and moisture to the surface. High-pressure also does not let the air rise, therefore keeping pollutants at the surface.

Another type of weather pattern that leads to temperature inversions is called cold air damming. This primarily occurs in storm systems in mountainous areas, especially over the Appalachian Mountains, and can lead to mixed precipitation events. In these types of weather systems, cold air will stay at the surface while warmer air moves above it.

When precipitation moves into this temperature inversion, it can melt and then refreeze, producing freezing rain or sleet. Below is an example of temperature inversions from the National Weather Service that cause snow, sleet, or freezing rain.

Weather Associated with Temperature Inversions

The weather with a temperature inversion can be vastly different depending on whether it is a ridge of high pressure or a storm system moving warm air over cold air.

• A ridge of high pressure will bring cold temperatures to the valley, which is often associated with low clouds, fog, and poor air quality. Ridges can also bring clear skies with poor air quality to the valleys, if there are dry enough conditions to prevent low clouds and fog.
• Mixed precipitation events will bring icy conditions and several different types of precipitation.

Skiing and Temperature Inversions

Based on the weather conditions above, skiing and riding will be affected by temperature inversions. Ridges of high pressure usually bring beautiful conditions due to warmer and clearer conditions in the mountains above the valleys. This type of weather is not for powder chasers, but it is still spectacular to have clear skies, warm temperatures, good air quality, and often low clouds below.

• It can be cloudy and cold in town or at the base, but sunny and warm at mid-mountain to the summit.

Check out Bogus Basin on January 14, 2026 with sunny skies and warm temperatures above the inversion layer in Boise, ID.

Mixed precipitation events are not good for skiing due to ice accumulations from sleet or freezing rain. Freezing rain is worse than sleet and can be severe at times. Freezing rain accumulations over 0.25 inches can bring severe impacts, like downed trees and power outages.

Common Questions

• Where do temperature inversions occur?
  • Anywhere! Temperature inversions can occur anywhere, but are most likely to occur in mountain valleys.

• How long do temperature inversions last?
  • They can last from a few hours to several days and even weeks! It all relates to the weather pattern and whether it moves through quickly or remains stationary.

• In what season do temperature inversions occur?
  • Any season! Temperature inversions occur year-round, but are most common during the fall to winter, due to colder air that is more likely to sink in mountain valleys.

Fun Fact

One of the regularly coldest areas in the US, which has one of the most severe temperature inversions, is in northern Utah. It is called Peters Sink and is a small basin that experiences severe temperature inversions. It does so because it essentially is a valley within a mountain. This causes cold air at the relatively high elevation of 8,173 feet to be magnified within this small depression in the mountainous area.

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Zach Butler