La Niña is expected to bring colder temperatures and more snow to Idaho this winter

With the first frost of the season expected in Boise this week, the Gem State can expect winter temperatures to shift through the end of the year.

The National Oceanic and Atmospheric Administration released its winter outlook on Thursday, October 17th. This indicates that Idaho can expect slight changes to normal winter temperatures as La Niña is expected to influence winter conditions across most of the country.

Here's what to expect.

How does La work? Niña affect the weather?

A La Niña occurs when ocean temperatures in the eastern Pacific are cooler, leading to less evaporation, weaker storms and less moisture in the atmosphere, according to NOAA. The colder waters of the Pacific Ocean rise to the surface, pushing the jet stream further north toward Alaska before descending south into the northern United States.

“La Nina conditions are expected to develop later in the fall and typically result in a more northerly storm track during the winter months,” NOAA’s 2024-2025 Winter Outlook says.

While the southern United States can expect a drier and warmer winter, northern states like Idaho can expect slightly below normal temperatures and slightly more precipitation.

What is the impact on Boise?

Northern and central areas of Idaho can expect slightly colder weather and more precipitation between November and January, according to Les Colin, a senior meteorologist with the National Weather Service in Boise.

However, Boise and the rest of southern Idaho are expected to experience normal rainfall for this time of year, and residents can look forward to slightly warmer temperatures.

“This suggests that we would have more snow than normal as normal temperatures would certainly bring a lot of snow to the mountains and the additional precipitation would produce more than normal amounts of snow,” Colin said in a telephone interview with the Statesman. “So what's shown here is normal or slightly above normal temperatures in southern Idaho, but more than normal precipitation would mean more than normal snowfall, particularly in the mountains.”

Colin said he also expects excessive snowfall in the mountains and northern Idaho as temperatures will be colder and below freezing. There's also the possibility, he said, that this weather pattern could continue into March next year.