Boise, ID – Idaho faces a winter-weather mix from December 18–24, with NOAA’s long-range outlook indicating above-normal precipitation statewide and temperatures ranging from below-normal in northern Idaho to near-normal and slightly above-normal farther south. This highly variable setup increases the potential for snow, freezing rain, sleet, fog, and difficult Christmas travel across broad sections of the state.
According to NOAA, northern Idaho—including Coeur d’Alene, Sandpoint, Lewiston, and the Panhandle—sits under the strongest signal for accumulating snow. With temperatures trending colder than normal, multiple disturbances may bring steady snow from December 19–23, including areas of heavier banding along U.S. 95 and the Bitterroot foothills.
In central Idaho, including McCall, Cascade, Salmon, Ketchum, and Sun Valley, moisture arriving during marginal-temperature windows may introduce periods of freezing drizzle or light icing, especially between December 19–21. Valley locations may experience slick conditions while higher elevations receive moderate to heavy snow.
Across southern Idaho—including Boise, Nampa, Mountain Home, Twin Falls, and Pocatello—precipitation may begin as rain or a rain–snow mix, depending on elevation and time of day. However, colder air approaching from the north between December 22–24 may transition much of the region to wet snow as Christmas Eve approaches.
Mountain passes—including Lolo Pass, White Bird Grade, Galena Summit, Banner Summit, and Lookout Pass—are likely to experience heavy snowfall, blowing snow, and treacherous conditions.
Major highways—including I-84, I-90, U.S. 20, U.S. 93, and U.S. 95—may see slick roads, low visibility, freezing fog, and delays, especially from December 21 through Christmas Eve.
