Northwest Montana

Issued: 10/29/2026 7:25 p.m. MDT

Tonight...Considerable clouds with areas of freezing fog and low clouds developing in the valleys overnight. Lows in the upper teens to upper 20s except mid 30s in breezy areas, near 30 in thermal belts on slopes, hillsides and around 5000 feet. Light wind except local east to northeast wind 10 to 20 mph through favored canyons and along portions of Lake Koocanusa. Ridge top winds east to northeast 15 to 25 mph with gusts to 30 mph.

Friday…Areas of freezing fog and low clouds in the valleys until early afternoon otherwise variable cloudiness and a little warmer. Highs in the lower 40s to lower 50s with upper 30s around 5000 feet. Light wind except local east to northeast wind 10 to 20 mph through favored canyons and along portions of Lake  Koocanusa in the morning becoming light by afternoon. Ridge top winds northeast 15 to 25 mph with gusts to 30 mph early then becoming light by afternoon.

Friday night…Increasing clouds with patchy valley freezing fog and low clouds developing. Lows in the 20s to near 30 except locally upper teens coldest valleys with upper 30s in thermal belts on slopes and hillsides with mid 30s around 5000 feet. Light wind.

Saturday...Patchy freezing fog and low clouds in the valleys through late morning otherwise considerable cloudiness and mild. Highs in the mid 40s to mid 50s with lower 40s around 5000 feet. Light wind.

Extended Outlook(Sunday through Thursday):

Sunday...Dry with areas of freezing fog and low clouds in the valleys across Lincoln County. A chance of valley rain and snow showers with a chance of snow showers in the morning across Sanders County then dry in the afternoon. Lows in the mid 20s to mid 30s with near 30 around 5000 feet. Highs in the 40s to near 50 with mid 30s around 5000 feet.

Monday through Thursday...No precipitation with areas of valley freezing fog and low clouds with partial late afternoon clearing. Lows in the 20s except upper 30s in thermal belts on slopes, hillsides and around 5000 feet. Highs in the lower 40s to lower 50s except locally mid 50s warmer valleys with sunshine and mid 40s around 5000 feet.

In-Depth Weather Discussion for Northwest Montana/North Idaho/Northern Rockies 

Issued 10/29/2026 7:25 p.m. MDT / 6:25 p.m. PDT

SHORT TERM (THURSDAY NIGHT THROUGH SATURDAY):       

     Well we finally have our first decent snowpack across the higher elevations across the region along with some decent rainfall that will slowly soak into the soils and finally putting an end to the fire season across North Idaho and Northwest Montana. Unfortunately the what seems like a never ending upper level ridge that has largely dominated the region since early May with just a few interruptions will reestablish itself across the region over the next week or so bringing a return to dry conditions and likely above average temperatures, at least in those areas that are either in the mountains or see sunshine in the valleys. It is late October and with the wet ground now valleys will see varying amounts of freezing fog and low clouds develop overnight and persist until early afternoon where they do develop and in some cases may not see any clearing at all especially as we head into next week. For the next 12 to 18 hours or so a surface high sliding down the east side of the Continental Divide along with a surface low off the Washington Coast will produce a weak northeasterly gradient and northeast winds across the typical areas of the Clark Fork River Valley and Lake Koocanusa as well as the Purcell Trench from Samuels to Athol so these areas will remain relatively mild overnight while calm valleys should drop down well below freezing which is expected in late October. Varying amounts of cloud cover can be expected as the upper level low spinning off the Washington Coastline will act with a weak jet stream to provide enough divergence aloft for a fair amount of mid and high cloudiness outside of the valleys that see stratus and fog. Clouds will tend to increase by Saturday night as a shortwave approaches from the south.                                           

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY): 

     Fairly uneventful period as our region will be largely dominated by upper level ridging across the Northwestern US and Northern Rockies. An upper level trough will pass by to the south of the region on Saturday night into Sunday and could bring just enough vertical motion and lift into mainly Sanders County in Northwest Montana for a few showers which could fall as rain or snow in the valleys and snow in the mountains but amounts will be light overall as the best dynamics and lift will remain well to the south of the area in California and Nevada. Unfortunately it looks like a pattern is shaping up across the North Pacific that we have seen many times in the past with a strong, consolidated jet racing across from Japan and making it about as far east as the Gulf of Alaska only to run into a strong upper level ridge positioned along or just off the British Columbia and Washington coastline forcing the jet to split as it approaches the coast with some energy heading north into northern BC and the stronger, southern branch heading into California leaving the Northern Rockies largely dry. This pattern looks to stay in place through much of next week with perhaps some signs of a breakdown in the ridge by next weekend but this is far from certain. Apart from a fair amount of mid and high cloudiness passing overhead valleys will be dealing with varying amounts of fog and low clouds that will likely fluctuate from day to day depending on the location of the surface high that will be residing over the region.