Good Morning! Today is Friday, September 18, 2026. Here is today’s forecast:
Another beautiful day ahead for north-central Montana. Skies will be partly to mostly sunny, with cloud cover increasing through the day. Most locations will stay dry, but a few isolated showers and thunderstorms are possible this afternoon and evening, mainly across the southern portions of north-central Montana. Around Helena, skies will be partly to mostly cloudy today, with scattered showers and thunderstorms developing during the late afternoon and evening. Highs today will be in the upper 60s and 70s.
A lot of north-central Montana will remain dry tonight and tomorrow, as the bulk of the rain is expected to stay south of a Great Falls-to-Winifred line. In Cascade, Judith Basin, and Fergus Counties, there are going to be scattered showers and a few thunderstorms around tonight and tomorrow. Around Helena, rain is likely tonight through tomorrow morning, with steadier rain transitioning to some scattered showers during the afternoon and evening. A few thunderstorms are also possible. Some of the rain may be heavy at times, especially in and around Helena.
Skies will be mostly cloudy to overcast for many areas tomorrow, but portions of the Golden Triangle and the Rocky Mountain Front will see some sunshine tomorrow.
Tomorrow night, showers and isolated thunderstorms are likely across eastern Montana, while there will be a few lingering showers around Helena and across north-central Montana. Showers will continue across the eastern half of the state on Sunday, but will gradually taper off as the day progresses. Across north-central Montana and around the Helena area, skies will be partly to mostly sunny Sunday, with increasing sunshine through the day. Some isolated showers and fog will be possible during the morning.
The highest rainfall amounts through Sunday evening are expected across southern Montana, where several areas will receive 1 to 2+ inches of rain. A FLOOD WATCH is in effect for most of south-central and southeastern Montana from 6pm Friday through 6pm Sunday. A FLASH FLOOD WATCH is also in effect for the mountains in central and southwestern Montana from Friday afternoon through Saturday evening/night due to the threat of flash flooding and debris flows on recent burn scars, including the Horse Gulch burn scar.
For the Helena area, including Helena and locations south and east of the city, 0.5" to 1.5" of rain is expected through the weekend. Lower rainfall amounts are expected north of Helena, with totals generally decreasing the farther north you go. A FLOOD WATCH is in effect for the Helena Valley, the Meagher County valleys, and the Canyon Ferry area from 6pm Friday through 6pm Saturday.
Across north-central Montana, a lot of locations will see little to no rainfall. However, up to one-third to one-half inch of rain is possible in southern Cascade, Judith Basin, and southern Fergus Counties. In northeastern Montana, up to .75 inches of rain is possible in Valley County, while up to .25 inches is possible in Phillips County.
Cooler temperatures are expected tomorrow around Helena and across Judith Basin and Fergus counties, where highs will be in the mid to upper 50s and low to mid 60s. Elsewhere, highs will be in the mid to upper 60s and low to mid 70s. On Sunday, highs are going to be in the 60s and low to mid 70s, with the coolest temperatures across northeastern Montana and across Judith Basin and Fergus Counties. There will be little to no wind around this weekend.
Beautiful early fall weather is expected next week as an upper-level ridge builds over the region. From Monday through Thursday, expect mostly sunny skies, mostly dry conditions, and above-average temperatures, with highs in the 70s and low to mid 80s.
Have a fantastic Friday and weekend!
Chief Meteorologist Ryan Dennis
