The Treasure Valley and central Idaho are settling into a stretch of beautiful fall weather into the weekend, but residents should prepare for frosty conditions tonight and choose Saturday over Sunday for outdoor plans.
Frost Advisory in Effect Tonight
Tonight brings the season's most significant frost threat so far. A Frost Advisory has been issued for the Upper Treasure Valley east of Boise and the Western Magic Valley, where a cool air mass and lighter winds will allow pockets of frost to develop.
High clouds moving overhead will help prevent even colder temperatures from developing. This means the Boise metro area and Lower Treasure Valley should see lows stay in the upper 30s to around 40 degrees, while more rural and elevated areas could see frost formation.
Gardeners and those with sensitive plants should take precautions, as this marks a significant shift toward more typical late October conditions.
Saturday: The Weekend Winner
If you're planning outdoor activities this weekend, Saturday is clearly the better choice. An upper-level ridge will briefly move overhead, bringing lighter winds and mostly sunny skies with high temperatures reaching a comfortable 65 degrees.
Saturday offers ideal conditions with calm winds - perfect for hiking, outdoor sports, or any fall activities you've been planning. The combination of sunshine, mild temperatures, and light winds makes it a standout day for the season.
Friday Sets Up the Weekend
Friday will be mostly sunny with highs near 65 degrees - a few degrees warmer than recent days and right around normal for mid-October. A trough moving by to the north will bring another day of breezy winds, but conditions will remain dry across the Treasure Valley.
Friday night brings another frost concern, with pockets of frost again expected in lower valleys as temperatures drop to around 40 degrees.
Sunday's Less Ideal Conditions
While Sunday won't be a washout, it's definitely the lesser of the two weekend days. Sunday will start with increasing clouds and a 40% chance of showers developing later in the day as a weather system moves into the region.
The system will bring breezy conditions with wind gusts up to 30 mph, making it less comfortable for outdoor activities. High temperatures will also be slightly cooler at 62 degrees compared to Saturday's 65 degrees.
For most Treasure Valley locations, any rainfall will be light - typically just 0 to 0.1 inches. Many areas may experience only brief light rain or drizzle rather than steady precipitation, but the combination of clouds, occasional showers, and gusty winds makes Saturday the clear winner for weekend plans.
Brief Mountain Impact
The higher elevations may see some light snow accumulation on Sunday, but this will be limited to the highest ridges and won't significantly impact most recreational activities or travel routes.
Cooler Start to Next Week
Monday will feel noticeably different as temperatures drop to around 56 degrees - about 10 degrees below normal for the date. However, this cooler pattern won't last long.
Tuesday and Wednesday will see temperatures slowly rise back to normal levels, with sunny skies returning and highs climbing back into the 60s by midweek.
Looking Ahead
The weather pattern through next week will be mostly stable, with sunny conditions dominating and temperatures gradually warming back to seasonal norms. Thursday looks particularly nice again with mostly sunny skies and highs near 65 degrees.
Daily Forecast
Tonight: Increasing high clouds, with a low around 42 degrees. NW winds becoming calm in the evening.
Friday: Mostly sunny with some high clouds at times and a high near 65 degrees.Wind NW 5-12 mph.
Friday Night: Mostly clear, with a low around 40 degrees. Wind becoming light.
Saturday: Sunny, with a high near 65 degrees. Calm wind.
Saturday Night: Mostly clear, with a low around 46 degrees. East southeast wind 3 to 7 mph.
Sunday: Increasing clouds with a 40% chance of showers later in the day. and a high near 62 degrees. Expect the breeze to increase later in the day.
Sunday Night: Partly cloudy, with a low around 37 degrees.
Monday: Sunny, with a high near 56 degrees.
Monday Night: Mostly clear, with a low around 36 degrees.
Tuesday: Sunny, with a high near 60 degrees.
Tuesday Night: Partly cloudy, with a low around 37 degrees.
Wednesday: Sunny, with a high near 61 degrees.
Thursday: Mostly sunny & milder, with a high near 65 degrees.
Stay connected right here for updates to my weekend forecast!
