Cold front makes for cool and windy Monday

Frost Advisory in effect through 9am for the Valley and rural communities.

A cold front moving into Eastern Idaho and western Wyoming today is bringing cooler temperatures in the mid-60s across lower elevations. Winds are expected to be between 15 and 20 mph, creating breezy, fall-like conditions across the region.

The shift in weather provides a temporary drop in temperatures following recent warmth, accompanied by morning lows dipping into the 40s and 50s. Clear skies and a westerly flow will allow conditions to warm back up gradually through midweek.

6–8 AM

40s–50s

Cool start with a noticeable breeze. This is the morning for the light jacket, coffee, and maybe an extra layer if you’re heading out early.

9–11 AM

50s–60s

Sunshine begins doing its work, but the air still has that crisp, fall-like feel. Great for the school drop-off, a walk, or getting outside before the afternoon breeze picks up.

Noon–2 PM

Low–mid 60s

Bright skies and temperatures settling into the 60s. The breeze remains part of the story, so it may feel cooler than the thermometer suggests.

3–6 PM

Mid-60s

Our warmest stretch, but still a genuine taste of fall. Winds around 15–20 mph keep the afternoon feeling active, especially in open areas and along the Snake River Plain.

7–10 PM

Cooling through 50s

Clear skies and a quick evening cool-down. A good night for a sweatshirt, an outdoor fire, or wrapping up those evening chores before temperatures dip.

Tonight: Mostly clear with lows in the 40s. The cooler air will be especially noticeable in the mountain valleys and across western Wyoming.

Tuesday — Sunshine, Still a Little Fall in the Air

Tuesday keeps the bright, dry pattern going. We’ll start in the 40s, warm through the 50s during the morning, and reach the upper 60s to low 70s for many spots by afternoon. Breezes continue, generally 15–20 mph, so it’s a pleasant day for outdoor plans, but not necessarily a still-air day.

• Morning: Light jacket weather, cool enough for a hoodie.
• Afternoon: Sunshine, low 70s, and a breeze that keeps things comfortable rather than hot.
• Evening: Clear skies and temperatures sliding back through the 50s.
• Overnight low: 40s.

Wednesday — Back Toward 80

The warm-up becomes more noticeable Wednesday as westerly flow helps bring temperatures back up.

Hour-by-hour feel:

• 6–8 AM: Cool start in the 40s.
• 9–11 AM: Sunshine and temperatures climbing through the 50s and 60s.
• Noon–2 PM: Low to mid-70s, comfortable for lunch outside or getting things done.
• 3–6 PM: Upper 70s, with some spots near 80. Warmest day of the stretch.
• Evening: Mild at first, then cooling through the 60s.
• Overnight: Lows in the 40s.

This is the day to enjoy the warmer weather before the next weather-maker begins to show up.

Thursday — Warmer First, Then a Little More Unsettled

Thursday starts mild, with highs making it back into the 70s and some lower elevations possibly getting close to 80. But we’ll be watching a little more moisture and instability moving in.

The slight chance of showers and thunderstorms is mainly into the afternoon and evening. Most locations stay dry, and if we do see a shower or storm, it should be more of a brief interruption than a soaking rain event. No significant accumulation is expected.

• Morning: Mild, with temperatures rising quickly.
• Afternoon: 70s, breezier, and a little more cloud cover.
• Late afternoon–evening: Slight chance of showers or a thunderstorm.
• Overnight: Cooling into the 40s.

Friday — Seasonal and Comfortable

Behind the Thursday system, temperatures reset to the low 70s. We’ll keep a seasonal feel with a mix of sunshine and some passing clouds. Any lingering shower chances should be limited, and most of the region looks dry.

Morning lows: 40s Afternoon highs: Low 70s Evening: Comfortable, with temperatures cooling through the 60s.

Saturday — A Good Weekend Setup

Saturday continues the seasonal trend with highs mainly in the 70s. That’s a comfortable range for outdoor plans, travel, yard work, golf, or getting out to enjoy the early fall scenery. We’ll watch for any passing clouds or isolated shower chances, especially near the mountains, but the overall setup looks fairly manageable.

Morning: Cool and crisp, 40s. Afternoon: Mostly sunny to partly cloudy, 70s. Evening: Comfortable, then cooling back into the 50s.

On Tuesday, temperatures will start in the 40s before rising into the upper 60s to low 70s by the afternoon. Winds between 15 and 20 mph will persist throughout the day under sunny skies.

A westerly wind flow will warm the region further on Wednesday. High temperatures are expected to reach near 80 degrees under sunny skies, marking the warmest point of the week.

Mild weather will continue into Thursday, with highs reaching the 70s and some lower elevations approaching 80 degrees. An influx of atmospheric moisture and instability will bring a slight chance of showers and thunderstorms during the afternoon and evening, though no significant rain accumulation is expected.

Following Thursday's system, temperatures will reset to the low 70s on Friday. Weekend temperatures are expected to remain in the 70s under mostly sunny to partly cloudy skies.

Jeff Roper, First Alert Weather