Westby, Montana Weather
Pikas hayfeeding in granite peaks. Day 78 of spring. Read this microseason across nine climate regions →
Westby weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 5Foggy17%—82°51°—
- SaturdayJun 6Light Showers68%—94°58°+12°
- SundayJun 7Light Showers68%0.03″79°54°-15°
- MondayJun 8Overcast33%—77°48°-2°
- TuesdayJun 9Overcast41%—81°61°+4°
- WednesdayJun 10Overcast41%—72°53°-9°
- ThursdayJun 11Light Drizzle44%—60°52°-12°
AQI 31 (Good), driven by PM2.5. AQI down 6 over the last 6 hours (steady decline since this morning). PM2.5 at 4.5 µg/m³ (AQI 25) with a 0.82 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 4.5 µg/m³ (AQI 25) with a 0.82 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.82
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 6:25 AM
- Moonset
- 3:41 PM
- In sign
- ♒︎ Aquarius
Pikas hayfeeding in granite peaks
Westby at a glance
- Today vs. normal: 12°F below the seasonal normal for this latitude
- Last frost: June 8 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Warm-season window is open
As of June 5, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
SPC Convective Outlook
Storm Prediction Center — Westby
SPC has placed Westby in the Slight Risk category for severe thunderstorms tomorrow.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWSLGTSlight Risk
- DAY 3SLGTSlight Risk
Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.