Boulder, Montana Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Boulder weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast27%—70°52°—
- FridayJun 5Overcast——81°48°+11°
- SaturdayJun 6Overcast38%—82°47°+1°
- SundayJun 7Heavy Snow Shwrs42%0.82″49°40°-33°
- MondayJun 8Light Drizzle28%—66°40°+17°
- TuesdayJun 9Overcast51%—67°51°+1°
- WednesdayJun 10Light Drizzle59%0.01″67°49°0°
Ozone at AQI 35 now. AQI down 6 over the last 6 hours (steady decline since this morning). With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 16 by mid-afternoon.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 35 now. With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 16 by mid-afternoon.
- Present
- AQI 35
- UV peak
- 3.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 16
PM × Wind × Precip
PM2.5/PM10 ratio 0.59 with 7 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.59
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- transport
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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 6:22 AM
- Moonset
- 3:12 PM
- In sign
- ♑︎ Capricorn
Pikas hayfeeding in granite peaks
Boulder at a glance
- Today vs. normal: 11°F below the seasonal normal for this latitude
- Last frost: May 23 (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 4, 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 — Boulder
SPC has placed Boulder in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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.