Niwot, Colorado Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Niwot weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——91°52°—
- FridayJun 5Overcast——88°63°-3°
- SaturdayJun 6Heavy Drizzle——95°58°+7°
- SundayJun 7Overcast——93°57°-2°
- MondayJun 8Overcast31%—95°56°+2°
- TuesdayJun 9Overcast10%—99°59°+4°
- WednesdayJun 10Overcast——99°63°0°
Ozone at AQI 71 now. AQI flat over the last 6 hours (within ±3 points). With UV 9.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 88 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 71 now. With UV 9.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 88 by mid-afternoon.
- Present
- AQI 71
- UV peak
- 9.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 88
PM × Wind × Precip
PM2.5 at 6.0 µg/m³, PM10 at 10.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.56
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- background
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
- 5:31 AM
- Moonset
- 3:05 PM
- In sign
- ♒︎ Aquarius
Pikas hayfeeding in granite peaks
Niwot at a glance
- Today vs. normal: 12°F above the seasonal normal for this latitude
- Last frost: April 17 (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 — Niwot
SPC has placed Niwot in the General Thunderstorms category for severe thunderstorms today.
- TODAYTSTMGeneral Thunderstorms
- TOMORROWTSTMGeneral Thunderstorms
- 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.