Keystone, Colorado Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Keystone weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——64°40°—
- FridayJun 5Overcast——66°44°+2°
- SaturdayJun 6Light Drizzle51%0.03″71°43°+5°
- SundayJun 7Overcast——65°40°-6°
- MondayJun 8Overcast23%—68°39°+3°
- TuesdayJun 9Overcast13%—70°40°+2°
- WednesdayJun 10Drizzle17%0.08″67°42°-3°
Ozone at AQI 73 now. AQI up 5 over the last 6 hours (gradual rise). With UV 8.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 57 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 73 now. With UV 8.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 57 by mid-afternoon.
- Present
- AQI 73
- UV peak
- 8.3 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 57
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
- 5:33 AM
- Moonset
- 3:10 PM
- In sign
- ♒︎ Aquarius
Pikas hayfeeding in granite peaks
Keystone at a glance
- Today vs. normal: 15°F below the seasonal normal for this latitude
- Last frost: April 14 (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 — Keystone
SPC has placed Keystone 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.