Windsor, Colorado Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Windsor weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——90°48°—
- FridayJun 5Partly Cloudy——91°56°+1°
- SaturdayJun 6Heavy Drizzle—0.01″97°57°+6°
- SundayJun 7Light Drizzle——96°59°-1°
- MondayJun 8Overcast23%—95°61°-1°
- TuesdayJun 9Overcast——101°62°+6°
- WednesdayJun 10Light Drizzle——100°65°-1°
Ozone at AQI 86 now. AQI flat over the last 6 hours (within ±3 points). With UV 8.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 65 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 86 now. With UV 8.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 65 by mid-afternoon.
- Present
- AQI 86
- UV peak
- 8.0 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 65
PM × Wind × Precip
PM2.5/PM10 ratio 0.57 with 7 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.57
- 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
- 5:32 AM
- Moonset
- 3:03 PM
- In sign
- ♒︎ Aquarius
Pikas hayfeeding in granite peaks
Windsor at a glance
- Today vs. normal: 15°F above the seasonal normal for this latitude
- Last frost: April 19 (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 — Windsor
SPC has placed Windsor in the General Thunderstorms category for severe thunderstorms today.
- TODAYTSTMGeneral Thunderstorms
- 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.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Windsor's warmest month is July (~73°F mean) and its coldest is December (~31°F). Rainfall peaks in May (2.7 inches) and bottoms out in January (0.4 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 32° | 0.4″ | 2 |
| February | 34° | 0.5″ | 2 |
| March | 42° | 1.3″ | 3 |
| April | 49° | 2.1″ | 5 |
| May | 58° | 2.7″ | 6 |
| June | 67° | 1.9″ | 4 |
| July | 73° | 1.6″ | 4 |
| August | 71° | 1.4″ | 3 |
| September | 63° | 1.4″ | 3 |
| October | 50° | 1.3″ | 3 |
| November | 39° | 0.7″ | 2 |
| December | 31° | 0.5″ | 2 |
Regional context
Windsor sits within a cold semi-arid climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Fort Collins, CO, Greeley, CO, Boulder, CO, Longmont, CO, Loveland, CO.
Frequently asked
- When does it freeze in Windsor?
- Windsor's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Windsor?
- May is the wettest month with about 2.7 inches of rain on average; the city receives roughly 16 inches annually.
- What is the warmest month in Windsor?
- July is typically warmest, averaging about 73°F.
- What is the coldest month in Windsor?
- December is typically coldest, averaging about 31°F.
- When can I start a vegetable garden in Windsor?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Windsor get?
- Windsor averages about 37 rainy days per year.
- What hardiness zone is Windsor?
- Windsor's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Windsor, Colorado sits in a cold semi-arid climate zone. January means hover near 32°F while July averages 73°F — a 41°F seasonal swing.
Across the year, Windsor receives about 16 inches of precipitation spread over roughly 37 rainy days.
The rhythm of the year is set by latitude (40.5°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.