Fort Collins, Colorado Weather
Monsoon storms drench the south. Day 15 of summer. Read this microseason across nine climate regions →
Fort Collins weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast20%—92°56°—
- SundayJul 5Overcast——96°58°+4°
- MondayJul 6Overcast——100°62°+4°
- TuesdayJul 7Drizzle42%—89°73°-11°
- WednesdayJul 8Light Rain61%0.09″94°66°+5°
- ThursdayJul 9Overcast42%—101°67°+7°
- FridayJul 10Light Drizzle12%—91°65°-10°
AQI 88 (Moderate), driven by Ozone. AQI up 16 in the last 6 hours — air quality is degrading. Ozone at AQI 47 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 11 around 1 PM.
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 47 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 11 around 1 PM.
- Present
- AQI 47
- UV peak
- 0.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 11
PM × Wind × Precip
PM2.5 at 7.7 µg/m³ (AQI 43) with a 0.81 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.81
- 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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:19 PM
- Moonset
- 11:15 AM
- In sign
- ♓︎ Pisces
Monsoon storms drench the south
Fort Collins at a glance
- Today vs. normal: 5°F above the seasonal normal for this latitude
- Last frost: April 19 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP codes: 80521, 80524, 80525, 80526, 80528
16-Day Forecast — Fort Collins
- Sat92°56°20%
- Sun96°58°2%
- Mon100°62°3%
- Tue89°73°42%
- Wed94°66°61%
- Thu101°67°42%
- Fri91°65°12%
- Sat95°64°4%
- Sun101°70°2%
- Mon107°72°7%
- Tue106°78°14%
- Wed106°78°25%
- Thu106°80°33%
- Fri97°77°39%
- Sat105°74°39%
- Sun93°69°45%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Fort Collins
Right now in the garden
Peak growing season
As of July 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Fort Collins
SPC includes Fort Collins in the general thunderstorm area today — no severe risk, but storms are possible.
- 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.
Microseason · July 1–5
Monsoon storms drench the south
Monsoon established in southern Mountain West (New Mexico, southern Utah, Arizona north); afternoon downpours and lightning common.
Day 186 of 365 · Wedge 37 of 72
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
Fort Collins'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
Fort Collins's climate, from NOAA NCEI 1991-2020 station normals, pairs 32°F Januarys with 73°F Julys — a 41°F swing. About 15.9 inches of precipitation falls over roughly 37 days a year.
Precipitation in Fort Collins runs summer-dominant: May averages 2.7 inches across 5.8 days of warm-season storms, while January drops to 0.4 inches over 1.6 rainy days of drier cool air. That puts Fort Collins in a summer-convective cohort with places like Timnath, CO, Laporte, CO and Loveland, CO.
The cool-season window in Fort Collins starts at mid-April, when nights stop freezing — think peas, lettuce, spinach, and radishes. In Fort Collins, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Fort Collins's frost date. Fort Collins's window closes around mid-November as overnight lows return below freezing. Within Fort Collins, cold-air pooling chills low spots by 5-10°F, shifting Fort Collins's local frost dates.
Similar climates: Timnath, CO, Laporte, CO, Loveland, CO, Windsor, CO, Severance, CO.
Naturalist notes
Late May brings the return of broad-tailed hummingbirds to Fort Collins gardens and mountain meadows.
Ponderosa pine trees begin releasing their pollen around mid-May, dusting surfaces with yellow powder.
Frequently asked
- When does it freeze in Fort Collins?
- Fort Collins's last spring frost lands near mid-April, and in Fort Collins the first fall frost follows around mid-November.
- What is the rainy season in Fort Collins?
- May is the wettest month in Fort Collins, about 2.7 inches on average; the year totals roughly 16 inches.
- What is the warmest month in Fort Collins?
- On average July tops the year in Fort Collins at about 73°F.
- What is the coldest month in Fort Collins?
- The coldest stretch in Fort Collins falls in December, around 31°F on average.
- When can I start a vegetable garden in Fort Collins?
- In Fort Collins, sow peas and hardy greens around mid-April; Fort Collins's tomatoes and peppers wait two weeks more.
- How many rainy days does Fort Collins get?
- Fort Collins records around 37 days of measurable precipitation annually.
- What hardiness zone is Fort Collins?
- Since December in Fort Collins averages 31°F, Fort Collins's USDA zone follows that floor — confirm it by ZIP.
- What is the 10-day forecast for Fort Collins?
- Fort Collins's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Fort Collins?
- See this week's day-by-day rain chances for Fort Collins in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Fort Collins?
- Current conditions for Fort Collins and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Fort Collins forecast updated?
- The Fort Collins forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Fort Collins?
- Today's sunrise and sunset times for Fort Collins are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Fort Collins?
- The next few days in Fort Collins's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Set in a cold semi-arid zone, Fort Collins, Colorado swings from 32°F in the heart of winter to 73°F at midsummer — a 41°F arc.
Yearly precipitation in Fort Collins totals around 16 inches, spread over about 37 days of rain or snow.
Fort Collins sits at 40.5°N; that 41°F seasonal swing frames planting windows and frost dates across Fort Collins.
ZIP codes in Fort Collins
- 80528
- 80521
- 80526
- 80524
- 80525
- 80523
- 80527
- 80553