Greeley, Colorado Weather
Thunder retreats as the monsoon dies. Day 93 of summer. Read this microseason across nine climate regions →
Greeley weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 1:50 AM MDT · Open-Meteo
- TodaySep 21Clear——74°51°—
- TuesdaySep 22Overcast35%—82°52°+8°
- WednesdaySep 23Overcast35%—78°58°-4°
- ThursdaySep 24Light Drizzle20%—79°58°+1°
- FridaySep 25Drizzle20%0.11″82°57°+3°
- SaturdaySep 26Overcast12%—84°57°+2°
- SundaySep 27Partly Cloudy14%—85°55°+1°
Air quality now AQI 32 · Good
AQI 32 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±4 points). PM2.5 at 8.7 µg/m³ (AQI 48) with a 0.95 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 8.7 µg/m³ (AQI 48) with a 0.95 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.95
- Wind
- calm
- 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).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:35 PM
- Moonset
- 1:21 AM
- In sign
- ♑︎ Capricorn
Thunder retreats as the monsoon dies
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Greeley at a glance
- Today vs. normal: Today averages 63°F (high 74°F, low 51°F), about the 63°F normal for Sep 21
- Last frost: May 2 (1991–2020 median, NOAA station 6 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots
15-Day Forecast — Greeley
- Mon74°49°6%
- Tue82°52°35%
- Wed78°58°35%
- Thu79°58°20%
- Fri82°57°20%
- Sat84°57°12%
- Sun85°55°14%
- Mon85°59°24%
- Tue83°54°24%
- Wed87°54°11%
- Thu88°68°12%
- Fri75°62°12%
- Sat87°57°22%
- Sun77°53°23%
- Mon80°45°13%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Greeley
Interactive wind and temperature map centered on Greeley — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 8) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, and carrots.
SPC Convective Outlook
Storm Prediction Center — Greeley
SPC includes Greeley in the general thunderstorm area tomorrow — no severe risk, but storms are possible.
- TODAYNONENo severe risk
- 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.
Sun & seasons in Greeley
Greeley sits in Weld County, where the year’s longest day runs 15h 4m of daylight and its shortest just 9h 17m — a swing of +5h 47m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Denver, the state’s largest city, lies about 45 miles to the S. The nearest town Greeley tracks is Timnath, roughly 13 miles to the NW.
Air quality in Greeley
Air quality in Greeley’s county has held roughly steady since 2020; its cleanest year on record was 2022 (median AQI 51). See the full air-quality history for Greeley.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| July | beans, squash, fall brassicas, carrots | lettuce, peas, spinach, beans, summer squash, garlic |
| August | — | tomatoes, peppers, beans, summer squash, winter squash, garlic |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| October | — | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
A year in weather
The year in Greeley tops out in July (~76°F) and dips lowest in December (~31°F), with May wettest at 2.6 inches and February driest at 0.5 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 0.5″ | 4 |
| February | 34° | 0.5″ | 4 |
| March | 44° | 0.9″ | 5 |
| April | 51° | 1.8″ | 8 |
| May | 60° | 2.6″ | 11 |
| June | 70° | 1.8″ | 8 |
| July | 76° | 1.6″ | 7 |
| August | 73° | 1.6″ | 7 |
| September | 65° | 1.1″ | 6 |
| October | 52° | 1.1″ | 6 |
| November | 40° | 0.7″ | 4 |
| December | 31° | 0.6″ | 4 |
Regional context
Similar climates Evans, CO, Garden City, CO, La Salle, CO
Greeley's climate, from NOAA NCEI 1991-2020 station normals, pairs 31°F Januarys with 76°F Julys — a 45°F swing. About 14.7 inches of precipitation falls over roughly 73 days a year.
Precipitation in Greeley runs summer-dominant: May averages 2.6 inches across 10.8 days of warm-season storms, while February drops to 0.5 inches over 4.2 rainy days of drier cool air. That puts Greeley in a summer-convective cohort with places like Evans, CO, Garden City, CO and La Salle, CO.
By May 2 the frosts ease in Greeley, opening the season for peas, lettuce, spinach, and radishes. In Greeley, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Greeley's frost date. Greeley's window closes around October 8 as Greeley's overnight lows return below freezing. In about half of years, Greeley's last freeze comes after May 2.
Similar climates: Evans, CO, Garden City, CO, La Salle, CO, Eaton, CO, Milliken, CO.
Frequently asked
- When does it freeze in Greeley?
- Greeley's last spring frost lands near May 2, and in Greeley the first fall frost follows around October 8.
- What is the rainy season in Greeley?
- Rainfall in Greeley peaks in May near 2.6 inches, out of about 15 inches annually.
- What is the warmest month in Greeley?
- On average July tops the year in Greeley at about 76°F.
- What is the coldest month in Greeley?
- The coldest stretch in Greeley falls in December, around 31°F on average.
- When can I start a vegetable garden in Greeley?
- In Greeley, sow peas and hardy greens around May 2; Greeley's tomatoes and peppers wait two weeks more.
- How many rainy days does Greeley get?
- Expect roughly 73 wet days a year in Greeley.
- What hardiness zone is Greeley?
- With December around 31°F, Greeley's zone reflects that minimum — the USDA ZIP map confirms Greeley's band.
- What is the 10-day forecast for Greeley?
- Greeley'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 Greeley?
- See this week's day-by-day rain chances for Greeley in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Greeley?
- Current conditions for Greeley and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Greeley forecast updated?
- The Greeley forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Greeley?
- Today's sunrise and sunset times for Greeley 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 Greeley?
- The next few days in Greeley's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Greeley sits at 40.4°N; its climate zone is cold semi-arid (Köppen approximation).
ZIP codes in Greeley
- 80631
- 80632
- 80633
- 80634
- 80638
- 80639