Denver, Colorado climate: Normal weather by month, frost dates and records
Denver's normal year runs from 18°F December nights to 90°F July afternoons, with 14.5 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.7°C, December lows of −8°C, July highs of 32°C, 368 mm of precipitation a year.
- NOAA stationDenver International Airport
- Station IDUSW00003017
- Location39.83°N 104.66°W
- Elevation5,414 ft (1,650 m)
- From the center13 miles
- Population729,019
On October 23, the normal high in Denver is 62°F and the normal low 34°F, and the chance of measurable rain or snow is 17%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Denver.
- Jan 45° 19°
- Feb 46° 20°
- Mar 56° 28°
- Apr 62° 34°
- May 71° 44°
- Jun 83° 53°
- Jul 90° 60°
- Aug 88° 58°
- Sep 80° 50°
- Oct 65° 37°
- Nov 53° 26°
- Dec 44° 18°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Denver each month?
July is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 18°F. The most precipitation falls in May (2.16 in), the least in December (0.35 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 45°F | 19°F | 31.7°F | 0.38 | 4 | <1 | 29 | 9 h 40 min |
| February | 46°F | 20°F | 32.7°F | 0.41 | 6 | <1 | 26 | 10 h 40 min |
| March | 56°F | 28°F | 41.6°F | 0.86 | 6 | <1 | 23 | 11 h 50 min |
| April | 62°F | 34°F | 47.8°F | 1.68 | 9 | <1 | 13 | 13 h 10 min |
| May | 71°F | 44°F | 57.4°F | 2.16 | 10 | 1 | 3 | 14 h 20 min |
| June | 83°F | 53°F | 68.2°F | 1.94 | 8 | 9 | <1 | 15 h |
| July | 90°F | 60°F | 75.1°F | 2.14 | 8 | 19 | <1 | 14 h 40 min |
| August | 88°F | 58°F | 72.9°F | 1.58 | 8 | 14 | <1 | 13 h 50 min |
| September | 80°F | 50°F | 64.8°F | 1.35 | 6 | 4 | 1 | 12 h 30 min |
| October | 65°F | 37°F | 51.1°F | 0.99 | 5 | <1 | 9 | 11 h 10 min |
| November | 53°F | 26°F | 39.4°F | 0.64 | 5 | <1 | 23 | 10 h |
| December | 44°F | 18°F | 31.2°F | 0.35 | 4 | <1 | 29 | 9 h 20 min |
| Year (annual) | 65°F | 37°F | 51.2°F | 14.48 | 80 | 46 | 156 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 7°C | −7°C | −0.2°C | 10 mm |
| February | 8°C | −7°C | 0.4°C | 10 mm |
| March | 13°C | −2°C | 5.3°C | 22 mm |
| April | 17°C | 1°C | 8.8°C | 43 mm |
| May | 22°C | 6°C | 14.1°C | 55 mm |
| June | 29°C | 12°C | 20.1°C | 49 mm |
| July | 32°C | 16°C | 23.9°C | 54 mm |
| August | 31°C | 15°C | 22.7°C | 40 mm |
| September | 26°C | 10°C | 18.2°C | 34 mm |
| October | 19°C | 3°C | 10.6°C | 25 mm |
| November | 12°C | −3°C | 4.1°C | 16 mm |
| December | 7°C | −8°C | −0.4°C | 9 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Denver's own co-op station Denver-Stapleton does: 49 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003017; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Denver?
Normal highs sit between 65°F and 85°F in May, June, September and October. Of those, October has the fewest days with rain (5).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003017.
When is the last frost in Denver?
In Denver, the last spring frost (32°F) comes after May 5 in half of years and after May 19 in one year in ten; the first autumn frost comes before October 9 in half of years and before September 27 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 51 year in 10 after May 19; 9 in 10 after April 23
- First autumn frost, half of years before
- October 91 year in 10 before September 27; 9 in 10 before October 20
NOAA puts the median frost-free season at 156 days, and the season without a hard freeze (28°F) at 174 days.
A hard freeze (28°F) comes after April 25 in half of springs and before October 18 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Denver in zone 6a across its 30 ZIP code areas (6a in 80249, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Denver's NOAA station is in zone 5b: the coldest night of a typical year reaches −12°F (25 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00003017; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Denver ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Denver's 30 ZIP code areas are all in zone 6a. Each ZIP's frost dates are in the frost tool.
| ZIP code | Zone | Land in Denver |
|---|---|---|
| 80123 | 6a | 5.9 km² |
| 80202 | 6a | 3.0 km² |
| 80203 | 6a | 2.8 km² |
| 80204 | 6a | 14.2 km² |
| 80205 | 6a | 12.0 km² |
| 80206 | 6a | 6.4 km² |
| 80207 | 6a | 10.2 km² |
| 80209 | 6a | 9.1 km² |
| 80210 | 6a | 15.8 km² |
| 80211 | 6a | 11.7 km² |
| 80212 | 6a | 6.9 km² |
| 80216 | 6a | 18.9 km² |
| 80218 | 6a | 4.1 km² |
| 80219 | 6a | 19.1 km² |
| 80220 | 6a | 13.3 km² |
| 80221 | 6a | 2.7 km² |
| 80222 | 6a | 8.4 km² |
| 80223 | 6a | 13.7 km² |
| 80224 | 6a | 8.3 km² |
| 80227 | 6a | 4.0 km² |
| 80230 | 6a | 6.5 km² |
| 80231 | 6a | 7.4 km² |
| 80235 | 6a | 2.2 km² |
| 80236 | 6a | 8.0 km² |
| 80237 | 6a | 9.4 km² |
| 80238 | 6a | 17.6 km² |
| 80239 | 6a | 21.4 km² |
| 80246 | 6a | 2.9 km² |
| 80247 | 6a | 4.1 km² |
| 80249 | 6a | 123.4 km² |
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Denver?
In a normal year in Denver, 46 days a year reach 90°F (2 of them 100°F or more), 156 nights fall to 32°F or colder and 80 days bring measurable precipitation.
- Days at 90°F or more
- 46a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 156a normal year
- Days that stay below freezing
- 22high of 32°F or less
- Days with 0.01 inch of precipitation
- 80a normal year
The highest temperature in Denver's official record (kept by the National Weather Service since 1872) is 105°F, on June 26, 2012; the lowest is −29°F, on January 9, 1875.
The wettest calendar year on that record is 1967, with 23.31 in; the snowiest season is 1908–09, with 118.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00003017; records: ACIS (NOAA Regional Climate Centers), NWS threaded record DENthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Denver, and how clear are its skies?
The summer (June-August) dew point averages 47°F. The muggiest month is July, with an average dew point of 50°F; the driest air comes in December (14°F). March is the windiest month (11.3 mph on average), and September has the most clear or nearly clear hours (34%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 15°F | 53% | 36% | 9.7 mph | – | – |
| February | 15°F | 47% | 28% | 10.6 mph | – | – |
| March | 24°F | 47% | 27% | 11.3 mph | 20% | 17% |
| April | 32°F | 49% | 30% | 11.0 mph | 18% | 23% |
| May | 42°F | 50% | 30% | 10.3 mph | 19% | 13% |
| June | 46°F | 41% | 22% | 10.0 mph | 34% | 5% |
| July | 50°F | 47% | 27% | 9.3 mph | 19% | 7% |
| August | 45°F | 42% | 23% | 9.5 mph | 29% | 6% |
| September | 35°F | 44% | 24% | 9.4 mph | 34% | 11% |
| October | 25°F | 47% | 28% | 9.5 mph | – | – |
| November | 17°F | 49% | 33% | 9.6 mph | 24% | 13% |
| December | 14°F | 52% | 38% | 9.6 mph | – | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00003017. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Denver?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Denver, 4.8 kWh per square metre a day. September is the sunniest month (85%) and May the cloudiest (76%). Among the 459 U.S. places of 50,000 or more, that ranks tied 125th (with 50 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 2.6 |
| February | 78% | 3.5 |
| March | 78% | 4.7 |
| April | 76% | 5.8 |
| May | 76% | 6.5 |
| June | 82% | 7.2 |
| July | 83% | 7.0 |
| August | 84% | 6.3 |
| September | 85% | 5.4 |
| October | 82% | 4.0 |
| November | 81% | 2.9 |
| December | 79% | 2.3 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Denver need?
A normal year in Denver brings 5,862 heating degree days, 9% more than the median U.S. place (5,373), and 850 cooling degree days, 6% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,044 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,034 | 0 |
| February | 904 | 0 |
| March | 726 | 0 |
| April | 517 | 1 |
| May | 261 | 26 |
| June | 52 | 147 |
| July | 4 | 315 |
| August | 9 | 254 |
| September | 105 | 99 |
| October | 436 | 7 |
| November | 767 | 0 |
| December | 1,048 | 0 |
| Year (annual) | 5,862 | 850 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003017. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Denver been warmer than normal lately?
2025 averaged 52.8°F, 1.6°F above the 1991-2020 normal of 51.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 52.7°F | +1.5°F | 12.53 |
| 2022 | 51.4°F | +0.2°F | 11.92 |
| 2023 | 51.0°F | −0.2°F | 18.94 |
| 2024 | 53.9°F | +2.7°F | 14.12 |
| 2025 | 52.8°F | +1.6°F | 15.38 |
Over 30 complete years from 1996 to 2025, the station's annual mean temperature rose at a fitted 4.3°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00003017; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Denver's climate compare?
Denver is warmer than 93 of the other 124 places with their own NOAA record in Colorado, and wetter than 45. Across the 7,247 U.S. stations with normals, its annual mean of 51.2°F is warmer than 46%.
In the Köppen classification computed from these normals, Denver is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Denver share this climate record?
3 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Bennett, CO3,916 people · 14 mi SE
- Aetna Estates, CO1,177 people · 7 mi S
- Watkins, CO1,087 people · 10 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Denver's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Denver. This page uses Denver International Airport; the others differ by site and elevation, and the linked ones have pages of their own:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Denver Water Dept USC00052223 | 7 mi W | 5,228 ft | 53.3°F | 21°F | 91°F | 15.8 | 41 | April 30 |
| Denver-Stapleton USW00023062 | 1 mi E | 5,286 ft | 51.3°F | 18°F | 90°F | 15.4 | 49 | May 4 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Denver's climate
What is the coldest month in Denver?
December, with a normal high of 44°F and a normal low of 18°F. The warmest is July (90°F by day, 60°F at night).
Does it snow in Denver?
Yes. NOAA publishes no 1991-2020 snowfall normal for Denver's NOAA station; Denver's own co-op station Denver-Stapleton records 49 inches of snow in a normal year.
What is the rainiest month in Denver?
May, with 2.16 in of precipitation in a normal year; the driest is December with 0.35 in.
What plant hardiness zone is Denver in?
The USDA's 2023 map puts Denver in zone 6a across its 30 ZIP code areas (6a in 80249, the largest). By the same method at Denver's NOAA station, the coldest night of a typical year reaches −12°F (25 years, 1991-2020): zone 5b.
How late can frost come in Denver?
In half of years the last 32°F night comes after May 5; in one year in ten it comes after May 19. Waiting until May 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Denver in OctoberThis month day by day, its records and recent years
- Colorado climateThe statewide normals and every place in the state
- Brighton, CO12 miles from this station, 50.6°F a year
- Cherry Creek, CO17 miles from this station, 50.8°F a year
- Northglenn, CO19 miles from this station, 52.4°F a year
- Denver Water Dept, CO20 miles from this station, 53.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made