Nunn, Colorado climate: Normal weather by month, frost dates and records
Nunn's normal year runs from 14°F December nights to 87°F July afternoons, with 13.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.5°C, December lows of −10°C, July highs of 31°C, 340 mm of precipitation a year.
- NOAA stationNunn (7 mi NNE)
- Station IDUSW00094074
- Location40.81°N 104.76°W
- Elevation5,390 ft (1,643 m)
- Population533
On October 23, the normal high in Nunn is 59°F and the normal low 29°F, and the chance of measurable rain or snow is 19%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Nunn.
- Jan 42° 14°
- Feb 44° 15°
- Mar 53° 23°
- Apr 60° 30°
- May 69° 40°
- Jun 80° 48°
- Jul 87° 54°
- Aug 85° 53°
- Sep 76° 44°
- Oct 62° 32°
- Nov 50° 21°
- Dec 41° 14°
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 Nunn each month?
July is the warmest month, with normal highs of 87°F; December the coldest, with normal lows of 14°F. The most precipitation falls in May (2.47 in), the least in January (0.25 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 42°F | 14°F | 27.9°F | 0.25 | 3 | <1 | 31 | 9 h 30 min |
| February | 44°F | 15°F | 29.6°F | 0.38 | 6 | <1 | 28 | 10 h 40 min |
| March | 53°F | 23°F | 37.9°F | 0.82 | 6 | <1 | 28 | 11 h 50 min |
| April | 60°F | 30°F | 44.6°F | 1.62 | 10 | <1 | 19 | 13 h 20 min |
| May | 69°F | 40°F | 54.1°F | 2.47 | 13 | <1 | 5 | 14 h 30 min |
| June | 80°F | 48°F | 64.0°F | 1.94 | 10 | 6 | <1 | 15 h |
| July | 87°F | 54°F | 70.6°F | 1.62 | 10 | 15 | <1 | 14 h 50 min |
| August | 85°F | 53°F | 69.0°F | 1.33 | 8 | 11 | <1 | 13 h 50 min |
| September | 76°F | 44°F | 60.3°F | 1.11 | 8 | 3 | 1 | 12 h 30 min |
| October | 62°F | 32°F | 47.1°F | 1.00 | 7 | <1 | 15 | 11 h 10 min |
| November | 50°F | 21°F | 35.6°F | 0.56 | 5 | <1 | 27 | 10 h |
| December | 41°F | 14°F | 27.4°F | 0.30 | 5 | <1 | 31 | 9 h 20 min |
| Year (annual) | 63°F | 32°F | 47.3°F | 13.40 | 89 | 34 | 183 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −10°C | −2.3°C | 6 mm |
| February | 7°C | −9°C | −1.3°C | 10 mm |
| March | 12°C | −5°C | 3.3°C | 21 mm |
| April | 15°C | −1°C | 7.0°C | 41 mm |
| May | 20°C | 4°C | 12.3°C | 63 mm |
| June | 27°C | 9°C | 17.8°C | 49 mm |
| July | 31°C | 12°C | 21.4°C | 41 mm |
| August | 30°C | 11°C | 20.6°C | 34 mm |
| September | 25°C | 7°C | 15.7°C | 28 mm |
| October | 17°C | 0°C | 8.4°C | 25 mm |
| November | 10°C | −6°C | 2.0°C | 14 mm |
| December | 5°C | −10°C | −2.6°C | 8 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Fort Collins (4 mi E) (21 miles away), gets 48 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094074; 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 Nunn?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (8).
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 USW00094074.
When is the last frost in Nunn?
In Nunn, the last spring frost (32°F) comes after May 13 in half of years and after May 27 in one year in ten; the first autumn frost comes before September 27 in half of years and before September 14 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 131 year in 10 after May 27; 9 in 10 after May 2
- First autumn frost, half of years before
- September 271 year in 10 before September 14; 9 in 10 before October 9
NOAA puts the median frost-free season at 136 days, and the season without a hard freeze (28°F) at 156 days.
A hard freeze (28°F) comes after May 4 in half of springs and before October 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Nunn in zone 5b in ZIP code 80650, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Nunn's NOAA station is in zone 5a: the coldest night of a typical year reaches −17°F (17 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 USW00094074; 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.
How hot and how cold does it get in Nunn?
In a normal year in Nunn, 34 days a year reach 90°F (1 of them 100°F or more), 183 nights fall to 32°F or colder and 89 days bring measurable precipitation.
- Days at 90°F or more
- 34a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 183a normal year
- Days that stay below freezing
- 26high of 32°F or less
- Days with 0.01 inch of precipitation
- 89a normal year
The highest temperature in this station's record (since 2003) is 103°F, on July 18, 2022; the lowest is −29°F, on January 15, 2024.
The wettest calendar year on that record is 2023, with 18.63 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00094074; records: ACIS (NOAA Regional Climate Centers), station USW00094074. Records use complete months only; a month missing more than three days is left out.
How sunny is Nunn?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Nunn, 4.7 kWh per square metre a day. September is the sunniest month (85%) and April the cloudiest (75%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 77% | 2.4 |
| February | 76% | 3.3 |
| March | 78% | 4.6 |
| April | 75% | 5.6 |
| May | 75% | 6.3 |
| June | 83% | 7.3 |
| July | 84% | 7.0 |
| August | 84% | 6.2 |
| September | 85% | 5.2 |
| October | 80% | 3.8 |
| November | 79% | 2.7 |
| December | 76% | 2.1 |
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 Nunn need?
A normal year in Nunn brings 6,845 heating degree days, 27% more than the median U.S. place (5,373), and 434 cooling degree days, 52% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,280 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,150 | 0 |
| February | 993 | 0 |
| March | 840 | 0 |
| April | 612 | 0 |
| May | 345 | 6 |
| June | 91 | 61 |
| July | 10 | 182 |
| August | 26 | 149 |
| September | 176 | 35 |
| October | 555 | 1 |
| November | 881 | 0 |
| December | 1,165 | 0 |
| Year (annual) | 6,845 | 434 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094074. 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 Nunn been warmer than normal lately?
2025 averaged 49.0°F, 1.7°F above the 1991-2020 normal of 47.3°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 48.2°F | +0.9°F | 15.67 |
| 2022 | 47.4°F | +0.1°F | 8.82 |
| 2023 | 47.6°F | +0.3°F | 18.63 |
| 2024 | 49.5°F | +2.2°F | 8.81 |
| 2025 | 49.0°F | +1.7°F | 10.60 |
Source: observed years: ACIS, station USW00094074. A year counts only with all twelve months complete.
How does Nunn's climate compare?
Nunn is warmer than 52 of the other 124 places with their own NOAA record in Colorado, and wetter than 32. Across the 7,247 U.S. stations with normals, its annual mean of 47.3°F is warmer than 29%.
In the Köppen classification computed from these normals, Nunn 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 Nunn share this climate record?
Pierce has no NOAA station with 1991-2020 normals of its 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.
- Pierce, CO1,087 people · 11 mi S
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Nunn's climate
What is the coldest month in Nunn?
December, with a normal high of 41°F and a normal low of 14°F. The warmest is July (87°F by day, 54°F at night).
Does it snow in Nunn?
Yes. NOAA publishes no 1991-2020 snowfall normal for Nunn's NOAA station; the nearest record that keeps one, Fort Collins (4 mi E) (21 miles away), records 48 inches of snow in a normal year.
What is the rainiest month in Nunn?
May, with 2.47 in of precipitation in a normal year; the driest is January with 0.25 in.
What plant hardiness zone is Nunn in?
The USDA's 2023 map puts Nunn in zone 5b in ZIP code 80650, the nearest ZIP area. By the same method at Nunn's NOAA station, the coldest night of a typical year reaches −17°F (17 years, 1991-2020): zone 5a.
How late can frost come in Nunn?
In half of years the last 32°F night comes after May 13; in one year in ten it comes after May 27. Waiting until May 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Fort Collins (4 mi E), CO21 miles from this station, 49.3°F a year
- Fort Collins, CO24 miles from this station, 50.7°F a year
- Cheyenne, WY24 miles from this station, 46.9°F a year
- Archer, WY24 miles from this station, 46.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made