Photo: Matthew Trump · CC BY-SA 3.0Nunn’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 89°, a January night drops to 15°, and about 48 inches of snow falls in a normal winter.
A year in Nunn at a glance
Each month’s typical high and low, and what it brings.
What stands out about Nunn’s climate
Compared with towns across the U.S., with Nunn’s place in Colorado beside it.
What a year in Nunn feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 136 frost-free days a year
In half of years the last 32° night comes by May 13 and the first by September 27. Frost and day counts come from NOAA’s station at Nunn 7 Nne, CO, 7 miles from the town’s center, 180 ft higher.
The 2023 USDA map puts Nunn’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −15°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 48 inches of snow a winter
Snow, measured at Ft Collins 4 E, CO, falls mostly in March and November. Precipitation (rain plus melted snow) adds up to 13 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 82 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Nunn
94% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Nunn 7 Nne, CO.
Living with Nunn’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
136 frost-free days in zone 5b. The last frost comes by May 13 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 27.
Months with highs of 62–84° and lows of 40° or more: May, June and September.
Parks & trails →Of the yearly building losses FEMA expects in Nunn from natural hazards, hail is the largest share (33%); heat waves, cold waves, winter storms and ice storms together are 25%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Nunn and similar climates
TownRatings has no climate map of the towns around Nunn yet.
Climates most like Nunn’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Nunn, CO | 15° | 89° | 13" | 48" |
| Billings, MT | 15° | 89° | 14" | 48" |
| Spring Creek, NV | 15° | 89° | 14" | 41" |
| Preston, ID | 14° | 89° | 15" | 52" |
| Hyde Park, UT | 14° | 89° | 16" | 44" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Nunn averaged 2.1° warmer than the 1900s. The biggest change is in March (+4.2°).
A bigger shift than in 92% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Nunn compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Nunn’s place among Colorado’s.
Nunn weather by month
Highs, lows and precipitation from NOAA’s grid at Nunn’s center; snow, wet days and snow on the ground from Ft Collins 4 E, CO. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 43° | 15° | 0.2" | 6.6" | 4 | 13 | 19° – 35° |
| February | 45° | 17° | 0.3" | 7.0" | 5 | 8 | 26° – 38° |
| March | 55° | 25° | 0.7" | 8.2" | 6 | 4 | 33° – 47° |
| April | 61° | 31° | 1.5" | 5.7" | 9 | 2 | 40° – 52° |
| May | 70° | 41° | 2.2" | 1.8" | 11 | 0 | 49° – 60° |
| June | 82° | 50° | 1.8" | 0.0" | 8 | 0 | 61° – 72° |
| July | 89° | 57° | 1.9" | 0.0" | 8 | 0 | 68° – 76° |
| August | 86° | 54° | 1.6" | 0.0" | 8 | 0 | 66° – 73° |
| September | 78° | 46° | 1.2" | 0.6" | 7 | 0 | 57° – 66° |
| October | 64° | 33° | 1.1" | 4.0" | 6 | 1 | 41° – 54° |
| November | 51° | 23° | 0.5" | 7.6" | 5 | 4 | 29° – 43° |
| December | 42° | 15° | 0.3" | 6.9" | 4 | 11 | 21° – 34° |
| Year | 64° | 34° | 13.3" | 48.4" | 82 | 44 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 19° to 35°. August is the most reliable, staying within 8°.
Where Nunn’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Nunn’s center.
- Snow: Ft Collins 4 E, CO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Nunn 7 Nne, CO, 7 miles from the town’s center, 180 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Nunn’s climate
What is the weather like in Nunn?
A typical July afternoon reaches 89°, a January night drops to 15°, and about 48 inches of snow falls in a normal winter. Colder January nights than 85% of U.S. towns; hotter July afternoons than 72% of U.S. towns.
How cold does it get in Nunn in winter?
January nights average 15°. About 183 nights a year reach 32° or below and 12 reach 0° or below. In the coldest January of the last 30 years the month averaged 19°.
How much snow does Nunn get?
About 48 inches in a normal winter at Ft Collins 4 E, CO, most of it in March and November, with snow on the ground about 44 days a year.
How hot does it get in Nunn?
July, with a typical high of 89° and a low of 57°. About 34 days a year reach 90° (Nunn 7 Nne, CO).
When is the first and last frost in Nunn?
In half of years the last spring frost (32°) comes by May 13 and the first fall frost by September 27, about 136 frost-free days, at Nunn 7 Nne, CO.
What growing zone is Nunn in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −15°.
What is the best time of year to visit Nunn?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Nunn getting warmer?
Yes: 1991–2020 averaged 2.1° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 92% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Nunn.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.