Longmont in Winter
In winter (December, January and February), Longmont sees average daytime highs around 42°F and overnight lows near 19°F, with 2.2 in of precipitation over about 15 wet days across the season. It is the coldest season of the year and the driest season of the year.
Over the season highs climb from about 44°F in early December to 47°F by late February. The sky is clear or mostly clear about 46% of the time across winter, and the air most often feels dry.
Winter is Longmont's weakest season of the year to visit on our travel score. For the whole year in context, see Longmont's year-round climate.
- Avg daytime high
- 42°F
- coldest season of the year
- Avg overnight low
- 19°F
- Precipitation
- 2.2 in
- 15 wet days
- Avg wind
- 4 mph
- Travel score
- 0.4
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Longmont in Winter
Over the season highs climb from about 44°F in early December to 47°F by late February.
A typical winter day in Longmont reaches about 42°F and drops to 19°F overnight. The warmest of the three months is February, the coolest January.
How winter really feels in Longmont
Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 90 that feel at or below 32°F.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Longmont weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 41° / 18° | 0.8 | 4.7 | 4.5 | 9.5 | 0.1 |
| Feb | 44° / 20° | 0.8 | 5.3 | 5 | 10.4 | 1.0 |
| Mar | 54° / 27° | 1.6 | 7.3 | 4.4 | 11.7 | 3.6 |
| Apr | 61° / 35° | 2.6 | 9.5 | 4 | 13 | 5.0 |
| May | 69° / 44° | 3.4 | 11.7 | 0.6 | 14.2 | 6.2 |
| Jun | 80° / 53° | 2.1 | 8.5 | 0 | 14.8 | 6.6 |
| Jul | 86° / 59° | 1.7 | 7.4 | 0 | 14.6 | 5.3 |
| Aug | 84° / 57° | 1.6 | 6.8 | 0 | 13.6 | 6.1 |
| Sep | 76° / 49° | 1.5 | 5.9 | 0.4 | 12.3 | 7.6 |
| Oct | 63° / 37° | 1.6 | 6.5 | 1.9 | 10.9 | 6.2 |
| Nov | 50° / 27° | 1.1 | 5.8 | 4.4 | 9.8 | 2.7 |
| Dec | 41° / 19° | 0.7 | 4.5 | 4.4 | 9.2 | 0.2 |
Cloud cover in Winter
The sky is clear or mostly clear about 46% of the time across winter.
Chance of precipitation in Winter
Longmont gets around 2.2 in of rain and snow over 15 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 4 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 24 min in early December to 11 hours by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 3.0 kWh/m².
Is winter a good time to visit Longmont?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Longmont.
What to pack for Longmont in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Longmont sees daytime highs around 42°F and nights near 19°F. Pack a warm layer and a heavy coat. About 15 days see rain.
UV index in Longmont in Winter
Clear-sky midday UV across winter averages around 3. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Longmont peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 7 | 6 | 7 | 11 | 11 | 10 | 7 | 5 | 3 | 2 |
| Level | Moderate | Moderate | High | High | Very high | Extreme | Extreme | Very high | Very high | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 7 | High |
| Apr | 6 | High |
| May | 7 | Very high |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 10 | Very high |
| Sep | 7 | Very high |
| Oct | 5 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Longmont in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Longmont is worst in October — around 30 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (November, 10 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 12 | 12 | 14 | 11 | 11 | 12 | 14 | 19 | 17 | 30 | 10 | 11 |
| Level | Good | Moderate | Moderate | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 12 | Good |
| Feb | 12 | Moderate |
| Mar | 14 | Moderate |
| Apr | 11 | Good |
| May | 11 | Good |
| Jun | 12 | Good |
| Jul | 14 | Moderate |
| Aug | 19 | Moderate |
| Sep | 17 | Moderate |
| Oct | 30 | Moderate |
| Nov | 10 | Good |
| Dec | 11 | Good |
Where is Longmont?
Longmont sits at 40.2°N, 105.1°W, 4,984 ft above sea level, in United States. The nearest listed city is Erie, 8.7 mi away.
Topography around Longmont
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Longmont.
Within 2 miles, the terrain around Longmont has only modest variations in elevation — a maximum elevation change of 197 ft around an average of 4,993 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,765 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,721 ft.
The land around Longmont is covered by artificial surfaces (50%) and trees (22%) within 2 miles, grassland (54%) and cropland (25%) within 10 miles, and grassland (42%) and trees (31%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Longmont (40.1672°, -105.1019°, elevation 4,984 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.