Fort Collins in Summer
In summer (June, July and August), Fort Collins sees average daytime highs around 83°F and overnight lows near 56°F, with 5.3 in of rain over about 23 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Over the season highs climb from about 75°F in early June to 82°F by late August. The sky is clear or mostly clear about 37% of the time across summer, and the air most often feels dry.
Summer is Fort Collins's best season of the year to visit on our travel score. For the whole year in context, see Fort Collins's year-round climate.
- Avg daytime high
- 83°F
- warmest season of the year
- Avg overnight low
- 56°F
- Rainfall
- 5.3 in
- 23 wet days
- Avg wind
- 4 mph
- Travel score
- 6.1
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Fort Collins in Summer
Over the season highs climb from about 75°F in early June to 82°F by late August.
A typical summer day in Fort Collins reaches about 83°F and drops to 56°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Fort Collins
Once humidity and wind are folded in, summer brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Fort Collins weather by month
How the three summer months (June, July and August) 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° / 19° | 0.6 | 4 | 4.2 | 9.4 | 0.1 |
| Feb | 44° / 20° | 0.7 | 4.9 | 4.6 | 10.4 | 0.9 |
| Mar | 53° / 27° | 1.5 | 6.9 | 4.3 | 11.7 | 3.4 |
| Apr | 60° / 34° | 2.5 | 9.6 | 3.7 | 13 | 4.9 |
| May | 69° / 43° | 3.4 | 11.6 | 0.7 | 14.2 | 6.1 |
| Jun | 79° / 52° | 2.1 | 8.7 | 0 | 14.8 | 6.7 |
| Jul | 86° / 58° | 1.7 | 7.7 | 0 | 14.6 | 5.5 |
| Aug | 84° / 57° | 1.5 | 6.7 | 0 | 13.6 | 6.2 |
| Sep | 76° / 49° | 1.5 | 5.8 | 0.3 | 12.3 | 7.6 |
| Oct | 63° / 37° | 1.6 | 6.9 | 2 | 10.9 | 6.0 |
| Nov | 50° / 27° | 1.0 | 5.3 | 4.2 | 9.7 | 2.6 |
| Dec | 41° / 20° | 0.6 | 3.8 | 4 | 9.2 | 0.2 |
Cloud cover in Summer
The sky is clear or mostly clear about 37% of the time across summer.
Chance of precipitation in Summer
Fort Collins gets around 5.3 in of rain over 23 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 4 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 42 min in early June to 13 hours by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 7.0 kWh/m².
Is summer a good time to visit Fort Collins?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Fort Collins for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Fort Collins in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Fort Collins sees daytime highs around 83°F and nights near 56°F. Pack light clothes and sun protection. Worth having: rain gear. About 23 days see rain.
UV index in Fort Collins in Summer
Clear-sky midday UV across summer averages around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Fort Collins peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 6 | 6 | 8 | 10 | 11 | 10 | 7 | 5 | 3 | 2 |
| Level | Low | Moderate | High | High | Very high | Extreme | Extreme | Very high | Very high | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 4 | Moderate |
| Mar | 6 | High |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 10 | Extreme |
| Jul | 11 | Extreme |
| Aug | 10 | Very high |
| Sep | 7 | Very high |
| Oct | 5 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Fort Collins in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Fort Collins 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 Fort Collins?
Fort Collins sits at 40.6°N, 105.1°W, 5,003 ft above sea level, in United States. The nearest listed city is Windsor, 12 mi away.
Topography around Fort Collins
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Fort Collins.
Within 2 miles, the terrain around Fort Collins has only modest variations in elevation — a maximum elevation change of 187 ft around an average of 5,003 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,923 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,675 ft.
The land around Fort Collins is covered by artificial surfaces (41%), trees (32%) and grassland (22%) within 2 miles, grassland (57%) within 10 miles, and grassland (57%) and trees (24%) 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 Fort Collins (40.5853°, -105.0844°, elevation 5,003 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.