Boulder weather in April
In April, Boulder sees average daytime highs of 54°F and overnight lows near 29°F, with 3.1 in of precipitation across 11.1 wet days and about 13 hours of daylight. It is the 7th-warmest and 2nd-wettest month of the year here.
Highs climb over the month, from about 51°F in the first days to 56°F by the end. The sky is clear or mostly clear about 27% of the time in April, and the air most often feels dry.
Daylight stretches from about 12 h 24 min at the start of April to 13 h 36 min by month's end. Set against the rest of the year, April is Boulder's 11th-clearest and 4th-windiest month. For the whole year in context, see Boulder's year-round climate.
- Daytime high
- 54°
- 7th warmest
- Overnight low
- 29°
- 6th coldest
- Precipitation
- 3.1 in
- 11.1 wet days
- Daylight
- 13 h 06 min
- 5:30 AM – 6:33 PM
- Cloud cover
- 60%
- 11th clearest
- Wind
- 5 mph
- 4th windiest
- Solar energy
- 6.37 kWh/m²
- Travel score
- 3.1
- out of 10
Boulder is city in and county seat of Boulder County, Colorado, United States.
- Density
- 1,606/km²
- people per km²
- Founded
- 1858
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in April
Highs climb over the month, from about 51°F in the first days to 56°F by the end.
A typical April day in Boulder reaches about 54°F in the afternoon and slips back to 29°F overnight — a 25°F spread between the day's warmth and the night's chill. On most days the high lands between 39°F and 67°F. Set against its neighbours, April runs about 6°F warmer than March and about 9°F cooler than May.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 51 | 51 | 51 | 52 | 52 | 52 | 52 | 52 | 53 | 53 | 53 | 53 | 53 | 53 | 54 | 54 | 54 | 54 | 54 | 54 | 55 | 55 | 55 | 55 | 55 | 56 | 56 | 56 | 56 | 57 |
| Avg low (°F) | 26 | 26 | 26 | 26 | 27 | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 28 | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 31 | 31 | 31 | 31 | 31 | 32 | 32 | 32 | 33 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 51 | 26 |
| 2 | 51 | 26 |
| 3 | 51 | 26 |
| 4 | 52 | 26 |
| 5 | 52 | 27 |
| 6 | 52 | 27 |
| 7 | 52 | 27 |
| 8 | 52 | 27 |
| 9 | 53 | 28 |
| 10 | 53 | 28 |
| 11 | 53 | 28 |
| 12 | 53 | 28 |
| 13 | 53 | 28 |
| 14 | 53 | 29 |
| 15 | 54 | 29 |
| 16 | 54 | 29 |
| 17 | 54 | 29 |
| 18 | 54 | 29 |
| 19 | 54 | 30 |
| 20 | 54 | 30 |
| 21 | 55 | 30 |
| 22 | 55 | 31 |
| 23 | 55 | 31 |
| 24 | 55 | 31 |
| 25 | 55 | 31 |
| 26 | 56 | 31 |
| 27 | 56 | 32 |
| 28 | 56 | 32 |
| 29 | 56 | 32 |
| 30 | 57 | 33 |
How April really feels in Boulder
Once humidity and wind are folded in, April averages 0 days that feel above 90°F and 30 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
The story in April is cold — wind chill drags the overnight "feels like" below the raw low.
Boulder weather by month
How April compares with the rest of the year at a glance. April is the 7th-warmest and 2nd-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 37° / 14° | 0.9 | 5.7 | 5.5 | 9.5 | 0.0 |
| Feb | 39° / 16° | 1.0 | 6.7 | 7 | 10.4 | 0.0 |
| Mar | 48° / 22° | 2.0 | 8.8 | 7.2 | 11.7 | 1.7 |
| Apr | 54° / 29° | 3.1 | 11.1 | 7.9 | 13 | 3.1 |
| May | 63° / 38° | 4.0 | 14.9 | 3.5 | 14.2 | 4.8 |
| Jun | 74° / 47° | 3.0 | 14.3 | 0.3 | 14.8 | 6.2 |
| Jul | 80° / 53° | 3.0 | 14.8 | 0 | 14.5 | 6.0 |
| Aug | 78° / 52° | 2.8 | 14.9 | 0 | 13.6 | 6.2 |
| Sep | 71° / 44° | 2.1 | 9.7 | 0.9 | 12.3 | 6.8 |
| Oct | 58° / 33° | 1.9 | 7.4 | 3.9 | 10.9 | 4.9 |
| Nov | 46° / 22° | 1.3 | 6.4 | 5.7 | 9.8 | 1.4 |
| Dec | 37° / 15° | 0.9 | 5.3 | 5.4 | 9.2 | 0.0 |
Cloud cover in April
The sky is clear or mostly clear about 27% of the time in April.
Beyond those clear spells, partly cloudy skies cover about 20% of April, with mostly cloudy or overcast conditions the remaining 53%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 50 | 49 | 49 | 49 | 49 | 50 | 50 | 48 | 48 | 48 | 47 | 46 | 46 | 47 | 46 | 46 | 45 | 46 | 46 | 46 | 46 | 46 | 46 | 46 | 46 | 47 | 46 | 47 | 47 | 47 |
| Cloudier (%) | 50 | 51 | 51 | 51 | 51 | 50 | 50 | 52 | 52 | 52 | 53 | 54 | 54 | 53 | 54 | 54 | 55 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 54 | 53 | 54 | 53 | 53 | 53 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 50 | 50 |
| 2 | 49 | 51 |
| 3 | 49 | 51 |
| 4 | 49 | 51 |
| 5 | 49 | 51 |
| 6 | 50 | 50 |
| 7 | 50 | 50 |
| 8 | 48 | 52 |
| 9 | 48 | 52 |
| 10 | 48 | 52 |
| 11 | 47 | 53 |
| 12 | 46 | 54 |
| 13 | 46 | 54 |
| 14 | 47 | 53 |
| 15 | 46 | 54 |
| 16 | 46 | 54 |
| 17 | 45 | 55 |
| 18 | 46 | 54 |
| 19 | 46 | 54 |
| 20 | 46 | 54 |
| 21 | 46 | 54 |
| 22 | 46 | 54 |
| 23 | 46 | 54 |
| 24 | 46 | 54 |
| 25 | 46 | 54 |
| 26 | 47 | 53 |
| 27 | 46 | 54 |
| 28 | 47 | 53 |
| 29 | 47 | 53 |
| 30 | 47 | 53 |
Chance of precipitation in April
Boulder gets around 3.1 in of rain and snow over 11.1 wet days in April. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable precipitation averages around 37% and peaks near 43% on the wettest days, and about 8 days bring snow. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 35 | 35 | 34 | 34 | 34 | 33 | 33 | 32 | 32 | 32 | 33 | 33 | 33 | 34 | 35 | 36 | 37 | 38 | 38 | 39 | 40 | 41 | 41 | 42 | 42 | 43 | 43 | 43 | 43 | 43 |
| Snow chance (%) | 27 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 24 | 23 | 22 |
| Rain chance (%) | Snow chance (%) | |
|---|---|---|
| 1 | 35 | 27 |
| 2 | 35 | 27 |
| 3 | 34 | 27 |
| 4 | 34 | 27 |
| 5 | 34 | 26 |
| 6 | 33 | 26 |
| 7 | 33 | 26 |
| 8 | 32 | 25 |
| 9 | 32 | 25 |
| 10 | 32 | 25 |
| 11 | 33 | 25 |
| 12 | 33 | 25 |
| 13 | 33 | 25 |
| 14 | 34 | 25 |
| 15 | 35 | 25 |
| 16 | 36 | 25 |
| 17 | 37 | 26 |
| 18 | 38 | 26 |
| 19 | 38 | 26 |
| 20 | 39 | 26 |
| 21 | 40 | 26 |
| 22 | 41 | 26 |
| 23 | 41 | 26 |
| 24 | 42 | 26 |
| 25 | 42 | 26 |
| 26 | 43 | 25 |
| 27 | 43 | 25 |
| 28 | 43 | 24 |
| 29 | 43 | 23 |
| 30 | 43 | 22 |
Humidity in April
Most of April feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, April lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Dry (%) | |
|---|---|
| 1 | 100 |
| 2 | 100 |
| 3 | 100 |
| 4 | 100 |
| 5 | 100 |
| 6 | 100 |
| 7 | 100 |
| 8 | 100 |
| 9 | 100 |
| 10 | 100 |
| 11 | 100 |
| 12 | 100 |
| 13 | 100 |
| 14 | 100 |
| 15 | 100 |
| 16 | 100 |
| 17 | 100 |
| 18 | 100 |
| 19 | 100 |
| 20 | 100 |
| 21 | 100 |
| 22 | 100 |
| 23 | 100 |
| 24 | 100 |
| 25 | 100 |
| 26 | 100 |
| 27 | 100 |
| 28 | 100 |
| 29 | 100 |
| 30 | 100 |
Wind in April
Winds average 5 mph in April.
Across April, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 5 | calm |
| 2 | 5 | calm |
| 3 | 5 | calm |
| 4 | 5 | calm |
| 5 | 5 | calm |
| 6 | 5 | calm |
| 7 | 5 | calm |
| 8 | 5 | calm |
| 9 | 5 | calm |
| 10 | 5 | calm |
| 11 | 5 | calm |
| 12 | 5 | calm |
| 13 | 5 | calm |
| 14 | 5 | calm |
| 15 | 5 | calm |
| 16 | 5 | calm |
| 17 | 5 | calm |
| 18 | 5 | calm |
| 19 | 5 | calm |
| 20 | 5 | calm |
| 21 | 5 | calm |
| 22 | 5 | calm |
| 23 | 5 | calm |
| 24 | 5 | calm |
| 25 | 5 | calm |
| 26 | 5 | calm |
| 27 | 5 | calm |
| 28 | 5 | calm |
| 29 | 5 | calm |
| 30 | 5 | calm |
Sunrise & sunset in April
Daylight runs from about 12 h 24 min at the start of April to 13 h 36 min by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 72 minutes over April. Sunrise moves from 5:54 AM to 5:09 AM, and sunset from 6:18 PM to 6:47 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.4 | 12.4 | 12.5 | 12.5 | 12.6 | 12.6 | 12.7 | 12.7 | 12.8 | 12.8 | 12.8 | 12.9 | 12.9 | 13.0 | 13.0 | 13.1 | 13.1 | 13.1 | 13.2 | 13.2 | 13.3 | 13.3 | 13.4 | 13.4 | 13.4 | 13.5 | 13.5 | 13.6 | 13.6 | 13.6 |
| Sunrise (AM) | 5:54 | 5:52 | 5:51 | 5:49 | 5:47 | 5:46 | 5:44 | 5:42 | 5:41 | 5:39 | 5:38 | 5:36 | 5:34 | 5:33 | 5:31 | 5:30 | 5:28 | 5:27 | 5:25 | 5:24 | 5:22 | 5:21 | 5:19 | 5:18 | 5:16 | 5:15 | 5:13 | 5:12 | 5:11 | 5:09 |
| Sunset (PM) | 6:18 | 6:19 | 6:20 | 6:21 | 6:22 | 6:23 | 6:24 | 6:25 | 6:26 | 6:27 | 6:28 | 6:29 | 6:30 | 6:31 | 6:32 | 6:33 | 6:34 | 6:35 | 6:36 | 6:37 | 6:38 | 6:39 | 6:40 | 6:41 | 6:42 | 6:43 | 6:44 | 6:45 | 6:46 | 6:47 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.4 | 5:54 | 6:18 |
| 2 | 12.4 | 5:52 | 6:19 |
| 3 | 12.5 | 5:51 | 6:20 |
| 4 | 12.5 | 5:49 | 6:21 |
| 5 | 12.6 | 5:47 | 6:22 |
| 6 | 12.6 | 5:46 | 6:23 |
| 7 | 12.7 | 5:44 | 6:24 |
| 8 | 12.7 | 5:42 | 6:25 |
| 9 | 12.8 | 5:41 | 6:26 |
| 10 | 12.8 | 5:39 | 6:27 |
| 11 | 12.8 | 5:38 | 6:28 |
| 12 | 12.9 | 5:36 | 6:29 |
| 13 | 12.9 | 5:34 | 6:30 |
| 14 | 13.0 | 5:33 | 6:31 |
| 15 | 13.0 | 5:31 | 6:32 |
| 16 | 13.1 | 5:30 | 6:33 |
| 17 | 13.1 | 5:28 | 6:34 |
| 18 | 13.1 | 5:27 | 6:35 |
| 19 | 13.2 | 5:25 | 6:36 |
| 20 | 13.2 | 5:24 | 6:37 |
| 21 | 13.3 | 5:22 | 6:38 |
| 22 | 13.3 | 5:21 | 6:39 |
| 23 | 13.4 | 5:19 | 6:40 |
| 24 | 13.4 | 5:18 | 6:41 |
| 25 | 13.4 | 5:16 | 6:42 |
| 26 | 13.5 | 5:15 | 6:43 |
| 27 | 13.5 | 5:13 | 6:44 |
| 28 | 13.6 | 5:12 | 6:45 |
| 29 | 13.6 | 5:11 | 6:46 |
| 30 | 13.6 | 5:09 | 6:47 |
Solar energy in April
Average shortwave solar energy reaching the ground each day in April, about 6.37 kWh/m².
For context, solar energy here swings from a low near 2.56 kWh/m² to a high of 7.49 kWh/m² in June across the year — April's 6.37 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.0 | 6.0 | 6.0 | 6.1 | 6.1 | 6.1 | 6.2 | 6.2 | 6.2 | 6.3 | 6.3 | 6.3 | 6.3 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.6 | 6.6 | 6.6 | 6.6 | 6.7 | 6.7 |
| Level | Bright | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.0 | Bright |
| 2 | 6.0 | Bright |
| 3 | 6.0 | Intense |
| 4 | 6.1 | Intense |
| 5 | 6.1 | Intense |
| 6 | 6.1 | Intense |
| 7 | 6.2 | Intense |
| 8 | 6.2 | Intense |
| 9 | 6.2 | Intense |
| 10 | 6.3 | Intense |
| 11 | 6.3 | Intense |
| 12 | 6.3 | Intense |
| 13 | 6.3 | Intense |
| 14 | 6.4 | Intense |
| 15 | 6.4 | Intense |
| 16 | 6.4 | Intense |
| 17 | 6.4 | Intense |
| 18 | 6.4 | Intense |
| 19 | 6.5 | Intense |
| 20 | 6.5 | Intense |
| 21 | 6.5 | Intense |
| 22 | 6.5 | Intense |
| 23 | 6.5 | Intense |
| 24 | 6.5 | Intense |
| 25 | 6.6 | Intense |
| 26 | 6.6 | Intense |
| 27 | 6.6 | Intense |
| 28 | 6.6 | Intense |
| 29 | 6.7 | Intense |
| 30 | 6.7 | Intense |
Hazard calendar for Boulder
In April, Boulder sits inside its rainy season season. The full year is below, with each hazard's peak months called out.
Boulder's rainy season runs March–October, when most of the year's rain falls.
Is April a good time to visit Boulder?
Our two travel scores rate April for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
April is a weaker month for outdoor sightseeing in Boulder.
What to pack for Boulder in April
From April's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In April, Boulder sees daytime highs around 54°F and nights near 29°F. Pack sun protection. Worth having: a warm layer and rain gear. About 11 days see rain.
UV index in Boulder in April
Clear-sky midday UV in April peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Boulder 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 Boulder in April
Average fine-particle pollution (PM2.5) through the year — so you can see where April falls, not just the annual average.
Air quality in Boulder is worst in August — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (May, 13 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) | 17 | 15 | 16 | 13 | 13 | 14 | 14 | 21 | 13 | 15 | 15 | 16 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 17 | Moderate |
| Feb | 15 | Moderate |
| Mar | 16 | Moderate |
| Apr | 13 | Moderate |
| May | 13 | Moderate |
| Jun | 14 | Moderate |
| Jul | 14 | Moderate |
| Aug | 21 | Moderate |
| Sep | 13 | Moderate |
| Oct | 15 | Moderate |
| Nov | 15 | Moderate |
| Dec | 16 | Moderate |
Where is Boulder?
Boulder sits at 40.0°N, 105.3°W, 5,328 ft above sea level, in United States. The nearest listed city is Louisville, 8.1 mi away.
Topography around Boulder
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Boulder.
Within 2 miles, the terrain around Boulder has significant variations in elevation — a maximum elevation change of 1,703 ft around an average of 5,495 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 4,147 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,623 ft.
The land around Boulder is covered by trees (45%) and artificial surfaces (39%) within 2 miles, grassland (44%) and trees (41%) within 10 miles, and trees (41%) and grassland (34%) 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 Boulder (40.015°, -105.2706°, elevation 5,328 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).