Boulder, UT Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Boulder's primary NOAA station, BOULDER.
The climate verdict for Boulder
Dryness leads the climate profile for Boulder, Utah, with 11.8 inches of precipitation a year. NOAA records an annual average of 50°F. At 44/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 10% of scores.
- 50°F
- yearly average temperature, NOAA normal
- 44/100
- comfort score, above 10% of station-mapped location scores
- 11.8"
- annual precipitation · 52" snow
- 163 days
- frost-free growing season
Boulder: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00420849 · Boulder, UT 50°F mean · 11.8" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-ARID · SWING-MID · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 50°F
- RANK-MID #2,813
- PHOTO-FINISH ≈ Wheat Ridge
- PRCP-ARID 11.8"
- SWING-MID 42°F
- COMF-LOW 44/100
- LOAD-HEAT 5,906 HDD
- STN-1 USC00420849
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Wheat Ridge, CO (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every UT station list.
- Boulder (this station) 50°F
- Cold Westhamptn Gabr…, NY 50°F
- Hot Mtn Dell Dam, UT 50°F
- Near Wheat Ridge, CO 50°F
- Near Riggins, ID 50°F
Climate Living Index · Boulder
Boulder: 39/100 · grade F
Boulder publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Boulder, not an official NOAA rating. Rankings still use Comfort Score 44/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 134 calendar days | 56/100 · C |
| Annual temperature balance | 50.3°F · 17.2° from 67.5°F | 42/100 · D |
| Frost-free season | 163 days/year | 36/100 · F |
| Snowfall burden | 51.6 inches/year | 20/100 · F |
| Precipitation balance | 11.8 in · 23.1 from 35 in | 18/100 · F |
Boulder · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Boulder's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 72.4°F
- Coldest month
- 30.2°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Boulder sits across the climate record
Three NOAA fields for Boulder's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 41st percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Drier than 90%
- Boulder's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 45th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Boulder compares across U.S. station-mapped locations
Boulder's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
44 10th percentile score exceeds 10% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Boulder's measured station temperature trend
MethodologyAcross 61 complete annual observations from 1955 to 2025, BOULDER warmed at a fitted rate of 0.24°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Boulder primary station fitted change +0.24 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 40°F (4°C) | 21°F (-6°C) | 30°F (-1°C) | 1.1" | 15.7" | 30.3 | 0.0 |
| February | 44°F (6°C) | 25°F (-4°C) | 34°F (1°C) | 1.1" | 10.8" | 25.3 | 0.0 |
| March | 53°F (12°C) | 31°F (-1°C) | 42°F (5°C) | 0.9" | 6.7" | 19.7 | 0.0 |
| April | 60°F (15°C) | 36°F (2°C) | 48°F (9°C) | 0.5" | 2.3" | 11.6 | 0.0 |
| May | 68°F (20°C) | 45°F (7°C) | 56°F (14°C) | 0.7" | 0.4" | 2.8 | 0.0 |
| June | 79°F (26°C) | 54°F (12°C) | 67°F (19°C) | 0.4" | 0.0" | 0.1 | 1.3 |
| July | 84°F (29°C) | 61°F (16°C) | 72°F (22°C) | 1.1" | 0.0" | 0.0 | 4.7 |
| August | 81°F (27°C) | 60°F (15°C) | 70°F (21°C) | 1.7" | 0.0" | 0.0 | 1.9 |
| September | 74°F (23°C) | 52°F (11°C) | 63°F (17°C) | 1.6" | 0.0" | 0.3 | 0.1 |
| October | 62°F (17°C) | 41°F (5°C) | 52°F (11°C) | 1.4" | 0.5" | 6.1 | 0.0 |
| November | 49°F (10°C) | 30°F (-1°C) | 40°F (4°C) | 0.6" | 3.5" | 20.1 | 0.0 |
| December | 39°F (4°C) | 21°F (-6°C) | 30°F (-1°C) | 0.8" | 11.7" | 29.6 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 84°F around July 17, short of 90°F on every date, while 134 dates carry a normal low at or below freezing, the coldest 20°F near December 22.
The freezing stretch
The normal low stays at or below 32°F into March 22, then returns to freezing around November 10, covering 134 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is August 5, when 32% of years recorded at least a hundredth of an inch. The driest is June 12 at 12%. Summed across the calendar, that is about 67 wet dates a year.
The widest day
June 8 carries the biggest normal gap between afternoon and dawn, 25°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Boulder.
Where Boulder Stands Nationally
A drier-than-most normal water year — around 12 inches, below what four out of five ranked stations collect.
Boulder earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 15.7"
5.5 days with precipitation
Snow: 10.8"
6.1 days with precipitation
Snow: 6.7"
4.6 days with precipitation
Snow: 2.3"
4.3 days with precipitation
Snow: 0.4"
5.4 days with precipitation
2.8 days with precipitation
8.1 days with precipitation
9.8 days with precipitation
6.9 days with precipitation
Snow: 0.5"
5.2 days with precipitation
Snow: 3.5"
3.1 days with precipitation
Snow: 11.7"
5.2 days with precipitation
Boulder spreads its precipitation across the year
Neither half of the year dominates here: June through August take 27% of the annual total and December through February 25%, with neither reaching the 35% that would mark a distinct wet season. Boulder has no dry season to plan around, though it does carry a 42.2°F seasonal spread.
The gap between the wettest and driest month still matters: August averages 1.7" and June 0.4". The three wettest months together take 40% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
Boulder is dry, and what does fall arrives gently
Only about 67 days a year record measurable precipitation here, 18% of the calendar, and they carry 11.9" between them. At roughly 0.18 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is August at about 10 wet days; the driest is June at about 3.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Winter brings real snow to Boulder
Boulder averages 51.6 inches of snowfall a year, with January the snowiest month on the normals, spread across roughly 16 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 51.6 inches of depth.
- Days recording measurable snow: about 16 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 44% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 14
50% probability date
Last Spring Freeze
May 4
50% probability date
Growing Season
163 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,906
Higher = more heating needed
Cooling Degree Days
580
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside UT closest to Boulder on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (50°F here).
- Bedford, IA 50°F · 0.0°F off
- Central City, NE 50°F · 0.0°F off
- Chatham, MA 50°F · 0.0°F off
- Clarinda, IA 50°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (11.8" here), excluding temperature-peer places.
- Fullerton, CA 11.9" · 0.0" off
- Oceanside, CA 11.9" · 0.0" off
- Fresno, CA 11.8" · 0.0" off
- King City, CA 11.8" · 0.0" off
Snow and freeze rhythm
When cold and snow define Boulder
heating led · dry · mid swing
Boulder's energy balance leans toward cold weather: 5,906 annual heating degree days against 580 for cooling. Its 42.2°F seasonal range still makes the monthly rows more useful than the annual average alone.
Boulder's frost-free season lasts about 163 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Boulder coldest normal
December
The monthly mean of 30°F (-1°C) sits near freezing, so cold nights and above-freezing afternoons share the same month.
-
2. Boulder typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Boulder snow peak
January
Boulder averages 51.6 inches of snow a year, with January the snowiest month on the normals.
Questions about Boulder's climate
How much snow does Boulder get? ▼
How cold does Boulder get in winter? ▼
How much energy does heating and cooling require in Boulder? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Boulder's primary station: BOULDER (USC00420849). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 4907470). Match rule for Boulder: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Boulder comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.