Brighton weather in December

In December, Brighton sees average daytime highs of 42°F and overnight lows near 20°F, with 0.5 in of precipitation across 3 wet days and about 9.2 hours of daylight. It is the 11th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 45°F in the first days to 40°F by the end. The sky is clear or mostly clear about 52% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of December to 9 h 12 min by month's end. Set against the rest of the year, December is Brighton's 4th-clearest and 7th-windiest month. For the whole year in context, see Brighton's year-round climate.

Daytime high
42°
11th warmest
Overnight low
20°
2nd coldest
Precipitation
0.5 in
3 wet days
Daylight
9 h 12 min
7:20 AM – 4:31 PM
Cloud cover
41%
4th clearest
Wind
5 mph
7th windiest
Solar energy
2.42 kWh/m²
Travel score
0.5
out of 10

Brighton is city in and county seat of Adams County, Colorado, United States.

Density
716/km²
people per km²
Founded
1887

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 45°F in the first days to 40°F by the end.

A typical December day in Brighton reaches about 42°F in the afternoon and slips back to 20°F overnight — a 23°F spread between the day's warmth and the night's chill. On most days the high lands between 27°F and 58°F. Set against its neighbours, December runs about 10°F cooler than November and on par with January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14622
24622
34522
44522
54521
64421
74421
84421
94420
104420
114320
124320
134320
144320
154220
164219
174219
184219
194219
204119
214119
224119
234118
244118
254118
264118
274018
284018
294018
304018
314018

How December really feels in Brighton

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
26 feel bitter (≤ 14°F)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Brighton weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan42° / 19°0.53.33.59.50.4
Feb46° / 22°0.53.63.510.41.5
Mar56° / 29°1.35.43.411.74.3
Apr63° / 37°2.07.63.2135.8
May72° / 46°2.59.50.614.26.7
Jun83° / 55°1.57014.86.3
Jul89° / 61°1.36.9014.54.6
Aug87° / 60°1.25.7013.65.5
Sep79° / 51°1.04.20.412.37.7
Oct65° / 38°1.25.11.510.96.9
Nov52° / 27°0.74.13.39.83.4
Dec42° / 20°0.533.29.20.5

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 32%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16931
26931
36931
46931
56931
66931
76931
86931
96931
106931
116832
126832
136832
146832
156832
166832
176832
186832
196931
206931
216931
226832
236832
246832
256832
266832
276832
286733
296733
306832
316733

Chance of precipitation in December

Any precipitationSnow

Brighton gets around 0.5 in of rain and snow over 3 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 10% and peaks near 12% on the wettest days, and about 3 days bring snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
11211
21111
31111
41111
51010
61010
71010
81010
91010
101010
111010
121010
131011
141111
151111
161111
171111
181112
191112
201112
211112
221012
231012
241011
251011
261011
271011
281011
291011
301011
31911

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 5 mph in December.

Across December, 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.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 24 min at the start of December to 9 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:08 AM to 7:27 AM, and sunset from 4:30 PM to 4:38 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:084:30
29.47:094:30
39.37:104:30
49.37:114:30
59.37:124:30
69.37:134:29
79.37:134:29
89.37:144:29
99.27:154:29
109.27:164:30
119.27:174:30
129.27:174:30
139.27:184:30
149.27:194:30
159.27:204:30
169.27:204:31
179.27:214:31
189.27:214:31
199.27:224:32
209.27:234:32
219.27:234:33
229.27:244:33
239.27:244:33
249.27:244:34
259.27:254:35
269.27:254:35
279.27:264:36
289.27:264:36
299.27:264:37
309.27:264:38
319.27:274:38

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.42 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.42 kWh/m² to a high of 7.39 kWh/m² in June across the year — December's 2.42 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.5Moderate
22.5Moderate
32.5Moderate
42.5Moderate
52.5Moderate
62.4Moderate
72.4Moderate
82.4Moderate
92.4Moderate
102.4Moderate
112.4Moderate
122.4Moderate
132.4Moderate
142.4Moderate
152.4Moderate
162.4Moderate
172.4Moderate
182.4Moderate
192.4Moderate
202.4Moderate
212.4Moderate
222.4Moderate
232.4Moderate
242.4Moderate
252.4Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.5Moderate
Planning a trip in December

Is December a good time to visit Brighton?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.5
Sightseeing
11th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Brighton.

What to pack for Brighton in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Brighton sees daytime highs around 42°F and nights near 20°F. Pack a warm layer and a heavy coat. About 3 days see rain.

a warm layera heavy coat

UV index in Brighton in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Brighton peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 12UV 11Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb4Moderate
Mar7High
Apr6High
May7Very high
Jun10Extreme
Jul11Extreme
Aug10Very high
Sep7Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Brighton in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Brighton 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).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateAug 1620 µg/m³May 1113 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb15Moderate
Mar16Moderate
Apr13Moderate
May13Moderate
Jun14Moderate
Jul14Moderate
Aug21Moderate
Sep13Moderate
Oct15Moderate
Nov15Moderate
Dec16Moderate
Location & terrain

Where is Brighton?

Brighton sits at 40.0°N, 104.8°W, 4,984 ft above sea level, in United States. The nearest listed city is Northglenn, 11 mi away.

Topography around Brighton

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Brighton.

Within 2 miles, the terrain around Brighton has only modest variations in elevation — a maximum elevation change of 194 ft around an average of 4,990 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 640 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 9,626 ft.

The land around Brighton is covered by artificial surfaces (34%), grassland (32%) and cropland (21%) within 2 miles, grassland (51%) and cropland (28%) within 10 miles, and grassland (48%), trees (22%) and cropland (20%) within 50 miles.

2 miles
194 ft
10 miles
640 ft
50 miles
9,626 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Northglenn 11 mi · Thornton 11 mi · Erie 13 mi · Commerce City 14 mi · Sherrelwood 14 mi · Lafayette 14 mi · Broomfield 15 mi · Westminster 16 mi

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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 Brighton (39.9853°, -104.8205°, 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. 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).