Adelanto weather in December

In December, Adelanto sees average daytime highs of 54°F and overnight lows near 38°F, with 1.5 in of precipitation across 4.3 wet days and about 9.7 hours of daylight. It is the 12th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 57°F in the first days to 53°F by the end. The sky is clear or mostly clear about 53% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 54 min at the start of December to 9 h 42 min by month's end. Set against the rest of the year, December is Adelanto's 9th-clearest and 9th-windiest month. For the whole year in context, see Adelanto's year-round climate.

Daytime high
54°
12th warmest
Overnight low
38°
1st coldest
Precipitation
1.5 in
4.3 wet days
Daylight
9 h 42 min
6:55 AM – 4:37 PM
Cloud cover
41%
9th clearest
Wind
5 mph
9th windiest
Solar energy
3.07 kWh/m²
Travel score
4.0
out of 10

Adelanto is city in San Bernardino County, California, United States.

Density
229/km²
people per km²
Founded
1915

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 57°F in the first days to 53°F by the end.

A typical December day in Adelanto reaches about 54°F in the afternoon and slips back to 38°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 45°F and 64°F. Set against its neighbours, December runs about 9°F cooler than November and on par with January.

20°30°40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15740
25740
35740
45640
55639
65639
75639
85539
95539
105538
115538
125538
135538
145438
155438
165438
175438
185437
195437
205337
215337
225337
235337
245337
255337
265337
275337
285337
295337
305337
315337

How December really feels in Adelanto

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 0 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
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Adelanto weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan55° / 39°1.95.31.59.94.1
Feb57° / 40°2.361.910.74.6
Mar62° / 43°1.45.51.111.76.3
Apr69° / 47°0.73.40.612.87.8
May77° / 53°0.32.1013.88.7
Jun86° / 60°0.10.8014.36.8
Jul92° / 66°0.43.1014.14.4
Aug92° / 67°0.32.6013.34.5
Sep85° / 62°0.31.6012.26.8
Oct75° / 54°0.41.8011.18.8
Nov63° / 44°0.62.70.410.26.9
Dec54° / 38°1.54.319.74.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 53% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 34%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17030
27030
36931
46733
56733
66733
76634
86634
96634
106733
116634
126634
136634
146634
156634
166733
176733
186733
196733
206733
216733
226634
236535
246535
256436
266436
276238
286238
296139
306139
316139

Chance of precipitation in December

Any precipitationSnow

Adelanto gets around 1.5 in of rain and snow over 4.3 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 14% and peaks near 15% on the wettest days, and about 1 day brings snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
1132
2132
3132
4142
5142
6142
7142
8142
9142
10142
11142
12142
13142
14142
15142
16143
17143
18143
19143
20143
21144
22144
23144
24144
25144
26145
27145
28145
29155
30155
31155

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 54 min at the start of December to 9 h 42 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 6:44 AM to 7:01 AM, and sunset from 4:35 PM to 4:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.96:444:35
29.86:454:35
39.86:464:35
49.86:464:35
59.86:474:35
69.86:484:35
79.86:494:35
89.86:494:35
99.76:504:35
109.76:514:35
119.76:524:35
129.76:524:36
139.76:534:36
149.76:544:36
159.76:544:36
169.76:554:37
179.76:564:37
189.76:564:37
199.76:574:38
209.76:574:38
219.76:584:39
229.76:584:39
239.76:594:40
249.76:594:40
259.76:594:41
269.77:004:41
279.77:004:42
289.77:014:42
299.77:014:43
309.77:014:44
319.77:014:44

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.07 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.07 kWh/m² to a high of 8.49 kWh/m² in June across the year — December's 3.07 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.2Moderate
23.2Moderate
33.1Moderate
43.1Moderate
53.1Moderate
63.1Moderate
73.1Moderate
83.0Moderate
93.0Moderate
103.0Moderate
113.0Moderate
123.0Moderate
133.0Moderate
143.0Moderate
153.0Moderate
163.0Moderate
173.0Moderate
183.0Moderate
193.0Moderate
203.0Moderate
213.0Moderate
223.0Moderate
233.0Moderate
243.0Moderate
253.0Moderate
263.1Moderate
273.1Moderate
283.1Moderate
293.1Moderate
303.1Moderate
313.1Moderate
Planning a trip in December

Is December a good time to visit Adelanto?

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

4.0
Sightseeing
12th-best month of the year
0.0
Beach & pool
11th-best month of the year

December is a reasonable time to visit Adelanto for sightseeing.

What to pack for Adelanto in December

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

In December, Adelanto sees daytime highs around 54°F and nights near 38°F. Worth packing: a warm layer. About 4 days see rain.

a warm layer

UV index in Adelanto in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Adelanto peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 11Dec 15UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5High
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Adelanto 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 Adelanto is worst in September — around 39 µg/m³ PM2.5 (poor), about 3.2× the cleanest month (May, 12 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateModerateSep 1537 µg/m³May 1612 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb15Moderate
Mar16Moderate
Apr14Moderate
May12Moderate
Jun15Moderate
Jul18Moderate
Aug22Moderate
Sep39Poor
Oct15Moderate
Nov17Moderate
Dec14Moderate
Location & terrain

Where is Adelanto?

Adelanto sits at 34.6°N, 117.4°W, 2,871 ft above sea level, in United States. The nearest listed city is Victorville, 7.5 mi away.

Topography around Adelanto

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

Within 2 miles, the terrain around Adelanto has only modest variations in elevation — a maximum elevation change of 157 ft around an average of 2,874 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,008 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 11,230 ft.

The land around Adelanto is covered by grassland (39%) and bare terrain (39%) within 2 miles, bare terrain (47%) and grassland (28%) within 10 miles, and bare terrain (39%), grassland (21%) and shrubs (20%) within 50 miles.

2 miles
157 ft
10 miles
2,008 ft
50 miles
11,230 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrain
December weather nearby: Victorville 7.5 mi · Hesperia 12 mi · Apple Valley 14 mi · Barstow Heights 28 mi · Barstow 31 mi · Rialto 33 mi · Highland 34 mi · San Bernardino 34 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 Adelanto (34.5828°, -117.4092°, elevation 2,871 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).