Fontana weather in December

In December, Fontana sees average daytime highs of 62°F and overnight lows near 42°F, with 2.6 in of precipitation across 5.8 wet days and about 9.8 hours of daylight. It is the 12th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 65°F in the first days to 62°F by the end. The sky is clear or mostly clear about 51% 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 48 min by month's end. Set against the rest of the year, December is Fontana's 9th-clearest and 4th-windiest month. For the whole year in context, see Fontana's year-round climate.

Daytime high
62°
12th warmest
Overnight low
42°
1st coldest
Precipitation
2.6 in
5.8 wet days
Daylight
9 h 42 min
6:54 AM – 4:38 PM
Cloud cover
43%
9th clearest
Wind
3 mph
4th windiest
Solar energy
2.98 kWh/m²
Travel score
6.2
out of 10

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

Density
1,935/km²
people per km²
Founded
1913

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 65°F in the first days to 62°F by the end.

A typical December day in Fontana reaches about 62°F in the afternoon and slips back to 42°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 53°F and 72°F. Set against its neighbours, December runs about 7°F cooler than November and on par with January.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16544
26544
36444
46444
56444
66443
76443
86343
96343
106343
116343
126342
136242
146242
156242
166242
176242
186242
196242
206241
216241
226241
236141
246141
256141
266141
276141
286241
296241
306241
316241

How December really feels in Fontana

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.

Fontana weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan63° / 42°3.86.6106.2
Feb64° / 44°4.47.410.76.2
Mar67° / 47°2.76.811.76.8
Apr71° / 50°1.24.612.87.8
May76° / 55°0.62.613.78.6
Jun83° / 60°0.10.514.27.8
Jul89° / 65°0.10.5145.5
Aug91° / 67°0.00.313.34.9
Sep88° / 63°0.21.212.26.1
Oct79° / 56°0.93.111.18.3
Nov70° / 48°1.23.510.27.9
Dec62° / 42°2.65.89.86.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 51% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 37%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16832
26733
36634
46634
56535
66535
76436
86436
96337
106337
116337
126337
136337
146337
156337
166337
176337
186337
196337
206436
216436
226337
236337
246337
256238
266238
276139
286139
296040
305941
315941

Chance of precipitation in December

Any precipitation

Fontana gets around 2.6 in of rain and snow over 5.8 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 19% and peaks near 20% on the wettest days, and about 0 day brings snow.

0%10%20%30%151015202531
Rain chance (%)
117
217
318
418
519
619
719
819
919
1019
1120
1219
1319
1419
1519
1619
1719
1819
1919
2019
2119
2219
2319
2419
2519
2619
2719
2819
2919
3020
3120

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 (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 3 mph in December.

Across December, daily wind ranges from about 3 mph on the calmest days to 3 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
13calm
23calm
33calm
43calm
53calm
63calm
73calm
83calm
93calm
103calm
113calm
123calm
133calm
143calm
153calm
163calm
173calm
183calm
193calm
203calm
213calm
223calm
233calm
243calm
253calm
263calm
273calm
283calm
293calm
303calm
313calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 54 min at the start of December to 9 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:43 AM to 7:00 AM, and sunset from 4:36 PM to 4:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.96:434:36
29.96:444:36
39.96:444:36
49.86:454:36
59.86:464:36
69.86:474:36
79.86:484:36
89.86:484:36
99.86:494:36
109.86:504:37
119.86:504:37
129.86:514:37
139.86:524:37
149.76:524:37
159.76:534:38
169.76:544:38
179.76:544:38
189.76:554:39
199.76:554:39
209.76:564:40
219.76:564:40
229.76:574:40
239.76:574:41
249.76:584:41
259.76:584:42
269.76:594:43
279.76:594:43
289.76:594:44
299.77:004:44
309.77:004:45
319.87:004:46

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.98 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.98 kWh/m² to a high of 8.15 kWh/m² in June across the year — December's 2.98 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.1Moderate
23.1Moderate
33.0Moderate
43.0Moderate
53.0Moderate
63.0Moderate
73.0Moderate
83.0Moderate
92.9Moderate
102.9Moderate
112.9Moderate
122.9Moderate
132.9Moderate
142.9Moderate
152.9Moderate
162.9Moderate
172.9Moderate
182.9Moderate
192.9Moderate
202.9Moderate
212.9Moderate
222.9Moderate
232.9Moderate
242.9Moderate
253.0Moderate
263.0Moderate
273.0Moderate
283.0Moderate
293.0Moderate
303.0Moderate
313.0Moderate
Planning a trip in December

Is December a good time to visit Fontana?

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

6.2
Sightseeing
7th-best month of the year
1.5
Beach & pool
12th-best month of the year

December is a reasonable time to visit Fontana for sightseeing.

What to pack for Fontana in December

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

In December, Fontana sees daytime highs around 62°F and nights near 42°F. Worth packing: a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Fontana in December

The nearest coast averages about 60°F in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 41 mi away) is warmest in August at about 69°F and coldest in February near 59°F.

It's comfortable for a long swim from Jul 13 to Sep 28 — about 2.6 months when the water holds above 68°F.

60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°F)Comfort
Jan59Cool
Feb59Cool
Mar59Cool
Apr60Cool
May63Cool
Jun65Cool
Jul68Refreshing
Aug69Refreshing
Sep69Refreshing
Oct67Cool
Nov64Cool
Dec60Cool

UV index in Fontana 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 Fontana peaks around July 12 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 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 highHighModerateJul 12UV 11Dec 16UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Fontana 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 Fontana is worst in September — around 49 µg/m³ PM2.5 (poor), about 4.0× the cleanest month (May, 12 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateSep 1447 µg/m³May 1713 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb19Moderate
Mar19Moderate
Apr17Moderate
May12Moderate
Jun17Moderate
Jul19Moderate
Aug32Moderate
Sep49Poor
Oct21Moderate
Nov21Moderate
Dec18Moderate
Location & terrain

Where is Fontana?

Fontana sits at 34.1°N, 117.4°W, 1,237 ft above sea level, in United States. The nearest listed city is Bloomington, 2.5 mi away.

Topography around Fontana

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

Within 2 miles, the terrain around Fontana has only modest variations in elevation — a maximum elevation change of 331 ft around an average of 1,230 ft above sea level; within 10 miles, very significant variations in elevation — a maximum elevation change of 5,686 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 11,417 ft.

The land around Fontana is covered by artificial surfaces (86%) within 2 miles, artificial surfaces (57%) within 10 miles, and shrubs (26%), artificial surfaces (22%) and grassland (20%) within 50 miles.

2 miles
331 ft
10 miles
5,686 ft
50 miles
11,417 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Bloomington 2.5 mi · Rialto 3.7 mi · Glen Avon 6.2 mi · Rubidoux 6.8 mi · Colton 6.8 mi · Jurupa Valley 8.1 mi · San Bernardino 8.1 mi · Rancho Cucamonga 9.3 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 Fontana (34.0922°, -117.4351°, elevation 1,237 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).