San Jose weather in December

In December, San Jose sees average daytime highs of 57°F and overnight lows near 42°F, with 4.7 in of rain across 9.2 wet days and about 9.5 hours of daylight. It is the 12th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 57°F through the month. The sky is clear or mostly clear about 36% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of December to 9 h 30 min by month's end. Set against the rest of the year, December is San Jose's 9th-clearest and 5th-windiest month. For the whole year in context, see San Jose's year-round climate.

Daytime high
57°
12th warmest
Overnight low
42°
1st coldest
Rainfall
4.7 in
9.2 wet days
Daylight
9 h 24 min
7:21 AM – 4:47 PM
Cloud cover
56%
9th clearest
Wind
5 mph
5th windiest
Solar energy
2.34 kWh/m²
Travel score
4.2
out of 10

San Jose is city and county seat of Santa Clara County, California, United States.

Density
2,140/km²
people per km²
Founded
1777

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 57°F through the month.

A typical December day in San Jose reaches about 57°F in the afternoon and slips back to 42°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 64°F. Set against its neighbours, December runs about 6°F cooler than November and on par with January.

30°40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15944
25944
35943
45843
55843
65843
75843
85843
95843
105743
115743
125743
135742
145742
155742
165742
175742
185642
195642
205642
215642
225642
235641
245641
255641
265641
275641
285641
295641
305642
315642

San Jose 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 daysDaylight (hours)Travel score
Jan57° / 42°5.19.19.74.2
Feb59° / 44°5.39.310.64.6
Mar62° / 45°3.99.311.75.4
Apr65° / 47°1.85.612.96.7
May69° / 50°0.93.4147.8
Jun74° / 53°0.2114.59.1
Jul78° / 56°0.00.114.39.4
Aug78° / 56°0.00.213.49.2
Sep78° / 56°0.10.512.39.2
Oct73° / 52°1.23118.5
Nov63° / 46°2.46106.2
Dec57° / 42°4.79.29.54.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% 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 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15050
25050
35050
44951
54852
64753
74852
84753
94852
104753
114852
124753
134852
144852
155050
165050
175050
185149
195149
205149
215149
225248
235149
245149
255050
265050
274852
284753
294654
304753
314654

Chance of precipitation in December

Any precipitation

San Jose gets around 4.7 in of rain over 9.2 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
128
229
329
430
530
631
731
831
932
1032
1132
1232
1331
1431
1531
1630
1730
1829
1929
2029
2129
2228
2328
2428
2528
2628
2728
2828
2928
3028
3128

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1973
2973
3973
4973
5973
6973
7973
8973
9982
10982
11982
12982
13982
14982
15982
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27982
28982
29982
30982
31982

Wind in December

Winds average 5 mph in December.

Across December, daily wind ranges from about 4 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
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 36 min at the start of December to 9 h 30 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 7:09 AM to 7:27 AM, and sunset from 4:46 PM to 4:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.67:094:46
29.67:104:46
39.67:114:46
49.67:124:45
59.67:124:45
69.57:134:45
79.57:144:45
89.57:154:45
99.57:164:46
109.57:164:46
119.57:174:46
129.57:184:46
139.57:194:46
149.57:194:46
159.47:204:47
169.47:214:47
179.47:214:47
189.47:224:48
199.47:224:48
209.47:234:48
219.47:234:49
229.47:244:49
239.47:244:50
249.47:254:50
259.47:254:51
269.47:254:51
279.47:264:52
289.47:264:53
299.47:264:53
309.57:274:54
319.57:274:55

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.34 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.34 kWh/m² to a high of 7.85 kWh/m² in June across the year — December's 2.34 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.5Moderate
22.4Moderate
32.4Moderate
42.4Moderate
52.4Moderate
62.4Moderate
72.3Moderate
82.3Moderate
92.3Moderate
102.3Moderate
112.3Moderate
122.3Moderate
132.3Moderate
142.3Moderate
152.3Moderate
162.3Moderate
172.3Moderate
182.3Moderate
192.3Moderate
202.3Moderate
212.3Moderate
222.3Moderate
232.3Moderate
242.3Moderate
252.3Moderate
262.4Moderate
272.4Moderate
282.4Moderate
292.4Moderate
302.4Moderate
312.4Moderate
Planning a trip in December

Hazard calendar for San Jose

In seasonPeak

In December, San Jose sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

San Jose's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit San Jose?

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

4.2
Sightseeing
11th-best month of the year
0.0
Beach & pool
11th-best month of the year

December is a reasonable time to visit San Jose for sightseeing.

What to pack for San Jose in December

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

In December, San Jose sees daytime highs around 57°F and nights near 42°F. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near San Jose in December

The nearest coast averages about 55°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 27 mi away) is warmest in August at about 59°F and coldest in April near 54°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

52°54°56°58°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan54Bracing
Feb54Bracing
Mar54Bracing
Apr54Bracing
May54Bracing
Jun55Bracing
Jul57Bracing
Aug59Bracing
Sep59Bracing
Oct58Bracing
Nov56Bracing
Dec55Bracing

UV index in San Jose 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 San Jose peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 15UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in San Jose 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 San Jose is worst in August — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (June, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateAug 1824 µg/m³Jun 1110 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar16Moderate
Apr12Moderate
May10Good
Jun10Good
Jul11Good
Aug25Moderate
Sep17Moderate
Oct20Moderate
Nov18Moderate
Dec13Moderate
Location & terrain

Where is San Jose?

San Jose sits at 37.3°N, 121.9°W, 85 ft above sea level, in United States. The nearest listed city is Santa Clara, 3.7 mi away.

Topography around San Jose

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

Within 2 miles, the terrain around San Jose has only modest variations in elevation — a maximum elevation change of 115 ft around an average of 92 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,992 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,373 ft.

The land around San Jose is covered by artificial surfaces (79%) within 2 miles, artificial surfaces (54%), trees (20%) and grassland (20%) within 10 miles, and grassland (28%), water (28%) and trees (25%) within 50 miles.

2 miles
115 ft
10 miles
2,992 ft
50 miles
4,373 ft
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Santa Clara 3.7 mi · Alum Rock 4.3 mi · Campbell 5.0 mi · Milpitas 6.2 mi · Cupertino 7.5 mi · Sunnyvale 8.1 mi · Saratoga 8.7 mi · Los Gatos 8.7 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 San Jose (37.3394°, -121.895°, elevation 85 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).