San Diego weather in December

In December, San Diego sees average daytime highs of 29°C and overnight lows near 21°C, with 130 mm of rain across 16 wet days and about 11.4 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 34% of the time in December, and the air most often feels muggy.

Daylight stretches from about 11 h 24 min at the start of December to 11 h 24 min by month's end. Set against the rest of the year, December is San Diego's 3rd-clearest and 4th-windiest month. For the whole year in context, see San Diego's year-round climate.

Daytime high
29°
10th warmest
Overnight low
21°
3rd coldest
Rainfall
130 mm
16 wet days
Daylight
11 h 24 min
6:07 AM – 5:31 PM
Cloud cover
56%
3rd clearest
Wind
6 km/h
4th windiest
Solar energy
4.95 kWh/m²
Travel score
4.8
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical December day in San Diego reaches about 29°C in the afternoon and slips back to 21°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 31°C. Set against its neighbours, December runs on par with November and on par with January.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12921
22921
32921
42921
52921
62921
72921
82921
92921
102921
112921
122921
132921
142921
152921
162921
172921
182921
192921
202921
212921
222921
232921
242921
252921
262921
272921
282921
292921
302921
312921

How December really feels in San Diego

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

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

San Diego weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 20°53711.55.8
Feb30° / 21°74811.75.5
Mar30° / 21°18914.511.94.7
Apr29° / 22°41024.212.23.4
May29° / 23°56930.612.52.7
Jun30° / 22°38528.212.62.8
Jul30° / 22°26027.312.52.7
Aug30° / 22°37928.812.32.6
Sep30° / 22°47129.412.12.6
Oct29° / 22°5083011.82.9
Nov28° / 21°35526.311.53.5
Dec29° / 21°1301611.44.8

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 18% of December, with mostly cloudy or overcast conditions the remaining 47%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23664
33763
43961
53961
64060
74159
84258
94357
104357
114555
124654
134753
144852
154951
165149
175347
185545
195644
205842
216040
226139
236238
246436
256535
266733
276832
287030
297030
307129
317228

Chance of precipitation in December

Any precipitation

San Diego gets around 130 mm of rain over 16 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 52% and peaks near 71% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
171
270
368
467
566
664
763
862
961
1059
1158
1257
1355
1454
1553
1652
1750
1849
1948
2046
2145
2244
2342
2441
2540
2638
2737
2836
2935
3034
3133

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the muggy band about 67% of days. Sticky, muggy-or-worse air turns up on roughly 76% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1077122
2087220
3097219
40107218
50117217
60137116
70147016
80157015
90167014
100177013
110187012
121196812
131206811
141216810
151216810
16122689
17123688
18224677
19225676
20226675
21226675
22227674
23229663
24230653
25231643
26232642
27233632
28235612
29236611
30237601
31238591

Wind in December

Winds average 6 km/h in December.

Across December, daily wind ranges from about 5 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
297calm
307calm
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 h 24 min at the start of December to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over December. Sunrise moves from 5:59 AM to 6:14 AM, and sunset from 5:26 PM to 5:38 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.45:595:26
211.46:005:26
311.46:005:26
411.46:015:26
511.46:015:27
611.46:025:27
711.46:025:27
811.46:035:28
911.46:035:28
1011.46:045:28
1111.46:045:29
1211.46:055:29
1311.46:055:30
1411.46:065:30
1511.46:065:30
1611.46:075:31
1711.46:075:31
1811.46:085:32
1911.46:085:32
2011.46:095:33
2111.46:095:33
2211.46:105:34
2311.46:105:34
2411.46:115:35
2511.46:115:35
2611.46:125:35
2711.46:125:36
2811.46:135:36
2911.46:135:37
3011.46:135:37
3111.46:145:38

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.95 kWh/m².

For context, solar energy here swings from a low near 4.37 kWh/m² to a high of 5.87 kWh/m² in February across the year — December's 4.95 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.7Bright
34.7Bright
44.7Bright
54.7Bright
64.7Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.8Bright
124.9Bright
134.9Bright
144.9Bright
154.9Bright
164.9Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
225.1Bright
235.1Bright
245.1Bright
255.1Bright
265.2Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
315.2Bright
Planning a trip in December

Is December a good time to visit San Diego?

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

4.8
Sightseeing
3rd-best month of the year
6.1
Beach & pool
4th-best month of the year

December is a reasonable time to visit San Diego for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for San Diego in December

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

In December, San Diego sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 16 days see rain.

light clothesrain gearsun protection

UV index in San Diego in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Diego peaks around April 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 at about 10 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highApr 12UV 14Dec 12UV 10
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar13Extreme
Apr14Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec10Very high

Air quality in San Diego 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 Diego is worst in March — around 34 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (December, 9 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodMar 1832 µg/m³Dec 119 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb19Moderate
Mar34Moderate
Apr23Moderate
May20Moderate
Jun21Moderate
Jul21Moderate
Aug17Moderate
Sep13Moderate
Oct12Good
Nov10Good
Dec9Good
Location & terrain

Where is San Diego?

San Diego sits at 10.3°N, 73.2°W, 180 m above sea level, in Colombia. The nearest listed city is Valledupar, 17 km away.

Topography around San Diego

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Diego.

Within 3 km, the terrain around San Diego has only modest variations in elevation — a maximum elevation change of 215 m around an average of 170 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,747 m; within 80 km, extreme variations in elevation — a maximum elevation change of 5,632 m.

The land around San Diego is covered by grassland (49%) and trees (40%) within 3 km, trees (55%) and grassland (38%) within 16 km, and trees (64%) and grassland (31%) within 80 km.

3 km
215 m
16 km
1,747 m
80 km
5,632 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
December weather nearby: Valledupar 17 km · Agustín Codazzi 34 km · Villanueva 38 km · San Juan del Cesar 52 km · Becerril 71 km · Fonseca 71 km · Machiques 75 km · Barrancas 81 km

Colombia travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B
120 / 240 V · 60 Hz
Prices
≈ 38% of US
price level, 2025
GDP per capita
$8,562
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
74%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
15.4
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 480
Religion
Roman Catholic 64%Protestant 17%none 14%atheist 1%

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 Diego (10.3338°, -73.1805°, elevation 180 m), 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).