San Diego weather in January

In January, San Diego sees average daytime highs of 30°C and overnight lows near 20°C, with 53 mm of rain across 7 wet days and about 11.5 hours of daylight. It is the 7th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 59% of the time in January, and the air most often feels humid.

Daylight stretches from about 11 h 24 min at the start of January to 11 h 30 min by month's end. Set against the rest of the year, January is San Diego's 1st-clearest and 2nd-windiest month. For the whole year in context, see San Diego's year-round climate.

Daytime high
30°
7th warmest
Overnight low
20°
1st coldest
Rainfall
53 mm
7 wet days
Daylight
11 h 30 min
6:18 AM – 5:46 PM
Cloud cover
39%
1st clearest
Wind
7 km/h
2nd windiest
Solar energy
5.49 kWh/m²
Travel score
5.8
out of 10

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical January day in San Diego reaches about 30°C in the afternoon and slips back to 20°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 31°C. Set against its neighbours, January runs on par with December and on par with February.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12921
22920
32920
42920
52920
62920
72920
82920
92920
102920
112920
122920
132920
142920
152920
163020
173020
183020
193020
203020
213020
223020
233020
243020
253020
263020
273020
283020
293020
303020
313020

How January really feels in San Diego

Once humidity and wind are folded in, January 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

January 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 January compares with the rest of the year at a glance. January is the 7th-warmest and 12th-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 January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in January, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of January, with mostly cloudy or overcast conditions the remaining 23%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17327
27426
37426
47525
57525
67624
77624
87723
97723
107723
117723
127723
137723
147723
157624
167624
177624
187723
197723
207723
217723
227723
237723
247822
257822
267822
277822
287822
297822
307822
317822

Chance of precipitation in January

Any precipitation

San Diego gets around 53 mm of rain over 7 wet days in January, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 24% and peaks near 32% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
132
231
330
430
529
628
728
827
926
1026
1125
1225
1324
1424
1523
1623
1722
1821
1921
2020
2120
2219
2319
2419
2519
2619
2719
2820
2920
3021
3122

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the humid band about 48% of days. Sticky, muggy-or-worse air turns up on roughly 46% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1239581
2240571
3341560
4342550
5343540
6443530
7444520
8445510
9446500
10546490
11547480
12548470
13549460
14649450
15650440
16650440
17651430
18751420
19751420
20751420
21751420
22752410
23851410
24851410
25851410
26951400
27951400
28952390
29951391
30952381
31952381

Wind in January

Winds average 7 km/h in January.

Across January, daily wind ranges from about 7 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
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 11 h 24 min at the start of January to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over January. Sunrise moves from 6:14 AM to 6:20 AM, and sunset from 5:38 PM to 5:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.46:145:38
211.46:145:39
311.46:145:39
411.46:155:40
511.46:155:40
611.46:165:41
711.46:165:41
811.46:165:42
911.46:175:42
1011.46:175:43
1111.46:175:43
1211.46:175:44
1311.46:185:44
1411.46:185:45
1511.56:185:45
1611.56:185:46
1711.56:195:46
1811.56:195:47
1911.56:195:47
2011.56:195:48
2111.56:195:48
2211.56:195:49
2311.56:195:49
2411.56:205:49
2511.56:205:50
2611.56:205:50
2711.56:205:51
2811.56:205:51
2911.56:205:52
3011.56:205:52
3111.56:205:52

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 5.49 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 — January's 5.49 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.4Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.7Bright
265.7Bright
275.7Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in January

Is January a good time to visit San Diego?

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

5.8
Sightseeing
1st-best month of the year
7.7
Beach & pool
1st-best month of the year

January 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 January

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

In January, San Diego sees daytime highs around 30°C and nights near 20°C. Pack light clothes. Worth having: sun protection. About 7 days see rain.

light clothessun protection

UV index in San Diego in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 11 (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 January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January 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
January 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).