Pacifica weather in January

In January, Pacifica sees average daytime highs of 55°F and overnight lows near 48°F, with 4.0 in of rain across 10 wet days and about 9.7 hours of daylight. It is the 12th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 55°F through the month. The sky is clear or mostly clear about 32% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of January to 10 h 06 min by month's end. Set against the rest of the year, January is Pacifica's 12th-clearest and 8th-windiest month. For the whole year in context, see Pacifica's year-round climate.

Daytime high
55°
12th warmest
Overnight low
48°
1st coldest
Rainfall
4.0 in
10 wet days
Daylight
9 h 42 min
7:29 AM – 5:09 PM
Cloud cover
60%
12th clearest
Wind
8 mph
8th windiest
Solar energy
2.44 kWh/m²
Travel score
3.6
out of 10

Pacifica is city in San Mateo County, California, USA.

Density
1,197/km²
people per km²
Founded
1957

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 55°F through the month.

A typical January day in Pacifica reaches about 55°F in the afternoon and slips back to 48°F overnight — a 7°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 59°F. Set against its neighbours, January runs on par with December and on par with February.

40°50°60°70°151015202531
Avg high (°F)Avg low (°F)
15548
25548
35548
45548
55548
65548
75548
85548
95548
105548
115548
125548
135548
145548
155548
165548
175548
185548
195548
205548
215548
225548
235548
245648
255649
265649
275649
285649
295649
305649
315649

Pacifica weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan55° / 48°4.0109.73.6
Feb56° / 49°4.29.410.53.8
Mar57° / 50°3.19.311.74.2
Apr58° / 51°1.55.312.94.8
May59° / 52°0.73.1145.5
Jun61° / 54°0.20.814.56.5
Jul63° / 55°0.00.114.37.1
Aug64° / 57°0.00.113.47.5
Sep65° / 57°0.10.512.37.7
Oct64° / 55°0.93.1117.1
Nov59° / 52°2.16.2105.1
Dec56° / 49°4.09.89.43.7

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 11% of January, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24357
34258
44258
54159
64159
74159
84159
94258
104159
114159
124258
134357
144357
154357
164357
174357
184357
194456
204456
214456
224456
234555
244456
254456
264555
274654
284654
294555
304555
314654

Chance of precipitation in January

Any precipitation

Pacifica gets around 4.0 in of rain over 10 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 32% and peaks near 33% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
131
231
331
432
532
632
732
832
932
1032
1132
1232
1332
1432
1532
1633
1733
1833
1933
2033
2133
2233
2333
2433
2532
2632
2732
2831
2931
3030
3130

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1982
2982
3982
4982
5982
6982
7982
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991
31991

Wind in January

Winds average 8 mph in January.

Across January, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 24 min at the start of January to 10 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over January. Sunrise moves from 7:30 AM to 7:22 AM, and sunset from 4:56 PM to 5:25 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:304:56
29.57:304:57
39.57:304:58
49.57:304:59
59.57:304:59
69.57:305:00
79.57:305:01
89.57:305:02
99.57:305:03
109.67:305:04
119.67:305:05
129.67:305:05
139.67:305:06
149.67:305:07
159.67:295:08
169.77:295:09
179.77:295:10
189.77:295:11
199.77:285:12
209.87:285:13
219.87:275:14
229.87:275:15
239.87:265:16
249.97:265:17
259.97:255:18
269.97:255:20
279.97:245:21
2810.07:245:22
2910.07:235:23
3010.07:225:24
3110.17:225:25

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.44 kWh/m².

For context, solar energy here swings from a low near 2.25 kWh/m² to a high of 7.64 kWh/m² in June across the year — January's 2.44 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.3Moderate
22.3Moderate
32.3Moderate
42.3Moderate
52.3Moderate
62.3Moderate
72.3Moderate
82.3Moderate
92.3Moderate
102.3Moderate
112.3Moderate
122.4Moderate
132.4Moderate
142.4Moderate
152.4Moderate
162.4Moderate
172.5Moderate
182.5Moderate
192.5Moderate
202.5Moderate
212.6Moderate
222.6Moderate
232.6Moderate
242.6Moderate
252.7Moderate
262.7Moderate
272.7Moderate
282.8Moderate
292.8Moderate
302.8Moderate
312.9Moderate
Planning a trip in January

Hazard calendar for Pacifica

In seasonPeak

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

Pacifica'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 January a good time to visit Pacifica?

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

3.6
Sightseeing
12th-best month of the year
0.0
Beach & pool
8th-best month of the year

January is a weaker month for outdoor sightseeing in Pacifica.

What to pack for Pacifica in January

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

In January, Pacifica sees daytime highs around 55°F and nights near 48°F. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Pacifica in January

The nearest coast averages about 53°F in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in September at about 58°F and coldest in April near 53°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
Jan53Bracing
Feb54Bracing
Mar54Bracing
Apr53Bracing
May53Bracing
Jun54Bracing
Jul56Bracing
Aug58Bracing
Sep58Bracing
Oct57Bracing
Nov56Bracing
Dec54Bracing

UV index in Pacifica in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Pacifica 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
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Extreme
Jul10Extreme
Aug10Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Moderate

Air quality in Pacifica 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 Pacifica 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 Pacifica?

Pacifica sits at 37.6°N, 122.5°W, 82 ft above sea level, in United States. The nearest listed city is San Bruno, 4.3 mi away.

Topography around Pacifica

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

Within 2 miles, the terrain around Pacifica has significant variations in elevation — a maximum elevation change of 1,263 ft around an average of 302 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 1,991 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,383 ft.

The land around Pacifica is covered by trees (40%) and water (29%) within 2 miles, water (56%) and trees (21%) within 10 miles, and water (45%), trees (21%) and grassland (20%) within 50 miles.

2 miles
1,263 ft
10 miles
1,991 ft
50 miles
4,383 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
January weather nearby: San Bruno 4.3 mi · South San Francisco 5.0 mi · Millbrae 5.6 mi · Daly City 6.2 mi · Burlingame 6.8 mi · Visitacion Valley 8.7 mi · Parkside 8.7 mi · San Mateo 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 Pacifica (37.6138°, -122.4869°, elevation 82 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).