San Francisco weather in January

In January, San Francisco sees average daytime highs of 30°C and overnight lows near 19°C, with 119 mm of rain across 9.1 wet days and about 13.8 hours of daylight. It is the 1st-warmest and 3rd-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 49% of the time in January, and the air most often feels muggy.

Daylight stretches from about 14 hours at the start of January to 13 h 30 min by month's end. Set against the rest of the year, January is San Francisco's 5th-clearest and 10th-windiest month. For the whole year in context, see San Francisco's year-round climate.

Daytime high
30°
1st warmest
Overnight low
19°
12th coldest
Rainfall
119 mm
9.1 wet days
Daylight
13 h 48 min
6:22 AM – 8:13 PM
Cloud cover
44%
5th clearest
Wind
11 km/h
10th windiest
Solar energy
7.1 kWh/m²
Travel score
5.3
out of 10

San Francisco is city in Argentina.

Founded
1886

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 30°C through the month.

A typical January day in San Francisco reaches about 30°C in the afternoon and slips back to 19°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 34°C. Set against its neighbours, January runs on par with December and about 1°C warmer than February.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13019
23019
33019
43020
53020
63019
73019
83019
93019
103019
113019
123019
133019
143019
153019
163019
173019
183019
193019
203019
213019
223019
233019
243019
253019
263019
273019
283019
293019
303019
312919

San Francisco weather by month

How January compares with the rest of the year at a glance. January is the 1st-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 19°1199.113.85.3
Feb29° / 19°1159.113.15.8
Mar27° / 17°1389.212.26.8
Apr24° / 14°1008.211.37.4
May20° / 11°475.510.47.1
Jun18° / 304.3106.6
Jul17° / 203.510.26.7
Aug20° / 393.810.97.6
Sep22° / 11°515.411.87.8
Oct25° / 14°1169.612.87.2
Nov28° / 16°1198.913.66.6
Dec30° / 18°1289.6145.5

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 17% of January, with mostly cloudy or overcast conditions the remaining 34%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16337
26337
36436
46436
56436
66535
76436
86535
96535
106634
116535
126535
136634
146634
156634
166634
176634
186733
196733
206733
216733
226832
236832
246832
256832
266832
276832
286634
296634
306634
316634

Chance of precipitation in January

Any precipitation

San Francisco gets around 119 mm of rain over 9.1 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 29% and peaks near 33% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
132
232
331
431
531
631
730
830
929
1029
1128
1228
1328
1427
1527
1627
1727
1827
1927
2028
2128
2228
2328
2429
2530
2630
2731
2832
2932
3032
3133

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the muggy band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 53% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
17172232201
27172232201
37172232211
47162232211
57162232211
67162332211
78162332211
88152332201
98152432201
108142532201
118142532201
128132633191
138132733191
148132733181
158122834181
167122834181
177122935171
187112935171
197113035161
206113035161
216113036161
226113036161
236113036161
245123036161
255122936161
265122936171
275122836171
285132836171
295132835182
305132735182
315132734192

Wind in January

Winds average 11 km/h in January.

Across January, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 14 hours at the start of January to 13 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 30 minutes over January. Sunrise moves from 6:11 AM to 6:36 AM, and sunset from 8:12 PM to 8:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.06:118:12
214.06:128:12
314.06:128:12
414.06:138:13
514.06:148:13
614.06:158:13
714.06:158:13
813.96:168:13
913.96:178:13
1013.96:188:13
1113.96:188:13
1213.96:198:13
1313.96:208:13
1413.96:218:13
1513.96:228:13
1613.86:228:13
1713.86:238:13
1813.86:248:12
1913.86:258:12
2013.86:268:12
2113.76:278:12
2213.76:288:11
2313.76:298:11
2413.76:298:11
2513.76:308:10
2613.66:318:10
2713.66:328:10
2813.66:338:09
2913.66:348:09
3013.66:358:08
3113.56:368:08

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 7.1 kWh/m².

For context, solar energy here swings from a low near 2.55 kWh/m² to a high of 7.19 kWh/m² in December across the year — January's 7.1 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.1Intense
27.1Intense
37.1Intense
47.1Intense
57.2Intense
67.2Intense
77.2Intense
87.2Intense
97.2Intense
107.2Intense
117.2Intense
127.2Intense
137.2Intense
147.2Intense
157.2Intense
167.2Intense
177.2Intense
187.2Intense
197.1Intense
207.1Intense
217.1Intense
227.0Intense
237.0Intense
247.0Intense
257.0Intense
266.9Intense
276.9Intense
286.8Intense
296.8Intense
306.7Intense
316.7Intense
Planning a trip in January

Is January a good time to visit San Francisco?

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

5.3
Sightseeing
12th-best month of the year
7.2
Beach & pool
1st-best month of the year

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

What to pack for San Francisco in January

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

In January, San Francisco sees daytime highs around 30°C and nights near 19°C. Pack light clothes and sun protection. Worth having: rain gear. About 9 days see rain.

light clothessun protectionrain gear

UV index in San Francisco in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 14 (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 Francisco peaks around January 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeModerateHighVery highExtremeJan 17UV 14Jun 21UV 3
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar11Extreme
Apr7High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug5Moderate
Sep7High
Oct10Very high
Nov11Extreme
Dec13Extreme
Location & terrain

Where is San Francisco?

San Francisco sits at 31.4°S, 62.1°W, 120 m above sea level, in Argentina. The nearest listed city is San Jorge, 57 km away.

Topography around San Francisco

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

Within 3 km, the terrain around San Francisco has only modest variations in elevation — a maximum elevation change of 13 m around an average of 114 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 24 m; within 80 km, only modest variations in elevation — a maximum elevation change of 103 m.

The land around San Francisco is covered by artificial surfaces (50%) and cropland (30%) within 3 km, cropland (94%) within 16 km, and cropland (88%) within 80 km.

3 km
13 m
16 km
24 m
80 km
103 m
treesgrasslandcroplandartificial surfaceswater
January weather nearby: San Jorge 57 km · Rafaela 60 km · Sunchales 73 km · Las Varillas 78 km · Morteros 80 km · Arroyito 92 km · Gálvez 106 km · Esperanza 109 km

Argentina travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / I
220 V · 50 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$14,898
2025
Happiness
6.4 / 10
World Happiness, 2025
Homicide rate
4.5
per 100k, 2023
Road deaths
14.1
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 575
Religion
Roman Catholic 63%none 19%Evangelical 15%Jehovah's Witness and Church of Jesus Christ 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 Francisco (-31.425°, -62.084°, elevation 120 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).