Sanjō weather in January

In January, Sanjō sees average daytime highs of 4°C and overnight lows near -2°C, with 205 mm of precipitation across 25.7 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 4°C through the month. The sky is clear or mostly clear about 4% 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 Sanjō's 12th-clearest and 2nd-windiest month. For the whole year in context, see Sanjō's year-round climate.

Daytime high
12th warmest
Overnight low
-2°
2nd coldest
Precipitation
205 mm
25.7 wet days
Daylight
9 h 42 min
7:03 AM – 4:44 PM
Cloud cover
79%
12th clearest
Wind
9 km/h
2nd windiest
Solar energy
2.04 kWh/m²
Travel score
0.0
out of 10

Sanjō is city in Niigata Prefecture, Japan.

Density
219/km²
people per km²
Founded
1934

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 4°C through the month.

A typical January day in Sanjō reaches about 4°C in the afternoon and slips back to -2°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 1°C and 7°C. Set against its neighbours, January runs about 3°C cooler than December and about 1°C cooler than February.

-10°-5°10°151015202531
Avg high (°C)Avg low (°C)
15-1
24-2
34-2
44-2
54-2
64-2
74-2
84-2
94-2
104-2
114-2
124-2
134-2
144-2
154-2
164-2
174-2
184-2
194-2
204-2
214-2
224-2
234-2
244-2
254-2
264-2
274-2
284-2
294-2
304-2
314-2

How January really feels in Sanjō

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 31 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
31
wind chill below the day's low

The story in January is cold — wind chill drags the overnight "feels like" below the raw low.

Sanjō 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 (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -2°20525.720.79.70.0
Feb / -2°14921.517.210.50.1
Mar / 15020.810.611.71.3
Apr16° / 11615.31.312.94.3
May22° / 11°11613.10146.1
Jun25° / 16°14314.1014.55.8
Jul28° / 21°24417.7014.34.6
Aug30° / 22°16915.7013.44.3
Sep26° / 17°15615.1012.35.6
Oct20° / 11°15715.80115.4
Nov13° / 15318.51.3103.0
Dec / -0°2022412.89.40.6

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 4% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 10% of January, with mostly cloudy or overcast conditions the remaining 86%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11684
21585
31585
41585
51585
61585
71585
81585
91486
101486
111486
121486
131486
141486
151486
161486
171486
181387
191387
201387
211288
221288
231288
241288
251387
261387
271387
281387
291486
301486
311486

Chance of precipitation in January

Any precipitationSnow

Sanjō gets around 205 mm of rain and snow over 25.7 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 83% and peaks near 84% on the wettest days, and about 21 days bring snow.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
18259
28360
38361
48362
58362
68363
78463
88463
98364
108364
118365
128365
138365
148366
158266
168267
178267
188268
198268
208269
218269
228270
238270
248371
258372
268372
278373
288373
298373
308373
318272

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in January

Winds average 9 km/h in January.

Across January, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

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 7:04 AM to 6:56 AM, and sunset from 4:31 PM to 4:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:044:31
29.57:044:31
39.57:044:32
49.57:054:33
59.57:054:34
69.57:054:34
79.57:054:35
89.57:054:36
99.57:054:37
109.67:054:38
119.67:044:39
129.67:044:40
139.67:044:41
149.67:044:42
159.67:044:43
169.77:034:44
179.77:034:45
189.77:034:46
199.77:024:47
209.87:024:48
219.87:024:49
229.87:014:50
239.87:014:51
249.97:004:52
259.97:004:53
269.96:594:54
279.96:594:55
2810.06:584:56
2910.06:574:57
3010.06:574:58
3110.16:564:59

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.04 kWh/m².

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 5.54 kWh/m² in May across the year — January's 2.04 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.9Dim
71.9Dim
81.9Dim
91.9Dim
101.9Dim
111.9Dim
121.9Dim
131.9Dim
142.0Dim
152.0Dim
162.0Moderate
172.0Moderate
182.1Moderate
192.1Moderate
202.1Moderate
212.1Moderate
222.2Moderate
232.2Moderate
242.2Moderate
252.2Moderate
262.3Moderate
272.3Moderate
282.3Moderate
292.4Moderate
302.4Moderate
312.4Moderate
Planning a trip in January

Hazard calendar for Sanjō

In seasonPeak

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

Sanjō sits in the Pacific typhoon belt; the season peaks July–October.

Pacific typhoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is January a good time to visit Sanjō?

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

0.0
Sightseeing
12th-best month of the year
0.0
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Sanjō.

What to pack for Sanjō in January

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

In January, Sanjō sees daytime highs around 4°C and nights near -2°C. Pack a warm layer and rain gear. Worth having: a heavy coat. About 26 days see rain.

a warm layerrain geara heavy coat

Sea temperature near Sanjō in January

The nearest coast averages about 12°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 29 km away) is warmest in August at about 26°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 21 to Oct 31 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun19Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Cool

UV index in Sanjō 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 Sanjō peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul9Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Sanjō 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 Sanjō is worst in April — around 23 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1723 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb15Moderate
Mar22Moderate
Apr23Moderate
May22Moderate
Jun19Moderate
Jul17Moderate
Aug14Moderate
Sep12Moderate
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Sanjō?

Sanjō sits at 37.6°N, 138.9°E, 9 m above sea level, in Japan. The nearest listed city is Tsubame, 6.0 km away.

Topography around Sanjō

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

Within 3 km, the terrain around Sanjō has only modest variations in elevation — a maximum elevation change of 117 m around an average of 12 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 626 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,314 m.

The land around Sanjō is covered by artificial surfaces (45%) and cropland (40%) within 3 km, cropland (43%) and trees (38%) within 16 km, and trees (52%) and water (36%) within 80 km.

3 km
117 m
16 km
626 m
80 km
2,314 m
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Tsubame 6.0 km · Kamo 9.0 km · Mitsuke 9.0 km · Yoshida-kasugachō 9.0 km · Maki 16 km · Tochio-honchō 16 km · Shirone 18 km · Nagaoka 21 km

Japan travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
100 V · 50 / 60 Hz
Prices
≈ 65% of US
price level, 2025
GDP per capita
$35,951
2025
Happiness
6.1 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.2
per 100k, 2023
Road deaths
3.6
per 100k/yr, 2019
Income group
High
World Bank
English
Very low
EF EPI 446
Religion
Shintoism 49%Buddhism 46%other 4%Christianity 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 Sanjō (37.6167°, 138.95°, elevation 9 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).