Jōetsu weather in January

In January, Jōetsu sees average daytime highs of 6°C and overnight lows near 1°C, with 253 mm of precipitation across 25.9 wet days and about 9.7 hours of daylight. It is the 12th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 6°C through the month. The sky is clear or mostly clear about 5% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 30 min at the start of January to 10 h 06 min by month's end. Set against the rest of the year, January is Jōetsu's 12th-clearest and 1st-windiest month. For the whole year in context, see Jōetsu's year-round climate.

Daytime high
12th warmest
Overnight low
2nd coldest
Precipitation
253 mm
25.9 wet days
Daylight
9 h 42 min
7:05 AM – 4:48 PM
Cloud cover
74%
12th clearest
Wind
16 km/h
1st windiest
Solar energy
2.3 kWh/m²
Travel score
0.2
out of 10

Jōetsu is city in Niigata Prefecture, Japan.

Density
195/km²
people per km²
Founded
1971

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 6°C through the month.

A typical January day in Jōetsu reaches about 6°C in the afternoon and slips back to 1°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 2°C and 9°C. Set against its neighbours, January runs about 3°C cooler than December and on par with February.

-5°10°15°151015202531
Avg high (°C)Avg low (°C)
172
262
362
462
562
662
762
862
962
1062
1162
1261
1361
1461
1551
1651
1751
1851
1951
2051
2151
2251
2351
2451
2551
2651
2751
2851
2951
3051
3151

How January really feels in Jōetsu

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.

Jōetsu weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 25325.916.39.70.2
Feb / 17821.213.310.60.3
Mar10° / 14519.66.511.71.6
Apr15° / 9713.40.412.94.3
May20° / 13°9211.60146.1
Jun24° / 18°11511.5014.56.4
Jul28° / 22°19114.4014.35.3
Aug30° / 24°12212.1013.44.9
Sep26° / 20°16214.1012.35.8
Oct20° / 14°16415.10115.6
Nov14° / 18018.50.3103.4
Dec / 24724.28.49.51.1

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 5% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 19% of January, with mostly cloudy or overcast conditions the remaining 76%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12674
22575
32575
42575
52377
62377
72278
82278
92278
102278
112278
122179
132179
142179
152179
162179
172179
182278
192377
202377
212476
222476
232575
242575
252575
262674
272674
282674
292773
302773
312773

Chance of precipitation in January

Any precipitationSnow

Jōetsu gets around 253 mm of rain and snow over 25.9 wet days in January, the wettest month. 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 16 days bring snow.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
18345
28346
38446
48447
58447
68448
78448
88448
98449
108449
118450
128350
138350
148351
158352
168352
178253
188254
198254
208355
218355
228356
238357
248357
258458
268458
278458
288459
298459
308458
318458

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 16 km/h in January, the windiest month of the year.

Across January, daily wind ranges from about 15 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3116light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 30 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 36 minutes over January. Sunrise moves from 7:06 AM to 6:58 AM, and sunset from 4:35 PM to 5:03 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.57:064:35
29.57:064:36
39.57:064:36
49.57:064:37
59.57:064:38
69.57:064:39
79.67:064:39
89.67:064:40
99.67:064:41
109.67:064:42
119.67:064:43
129.67:064:44
139.77:064:45
149.77:064:46
159.77:054:47
169.77:054:48
179.77:054:49
189.87:044:50
199.87:044:51
209.87:044:52
219.87:034:53
229.87:034:54
239.97:024:55
249.97:024:56
259.97:014:57
269.97:014:58
2710.07:004:59
2810.07:005:00
2910.06:595:01
3010.16:585:02
3110.16:585:03

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.3 kWh/m².

For context, solar energy here swings from a low near 1.89 kWh/m² to a high of 5.79 kWh/m² in May across the year — January's 2.3 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.0Moderate
22.0Moderate
32.1Moderate
42.1Moderate
52.1Moderate
62.1Moderate
72.1Moderate
82.1Moderate
92.1Moderate
102.1Moderate
112.1Moderate
122.2Moderate
132.2Moderate
142.2Moderate
152.2Moderate
162.3Moderate
172.3Moderate
182.3Moderate
192.3Moderate
202.4Moderate
212.4Moderate
222.4Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.6Moderate
272.6Moderate
282.6Moderate
292.7Moderate
302.7Moderate
312.7Moderate
Planning a trip in January

Hazard calendar for Jōetsu

In seasonPeak

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

Jōetsu 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 Jōetsu?

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

0.2
Sightseeing
12th-best month of the year
0.0
Beach & pool
9th-best month of the year

January is a weaker month for outdoor sightseeing in Jōetsu.

What to pack for Jōetsu in January

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

In January, Jōetsu sees daytime highs around 6°C and nights near 1°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 Jōetsu in January

The nearest coast averages about 13°C 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 August at about 27°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 20 to Nov 1 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec15Cool

UV index in Jōetsu 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 Jōetsu peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 highModerateAug 12UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul9Very high
Aug10Very high
Sep9Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Jōetsu 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 Jōetsu is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1521 µg/m³Dec 149 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr22Moderate
May20Moderate
Jun17Moderate
Jul15Moderate
Aug12Good
Sep10Good
Oct10Good
Nov10Good
Dec9Good
Location & terrain

Where is Jōetsu?

Jōetsu sits at 37.1°N, 138.2°E, 10 m above sea level, in Japan. The nearest listed city is Myoko, 14 km away.

Topography around Jōetsu

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

Within 3 km, the terrain around Jōetsu has only modest variations in elevation — a maximum elevation change of 177 m around an average of 22 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,200 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,900 m.

The land around Jōetsu is covered by artificial surfaces (46%), trees (24%) and cropland (20%) within 3 km, trees (39%) and water (32%) within 16 km, and trees (53%) and water (37%) within 80 km.

3 km
177 m
16 km
1,200 m
80 km
2,900 m
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Myoko 14 km · Arai 16 km · Iiyama 35 km · Itoigawa 37 km · Kashiwazaki 37 km · Nakano 46 km · Tōkamachi 47 km · Ojiya 53 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 Jōetsu (37.1483°, 138.2364°, elevation 10 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).