Jōetsu weather in December

In December, Jōetsu sees average daytime highs of 9°C and overnight lows near 4°C, with 247 mm of precipitation across 24.2 wet days and about 9.5 hours of daylight. It is the 10th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 11°C in the first days to 7°C by the end. The sky is clear or mostly clear about 10% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of December to 9 h 30 min by month's end. Set against the rest of the year, December is Jōetsu's 9th-clearest and 2nd-windiest month. For the whole year in context, see Jōetsu's year-round climate.

Daytime high
10th warmest
Overnight low
4th coldest
Precipitation
247 mm
24.2 wet days
Daylight
9 h 30 min
6:59 AM – 4:27 PM
Cloud cover
71%
9th clearest
Wind
15 km/h
2nd windiest
Solar energy
1.89 kWh/m²
Travel score
1.1
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 December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 11°C in the first days to 7°C by the end.

A typical December day in Jōetsu reaches about 9°C in the afternoon and slips back to 4°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 4°C and 13°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-5°10°15°20°151015202531
Avg high (°C)Avg low (°C)
1116
2116
3115
4115
5105
6105
7105
8105
9104
1094
1194
1294
1394
1494
1594
1684
1783
1883
1983
2083
2183
2283
2383
2473
2573
2673
2773
2872
2972
3072
3172

How December really feels in Jōetsu

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 16 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
16
wind chill below the day's low

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

Jōetsu weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 2nd-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 December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 19% of December, with mostly cloudy or overcast conditions the remaining 72%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13169
23070
32971
42971
52971
62971
72971
82872
92773
102773
112773
122773
132773
142773
152773
162872
172971
182971
192971
202971
212971
223070
232971
242971
252971
262971
272971
282971
292872
302773
312674

Chance of precipitation in December

Any precipitationSnow

Jōetsu gets around 247 mm of rain and snow over 24.2 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 78% and peaks near 82% on the wettest days, and about 8 days bring snow. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
1737
2748
3759
47510
57612
67713
77715
87817
97818
107820
117821
127823
137824
147825
157826
167728
177729
187730
197731
207732
217733
227834
237835
247936
257937
268038
278039
288140
298142
308243
318244

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December 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 December

Winds average 15 km/h in December.

Across December, daily wind ranges from about 14 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
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light 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
3017light breeze
3117light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 36 min at the start of December to 9 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:48 AM to 7:06 AM, and sunset from 4:26 PM to 4:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.66:484:26
29.66:494:26
39.66:504:26
49.66:504:25
59.66:514:25
69.66:524:25
79.56:534:25
89.56:544:25
99.56:554:26
109.56:554:26
119.56:564:26
129.56:574:26
139.56:574:26
149.56:584:26
159.56:594:27
169.56:594:27
179.57:004:27
189.57:014:28
199.47:014:28
209.47:024:28
219.47:024:29
229.47:034:29
239.47:034:30
249.47:044:30
259.47:044:31
269.57:044:31
279.57:054:32
289.57:054:33
299.57:054:33
309.57:064:34
319.57:064:35

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.89 kWh/m² — the year's lowest.

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 — December's 1.89 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.9Dim
21.9Dim
31.9Dim
41.9Dim
51.9Dim
61.9Dim
71.9Dim
81.9Dim
91.9Dim
101.9Dim
111.9Dim
121.9Dim
131.9Dim
141.9Dim
151.9Dim
161.9Dim
171.9Dim
181.9Dim
191.9Dim
201.9Dim
211.9Dim
221.9Dim
231.9Dim
242.0Dim
252.0Dim
262.0Dim
272.0Dim
282.0Moderate
292.0Moderate
302.0Moderate
312.0Moderate
Planning a trip in December

Hazard calendar for Jōetsu

In seasonPeak

In December, 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 December a good time to visit Jōetsu?

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

1.1
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Jōetsu.

What to pack for Jōetsu in December

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

In December, Jōetsu sees daytime highs around 9°C and nights near 4°C. Pack a warm layer and rain gear. About 24 days see rain.

a warm layerrain gear

Sea temperature near Jōetsu in December

The nearest coast averages about 15°C in December — 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 December

LowModerateHighVery highExtreme

Clear-sky midday UV in December 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 December

GoodModeratePoorUnhealthyVery unhealthy

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