Uonuma weather in December

In December, Uonuma sees average daytime highs of 5°C and overnight lows near -2°C, with 271 mm of precipitation across 24 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 8°C in the first days to 3°C by the end. The sky is clear or mostly clear about 11% 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 Uonuma's 8th-clearest and 3rd-windiest month. For the whole year in context, see Uonuma's year-round climate.

Daytime high
10th warmest
Overnight low
-2°
3rd coldest
Precipitation
271 mm
24 wet days
Daylight
9 h 24 min
6:57 AM – 4:24 PM
Cloud cover
73%
8th clearest
Wind
8 km/h
3rd windiest
Solar energy
1.87 kWh/m²
Travel score
0.2
out of 10

Uonuma is city in Niigata Prefecture, Japan.

Density
36/km²
people per km²
Founded
2004

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 8°C in the first days to 3°C by the end.

A typical December day in Uonuma reaches about 5°C in the afternoon and slips back to -2°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 1°C and 10°C. Set against its neighbours, December runs about 7°C cooler than November and about 3°C warmer than January.

-10°-5°10°15°151015202531
Avg high (°C)Avg low (°C)
181
281
380
480
570
670
770
87-1
96-1
106-1
116-1
126-1
136-1
145-2
155-2
165-2
175-2
185-2
195-2
204-2
214-2
224-2
234-2
244-2
254-3
264-3
274-3
283-3
293-3
303-3
313-3

How December really feels in Uonuma

Once humidity and wind are folded in, December 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 December is cold — wind chill drags the overnight "feels like" below the raw low.

Uonuma 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 / -3°29826.224.19.70.0
Feb / -3°2232219.810.60.0
Mar / -1°20121.614.811.70.6
Apr14° / 14316.43.612.93.4
May20° / 10°152150.1145.5
Jun23° / 15°17816.6014.55.5
Jul27° / 20°26320.5014.34.7
Aug28° / 21°18017.8013.44.9
Sep24° / 17°19016.6012.35.5
Oct18° / 10°19616.60114.9
Nov12° / 19218.83.9102.5
Dec / -2°2712417.69.50.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 77%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12872
22773
32773
42773
52575
62575
72476
82476
92476
102476
112278
122278
132278
142377
152278
162377
172377
182377
192278
202278
212278
222278
232377
242278
252179
262179
272179
282080
292080
301981
311981

Chance of precipitation in December

Any precipitationSnow

Uonuma gets around 271 mm of rain and snow over 24 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 77% and peaks near 83% on the wettest days, and about 18 days bring snow. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
17032
27134
37236
47339
57441
67443
77545
87648
97650
107652
117753
127755
137756
147757
157758
167759
177759
187760
197761
207862
217862
227863
237964
247965
258066
268067
278168
288169
298270
308272
318373

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 8 km/h in December.

Across December, daily wind ranges from about 7 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
17calm
27calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

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 6:45 AM to 7:03 AM, and sunset from 4:23 PM to 4:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.66:454:23
29.66:464:22
39.66:474:22
49.66:484:22
59.66:494:22
69.56:504:22
79.56:504:22
89.56:514:22
99.56:524:22
109.56:534:23
119.56:534:23
129.56:544:23
139.56:554:23
149.56:564:23
159.56:564:24
169.46:574:24
179.46:574:24
189.46:584:24
199.46:594:25
209.46:594:25
219.47:004:26
229.47:004:26
239.47:014:27
249.47:014:27
259.47:014:28
269.47:024:28
279.47:024:29
289.47:024:29
299.57:034:30
309.57:034:31
319.57:034:31

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.87 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.87 kWh/m² to a high of 5.55 kWh/m² in May across the year — December's 1.87 kWh/m² sits near the bottom.

00.511.522.5151015202531
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
241.9Dim
251.9Dim
261.9Dim
271.9Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Hazard calendar for Uonuma

In seasonPeak

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

Uonuma 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 Uonuma?

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

0.2
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 Uonuma.

What to pack for Uonuma in December

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

In December, Uonuma sees daytime highs around 5°C and nights near -2°C. Pack a warm layer and rain gear. Worth having: a heavy coat. About 24 days see rain.

a warm layerrain geara heavy coat

Sea temperature near Uonuma 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 at the nearest coast (about 33 km away) is warmest in August at about 27°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
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Cool

UV index in Uonuma 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 Uonuma peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Dec 21UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Uonuma 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 Uonuma 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 Uonuma?

Uonuma sits at 37.2°N, 139.0°E, 95 m above sea level, in Japan. The nearest listed city is Ojiya, 16 km away.

Topography around Uonuma

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

Within 3 km, the terrain around Uonuma has significant variations in elevation — a maximum elevation change of 251 m around an average of 138 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,713 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,554 m.

The land around Uonuma is covered by trees (43%), cropland (29%) and artificial surfaces (21%) within 3 km, trees (82%) within 16 km, and trees (70%) within 80 km.

3 km
251 m
16 km
1,713 m
80 km
2,554 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Ojiya 16 km · Minamiuonuma 20 km · Muikamachi 21 km · Tōkamachi 21 km · Nagaoka 25 km · Shiozawa 25 km · Tochio-honchō 26 km · Mitsuke 32 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 Uonuma (37.2449°, 138.9623°, elevation 95 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).