Semboku weather in December

In December, Semboku sees average daytime highs of 2°C and overnight lows near -5°C, with 130 mm of precipitation across 19.4 wet days and about 9.2 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 4°C in the first days to 0°C by the end. The sky is clear or mostly clear about 6% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of December to 9 h 12 min by month's end. Set against the rest of the year, December is Semboku's 10th-clearest and 5th-windiest month. For the whole year in context, see Semboku's year-round climate.

Daytime high
10th warmest
Overnight low
-5°
3rd coldest
Precipitation
130 mm
19.4 wet days
Daylight
9 h 12 min
6:57 AM – 4:09 PM
Cloud cover
75%
10th clearest
Wind
9 km/h
5th windiest
Solar energy
1.73 kWh/m²
Travel score
0.0
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 4°C in the first days to 0°C by the end.

A typical December day in Semboku reaches about 2°C in the afternoon and slips back to -5°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between -3°C and 6°C. Set against its neighbours, December runs about 7°C cooler than November and about 3°C warmer than January.

-15°-10°-5°10°151015202531
Avg high (°C)Avg low (°C)
14-2
24-2
34-3
44-3
53-3
63-3
73-4
83-4
92-4
102-4
112-4
122-5
132-5
142-5
151-5
161-5
171-5
181-5
191-5
201-6
211-6
221-6
231-6
241-6
250-6
260-6
270-6
280-6
290-6
300-6
310-6

How December really feels in Semboku

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
7 feel bitter (≤ -10°C)

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

Semboku weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -8°10718.322.19.50.0
Feb / -7°9816.118.310.40.0
Mar / -4°13418.316.211.70.1
Apr10° / 13315.95132.1
May17° / 150150.114.24.6
Jun21° / 13°15815.1014.85.3
Jul24° / 18°25019.6014.55.2
Aug25° / 19°21617.9013.65.4
Sep21° / 14°18715.8012.35.4
Oct15° / 159150.310.94.1
Nov / 13717.66.49.81.2
Dec / -5°13019.419.29.20.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 6% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 79%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12575
22476
32476
42377
52278
62278
72278
82278
92278
102179
112179
122179
132080
142080
152080
162080
172080
182179
192179
202179
212179
222179
232179
242179
252179
262179
272080
282080
292080
302080
311981

Chance of precipitation in December

Any precipitationSnow

Semboku gets around 130 mm of rain and snow over 19.4 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 63% and peaks near 64% on the wettest days, and about 19 days bring snow.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
16044
26046
36047
46149
56151
66153
76255
86256
96358
106359
116460
126461
136462
146463
156463
166464
176464
186464
196465
206465
216466
226466
236467
246467
256468
266468
276469
286470
296471
306472
316473

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 9 km/h in December.

Across December, daily wind ranges from about 8 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
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 24 min at the start of December to 9 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 6:45 AM to 7:03 AM, and sunset from 4:09 PM to 4:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.46:454:09
29.46:464:08
39.46:474:08
49.36:484:08
59.36:494:08
69.36:494:08
79.36:504:08
89.36:514:08
99.36:524:08
109.36:534:08
119.26:544:08
129.26:544:08
139.26:554:09
149.26:564:09
159.26:564:09
169.26:574:09
179.26:584:10
189.26:584:10
199.26:594:10
209.26:594:11
219.27:004:11
229.27:004:12
239.27:014:12
249.27:014:13
259.27:024:13
269.27:024:14
279.27:024:14
289.27:034:15
299.27:034:16
309.27:034:16
319.27:034:17

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.73 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.73 kWh/m² to a high of 5.22 kWh/m² in May across the year — December's 1.73 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.8Dim
201.8Dim
211.8Dim
221.8Dim
231.8Dim
241.8Dim
251.8Dim
261.8Dim
271.9Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Is December a good time to visit Semboku?

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

0.0
Sightseeing
10th-best month of the year
0.0
Beach & pool
8th-best month of the year

December is a weaker month for outdoor sightseeing in Semboku.

What to pack for Semboku in December

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

In December, Semboku sees daytime highs around 2°C and nights near -5°C. Pack a warm layer, a heavy coat and rain gear. About 19 days see rain.

a warm layera heavy coatrain gear

UV index in Semboku 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 Semboku peaks around August 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighVery highHighModerateLowAug 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul6High
Aug9Very high
Sep7High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Semboku 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 Semboku is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1420 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May19Moderate
Jun14Moderate
Jul12Moderate
Aug11Good
Sep11Good
Oct12Good
Nov11Good
Dec9Good
Location & terrain

Where is Semboku?

Semboku sits at 39.7°N, 140.7°E, 389 m above sea level, in Japan. The nearest listed city is Shizukuishi, 20 km away.

Topography around Semboku

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

Within 3 km, the terrain around Semboku has large variations in elevation — a maximum elevation change of 836 m around an average of 444 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,556 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,976 m.

The land around Semboku is covered by trees (88%) within 3 km, trees (91%) within 16 km, and trees (80%) within 80 km.

3 km
836 m
16 km
1,556 m
80 km
1,976 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Shizukuishi 20 km · Morioka 35 km · Takizawa 35 km · Yahaba 36 km · Ōmagari 37 km · Rokugō 37 km · Daisen 37 km · Hachimantai 39 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 Semboku (39.7093°, 140.7465°, elevation 389 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. 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).