Ōshū weather in December

In December, Ōshū sees average daytime highs of 4°C and overnight lows near -3°C, with 68 mm of precipitation across 12.4 wet days and about 9.3 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 6°C in the first days to 2°C by the end. The sky is clear or mostly clear about 15% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 30 min at the start of December to 9 h 18 min by month's end. Set against the rest of the year, December is Ōshū's 5th-clearest and 5th-windiest month. For the whole year in context, see Ōshū's year-round climate.

Daytime high
10th warmest
Overnight low
-3°
3rd coldest
Precipitation
68 mm
12.4 wet days
Daylight
9 h 18 min
6:54 AM – 4:09 PM
Cloud cover
66%
5th clearest
Wind
10 km/h
5th windiest
Solar energy
1.98 kWh/m²
Travel score
0.1
out of 10

Ōshū is city in Iwate Prefecture, Japan.

Density
114/km²
people per km²
Founded
2006

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 6°C in the first days to 2°C by the end.

A typical December day in Ōshū reaches about 4°C in the afternoon and slips back to -3°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between -0°C and 8°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-10°10°151015202531
Avg high (°C)Avg low (°C)
16-1
26-1
36-1
46-1
56-1
65-1
75-2
85-2
95-2
105-2
114-2
124-2
134-3
144-3
154-3
164-3
173-3
183-3
193-3
203-4
213-4
223-4
233-4
243-4
252-4
262-4
272-4
282-5
292-5
302-5
312-5

How December really feels in Ōshū

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.

Ōshū 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 / -7°5810.7129.60.0
Feb / -7°5310.19.710.50.0
Mar / -3°9213.28.211.70.6
Apr13° / 9813.42.2133.3
May18° / 11012.5014.15.4
Jun21° / 14°12312.9014.75.7
Jul25° / 18°16616.5014.55.5
Aug26° / 19°15315.2013.55.6
Sep22° / 15°15113.5012.35.8
Oct17° / 12011.20115.0
Nov10° / 7311.72.29.92.2
Dec / -3°6812.48.89.30.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 26% of December, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24258
34357
44357
54258
64159
74159
84159
94159
104159
114159
124060
134060
144060
154060
164060
174060
183961
193961
203961
214060
224060
233961
244060
254060
264060
274060
284060
294060
304060
314159

Chance of precipitation in December

Any precipitationSnow

Ōshū gets around 68 mm of rain and snow over 12.4 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 40% and peaks near 41% on the wettest days, and about 9 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
14117
24117
34118
44119
54120
64121
74122
84123
94124
104124
114125
124026
134027
144028
154029
164029
174030
184031
193931
203932
213932
223933
233934
243934
253934
263935
273935
283836
293836
303837
313837

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 10 km/h in December.

Across December, daily wind ranges from about 9 km/h on the calmest days to 10 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
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 30 min at the start of December to 9 h 18 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 6:42 AM to 7:00 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)
19.56:424:09
29.46:434:08
39.46:434:08
49.46:444:08
59.46:454:08
69.46:464:08
79.46:474:08
89.36:484:08
99.36:494:08
109.36:494:08
119.36:504:08
129.36:514:08
139.36:524:09
149.36:524:09
159.36:534:09
169.36:544:09
179.36:544:10
189.36:554:10
199.26:554:10
209.26:564:11
219.26:564:11
229.26:574:12
239.26:574:12
249.26:584:13
259.26:584:13
269.36:594:14
279.36:594:14
289.36:594:15
299.37:004:16
309.37:004:16
319.37:004:17

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.98 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.98 kWh/m² to a high of 5.24 kWh/m² in May across the year — December's 1.98 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.0Moderate
22.0Moderate
32.0Moderate
42.0Dim
52.0Dim
62.0Dim
72.0Dim
81.9Dim
91.9Dim
101.9Dim
111.9Dim
121.9Dim
131.9Dim
142.0Dim
152.0Dim
162.0Dim
172.0Dim
182.0Dim
192.0Moderate
202.0Moderate
212.0Moderate
222.0Moderate
232.1Moderate
242.1Moderate
252.1Moderate
262.1Moderate
272.1Moderate
282.1Moderate
292.2Moderate
302.2Moderate
312.2Moderate
Planning a trip in December

Hazard calendar for Ōshū

In seasonPeak

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

Ōshū 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 Ōshū?

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

0.1
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 Ōshū.

What to pack for Ōshū in December

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

In December, Ōshū sees daytime highs around 4°C and nights near -3°C. Pack a warm layer. Worth having: a heavy coat and rain gear. About 12 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Ōshū in December

The nearest coast averages about 13°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 49 km away) is warmest in August at about 22°C and coldest in March near 7°C.

It's comfortable for a long swim from Jul 21 to Oct 3 — about 2.5 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan11Bracing
Feb8Bracing
Mar7Bracing
Apr9Bracing
May12Bracing
Jun17Cool
Jul20Cool
Aug22Refreshing
Sep22Refreshing
Oct19Cool
Nov16Cool
Dec13Bracing

UV index in Ōshū 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 Ōshū peaks around August 19 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighVery highHighModerateLowAug 19UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul6High
Aug9Very high
Sep7Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Ōshū 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 Ōshū is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1620 µg/m³Dec 1710 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May19Moderate
Jun14Moderate
Jul12Moderate
Aug11Good
Sep11Good
Oct11Good
Nov11Good
Dec9Good
Location & terrain

Where is Ōshū?

Ōshū sits at 39.1°N, 141.2°E, 36 m above sea level, in Japan. The nearest listed city is Mizusawa, 3.0 km away.

Topography around Ōshū

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

Within 3 km, the terrain around Ōshū has only modest variations in elevation — a maximum elevation change of 104 m around an average of 45 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 767 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,007 m.

The land around Ōshū is covered by artificial surfaces (38%), cropland (32%) and trees (23%) within 3 km, trees (59%) and cropland (30%) within 16 km, and trees (71%) within 80 km.

3 km
104 m
16 km
767 m
80 km
2,007 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Mizusawa 3.0 km · Kanegasaki 8.0 km · Kitakami 17 km · Ichinoseki 25 km · Hanamaki 27 km · Tōno 37 km · Rikuzen-Takata 44 km · Kesennuma 44 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 Ōshū (39.1393°, 141.1685°, elevation 36 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).