Shiraoi weather in December

In December, Shiraoi sees average daytime highs of 1°C and overnight lows near -5°C, with 64 mm of precipitation across 8.8 wet days and about 8.9 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 2°C in the first days to -1°C by the end. The sky is clear or mostly clear about 22% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 06 min at the start of December to 8 h 54 min by month's end. Set against the rest of the year, December is Shiraoi's 4th-clearest and 1st-windiest month. For the whole year in context, see Shiraoi's year-round climate.

Daytime high
10th warmest
Overnight low
-5°
3rd coldest
Precipitation
64 mm
8.8 wet days
Daylight
8 h 54 min
7:04 AM – 3:58 PM
Cloud cover
61%
4th clearest
Wind
17 km/h
1st windiest
Solar energy
1.74 kWh/m²
Travel score
0.0
out of 10

Shiraoi is town in Shiraoi district, Hokkaidō, Japan.

Density
42/km²
people per km²
Founded
1954

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 2°C in the first days to -1°C by the end.

A typical December day in Shiraoi reaches about 1°C in the afternoon and slips back to -5°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 5°C. Set against its neighbours, December runs about 6°C cooler than November and about 2°C warmer than January.

-10°-5°10°151015202531
Avg high (°C)Avg low (°C)
13-2
23-2
32-2
42-3
52-3
62-3
72-3
81-3
91-4
101-4
111-4
121-4
131-4
141-5
150-5
160-5
170-5
180-5
190-5
200-5
210-5
220-5
230-6
240-6
250-6
26-1-6
27-1-6
28-1-6
29-1-6
30-1-6
31-1-6

How December really feels in Shiraoi

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
20 feel bitter (≤ -10°C)

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

Shiraoi 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-2° / -7°477.18.29.20.0
Feb-1° / -7°456.97.710.30.0
Mar / -4°649.88.711.60.0
Apr / 8210.83.113.10.9
May12° / 11312.20.114.43.0
Jun16° / 12°9810.6015.14.7
Jul20° / 16°14313.3014.85.5
Aug22° / 18°19413.9013.75.8
Sep20° / 15°17713.5012.35.6
Oct14° / 11411.10.110.84.0
Nov / 8410.42.89.60.9
Dec / -5°648.88.68.90.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 27% of December, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24555
34555
44654
54654
64753
74753
84951
94951
105050
115149
125149
135347
145248
155248
165248
175248
185248
195248
205248
215149
225149
235050
244951
254951
264951
274852
284852
294852
304852
314753

Chance of precipitation in December

Any precipitationSnow

Shiraoi gets around 64 mm of rain and snow over 8.8 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 29% and peaks near 31% on the wettest days, and about 9 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
13120
23121
33022
43022
52923
62924
72924
82825
92825
102826
112826
122826
132826
142826
152827
162827
172827
182828
192828
202829
212929
222930
232931
242931
252931
262932
272932
282832
292832
302732
312731

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 17 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 17 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
517light breeze
617light breeze
717light breeze
817light breeze
917light breeze
1017light breeze
1117light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze
3117light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 06 min at the start of December to 8 h 54 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 6:51 AM to 7:10 AM, and sunset from 3:58 PM to 4:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.16:513:58
29.16:523:57
39.16:533:57
49.06:543:57
59.06:553:57
69.06:563:57
79.06:573:57
89.06:583:57
99.06:593:57
109.07:003:57
118.97:003:57
128.97:013:57
138.97:023:57
148.97:033:57
158.97:033:57
168.97:043:58
178.97:053:58
188.97:053:58
198.97:063:58
208.97:063:59
218.97:073:59
228.97:074:00
238.97:084:00
248.97:084:01
258.97:094:01
268.97:094:02
278.97:094:03
288.97:104:03
298.97:104:04
308.97:104:05
318.97:104:05

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.74 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.74 kWh/m² to a high of 5.48 kWh/m² in May across the year — December's 1.74 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.8Dim
71.8Dim
81.8Dim
91.8Dim
101.8Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.8Dim
171.8Dim
181.8Dim
191.8Dim
201.8Dim
211.8Dim
221.8Dim
231.8Dim
241.8Dim
251.8Dim
261.8Dim
271.8Dim
281.9Dim
291.9Dim
301.9Dim
311.9Dim
Planning a trip in December

Hazard calendar for Shiraoi

In seasonPeak

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

Shiraoi sits in the Pacific typhoon belt; the season peaks July–October.

Shiraoi's rainy season runs May–October, when most of the year's rain falls.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Shiraoi?

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

0.0
Sightseeing
9th-best month of the year
0.0
Beach & pool
7th-best month of the year

December is a weaker month for outdoor sightseeing in Shiraoi.

What to pack for Shiraoi in December

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

In December, Shiraoi sees daytime highs around 1°C and nights near -5°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Shiraoi in December

The nearest coast averages about 10°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 20 km away) is warmest in August at about 20°C and coldest in March near 4°C.

It's comfortable for a long swim from Aug 17 to Aug 28 — about 0.4 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan6Bracing
Feb4Bracing
Mar4Bracing
Apr5Bracing
May8Bracing
Jun13Bracing
Jul17Cool
Aug20Refreshing
Sep20Cool
Oct16Cool
Nov13Bracing
Dec10Bracing

UV index in Shiraoi in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Shiraoi peaks around August 18 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighVery highHighModerateLowAug 18UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr6High
May8Very high
Jun6High
Jul5Moderate
Aug9Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Shiraoi 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 Shiraoi is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1219 µg/m³Dec 158 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May18Moderate
Jun12Moderate
Jul11Good
Aug10Good
Sep9Good
Oct11Good
Nov9Good
Dec8Good
Location & terrain

Where is Shiraoi?

Shiraoi sits at 42.5°N, 141.3°E, 5 m above sea level, in Japan. The nearest listed city is Noboribetsu, 18 km away.

Topography around Shiraoi

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

Within 3 km, the terrain around Shiraoi has only modest variations in elevation — a maximum elevation change of 114 m around an average of 14 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,028 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,858 m.

The land around Shiraoi is covered by water (38%) and trees (35%) within 3 km, trees (47%) and water (46%) within 16 km, and trees (44%) and water (41%) within 80 km.

3 km
114 m
16 km
1,028 m
80 km
1,858 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Noboribetsu 18 km · Tomakomai 23 km · Chitose 39 km · Muroran 39 km · Date 41 km · Eniwa 42 km · Kitahiroshima 51 km · Sapporo 57 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 Shiraoi (42.55°, 141.35°, elevation 5 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).