Shonai weather in December

In December, Shonai sees average daytime highs of 5°C and overnight lows near 0°C, with 206 mm of precipitation across 25.1 wet days and about 9.3 hours of daylight. It is the 10th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 7°C in the first days to 3°C by the end. The sky is clear or mostly clear about 5% 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 Shonai's 11th-clearest and 3rd-windiest month. For the whole year in context, see Shonai's year-round climate.

Daytime high
10th warmest
Overnight low
4th coldest
Precipitation
206 mm
25.1 wet days
Daylight
9 h 18 min
6:58 AM – 4:15 PM
Cloud cover
78%
11th clearest
Wind
12 km/h
3rd windiest
Solar energy
1.62 kWh/m²
Travel score
0.2
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 7°C in the first days to 3°C by the end.

A typical December day in Shonai reaches about 5°C in the afternoon and slips back to 0°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 1°C and 9°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-5°10°15°151015202531
Avg high (°C)Avg low (°C)
182
272
372
472
572
671
761
861
961
1061
1161
1251
1350
1450
1550
1650
1750
1840
1940
2040
2140
2240
2340
244-1
254-1
264-1
274-1
283-1
293-1
303-1
313-1

How December really feels in Shonai

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.

Shonai 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 / -2°19026.224.99.60.0
Feb / -2°13521.719.710.50.0
Mar / 14320.313.711.70.5
Apr13° / 11815.12.8133.1
May19° / 11°12513.6014.15.5
Jun23° / 16°14413.5014.75.9
Jul26° / 20°24718.2014.45.3
Aug27° / 21°20017.3013.55.3
Sep24° / 17°17015.8012.35.6
Oct18° / 11°17516.50114.8
Nov11° / 17319.54.59.92.2
Dec / 20625.118.19.30.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 5% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 11% of December, with mostly cloudy or overcast conditions the remaining 85%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12080
21981
31882
41882
51684
61684
71585
81585
91486
101486
111486
121585
131585
141486
151486
161585
171585
181585
191585
201585
211684
221684
231684
241684
251684
261585
271486
281486
291486
301486
311486

Chance of precipitation in December

Any precipitationSnow

Shonai gets around 206 mm of rain and snow over 25.1 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 81% 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 (%)
17437
27539
37641
47743
57846
67948
78050
88151
98253
108255
118356
128357
138358
148359
158359
168360
178360
188261
198262
208262
218263
228163
238164
248165
258166
268267
278268
288269
298371
308372
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 12 km/h in December.

Across December, daily wind ranges from about 11 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

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 6:46 AM to 7:04 AM, and sunset from 4:14 PM to 4:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.56:464:14
29.56:474:14
39.46:484:14
49.46:494:14
59.46:494:14
69.46:504:14
79.46:514:14
89.46:524:14
99.46:534:14
109.36:544:14
119.36:544:14
129.36:554:14
139.36:564:15
149.36:564:15
159.36:574:15
169.36:584:15
179.36:584:16
189.36:594:16
199.37:004:16
209.37:004:17
219.37:014:17
229.37:014:18
239.37:024:18
249.37:024:19
259.37:024:19
269.37:034:20
279.37:034:20
289.37:034:21
299.37:044:22
309.37:044:22
319.37:044:23

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.62 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.62 kWh/m² to a high of 5.36 kWh/m² in May across the year — December's 1.62 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.7Dim
21.7Dim
31.6Dim
41.6Dim
51.6Dim
61.6Dim
71.6Dim
81.6Dim
91.6Dim
101.6Dim
111.6Dim
121.6Dim
131.6Dim
141.6Dim
151.6Dim
161.6Dim
171.6Dim
181.6Dim
191.6Dim
201.6Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.8Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Hazard calendar for Shonai

In seasonPeak

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

Shonai 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 Shonai?

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 Shonai.

What to pack for Shonai in December

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

In December, Shonai sees daytime highs around 5°C and nights near 0°C. Pack a warm layer and rain gear. Worth having: a heavy coat. About 25 days see rain.

a warm layerrain geara heavy coat

Sea temperature near Shonai 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 24 km away) is warmest in August at about 26°C and coldest in March near 9°C.

It's comfortable for a long swim from Jun 25 to Oct 26 — about 4.1 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb10Bracing
Mar9Bracing
Apr10Bracing
May14Bracing
Jun19Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct21Refreshing
Nov18Cool
Dec15Bracing

UV index in Shonai 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 Shonai peaks around August 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highHighModerateLowAug 17UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul7High
Aug9Very high
Sep7Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Shonai 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 Shonai is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1721 µg/m³Dec 159 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun15Moderate
Jul13Moderate
Aug11Good
Sep10Good
Oct10Good
Nov10Good
Dec9Good
Location & terrain

Where is Shonai?

Shonai sits at 38.8°N, 139.9°E, 7 m above sea level, in Japan. The nearest listed city is Sakata, 9.0 km away.

Topography around Shonai

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

Within 3 km, the terrain around Shonai has only modest variations in elevation — a maximum elevation change of 14 m around an average of 8 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 776 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,205 m.

The land around Shonai is covered by cropland (77%) within 3 km, cropland (37%) and trees (36%) within 16 km, and trees (55%) and water (35%) within 80 km.

3 km
14 m
16 km
776 m
80 km
2,205 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Sakata 9.0 km · Tsuruoka 16 km · Shinjō 36 km · Nikaho 47 km · Obanazawa 51 km · Yachi 59 km · Murayama 61 km · Yurihonjō 62 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 Shonai (38.8485°, 139.9031°, elevation 7 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).