Kōzan weather in December

In December, Kōzan sees average daytime highs of 11°C and overnight lows near 3°C, with 50 mm of precipitation across 5.9 wet days and about 9.7 hours of daylight. It is the 10th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 13°C in the first days to 10°C by the end. The sky is clear or mostly clear about 30% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 54 min at the start of December to 9 h 42 min by month's end. Set against the rest of the year, December is Kōzan's 3rd-clearest and 4th-windiest month. For the whole year in context, see Kōzan's year-round climate.

Daytime high
11°
10th warmest
Overnight low
3rd coldest
Precipitation
50 mm
5.9 wet days
Daylight
9 h 42 min
7:13 AM – 4:55 PM
Cloud cover
54%
3rd clearest
Wind
10 km/h
4th windiest
Solar energy
2.24 kWh/m²
Travel score
3.0
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 13°C in the first days to 10°C by the end.

A typical December day in Kōzan reaches about 11°C in the afternoon and slips back to 3°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 7°C and 15°C. Set against its neighbours, December runs about 6°C cooler than November and about 2°C warmer than January.

-5°10°15°20°151015202531
Avg high (°C)Avg low (°C)
1135
2135
3134
4134
5134
6124
7124
8124
9124
10123
11113
12113
13113
14113
15113
16113
17113
18113
19103
20102
21102
22102
23102
24102
25102
26102
27102
28102
29102
30102
3192

How December really feels in Kōzan

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 15 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
15
wind chill below the day's low

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

Kōzan weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 435.419.91.8
Feb10° / 547.21.410.72.2
Mar14° / 959.90.411.73.9
Apr19° / 1109.7012.86.0
May23° / 14°1299.9013.86.8
Jun26° / 19°19212.8014.35.8
Jul30° / 23°20713.7014.14.4
Aug32° / 24°12512.2013.33.9
Sep28° / 20°16011012.25.7
Oct22° / 13°1037.6011.17.2
Nov17° / 596.6010.25.7
Dec11° / 505.90.49.73.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 29% of December, with mostly cloudy or overcast conditions the remaining 41%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16040
26040
36040
45941
55941
65941
75842
85941
95842
105842
115842
125743
135842
145743
155743
165743
175743
185743
195842
205842
215941
225941
235941
245941
256040
266040
276040
286040
296139
306040
316040

Chance of precipitation in December

Any precipitationSnow

Kōzan gets around 50 mm of rain and snow over 5.9 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 18% and peaks near 22% on the wettest days, and about 0 day brings snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
1221
2221
3221
4221
5211
6211
7211
8201
9201
10191
11191
12180
13180
14180
15180
16180
17170
18171
19171
20171
21171
22171
23171
24172
25172
26172
27172
28172
29162
30162
31162

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 (%)Comfortable (%)
1982
2991
3991
4991
5991
6991
7991
8991
9991
10991
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

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
149calm
159calm
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 54 min at the start of December to 9 h 42 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 7:02 AM to 7:20 AM, and sunset from 4:53 PM to 5:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.97:024:53
29.87:034:53
39.87:044:53
49.87:044:53
59.87:054:53
69.87:064:53
79.87:074:53
89.87:084:53
99.77:084:53
109.77:094:53
119.77:104:54
129.77:114:54
139.77:114:54
149.77:124:54
159.77:124:55
169.77:134:55
179.77:144:55
189.77:144:56
199.77:154:56
209.77:154:56
219.77:164:57
229.77:164:57
239.77:174:58
249.77:174:58
259.77:184:59
269.77:184:59
279.77:185:00
289.77:195:00
299.77:195:01
309.77:195:02
319.77:205:02

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.24 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.24 kWh/m² to a high of 5.56 kWh/m² in May across the year — December's 2.24 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.4Moderate
22.3Moderate
32.3Moderate
42.3Moderate
52.3Moderate
62.3Moderate
72.3Moderate
82.3Moderate
92.3Moderate
102.2Moderate
112.2Moderate
122.2Moderate
132.2Moderate
142.2Moderate
152.2Moderate
162.2Moderate
172.2Moderate
182.2Moderate
192.2Moderate
202.2Moderate
212.2Moderate
222.2Moderate
232.3Moderate
242.3Moderate
252.3Moderate
262.3Moderate
272.3Moderate
282.3Moderate
292.3Moderate
302.3Moderate
312.4Moderate
Planning a trip in December

Hazard calendar for Kōzan

In seasonPeak

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

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

Kōzan's rainy season runs March–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 Kōzan?

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

3.0
Sightseeing
10th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Kōzan.

What to pack for Kōzan in December

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

In December, Kōzan sees daytime highs around 11°C and nights near 3°C. Pack a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Kōzan in December

The nearest coast averages about 16°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 38 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 3 to Nov 12 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul25Warm
Aug27Warm
Sep27Warm
Oct23Refreshing
Nov20Cool
Dec16Cool

UV index in Kōzan in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Kōzan peaks around July 15 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJul 15UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Kōzan 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 Kōzan is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1322 µg/m³Oct 1711 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb17Moderate
Mar21Moderate
Apr22Moderate
May20Moderate
Jun18Moderate
Jul14Moderate
Aug14Moderate
Sep12Good
Oct11Good
Nov12Good
Dec11Good
Location & terrain

Where is Kōzan?

Kōzan sits at 34.6°N, 133.1°E, 337 m above sea level, in Japan. The nearest listed city is Fuchūchō, 17 km away.

Topography around Kōzan

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

Within 3 km, the terrain around Kōzan has significant variations in elevation — a maximum elevation change of 315 m around an average of 432 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 710 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,264 m.

The land around Kōzan is covered by trees (72%) within 3 km, trees (85%) within 16 km, and trees (68%) and water (22%) within 80 km.

3 km
315 m
16 km
710 m
80 km
1,264 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Fuchūchō 17 km · Mihara 21 km · Shin’ichi 21 km · Onomichi 23 km · Shōbara 30 km · Takehara 30 km · Miyoshi 30 km · Fukuyama 31 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 Kōzan (34.5833°, 133.05°, elevation 337 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).