Aki weather in December

In December, Aki sees average daytime highs of 12°C and overnight lows near 6°C, with 87 mm of rain across 6.1 wet days and about 9.8 hours of daylight. It is the 10th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 14°C in the first days to 10°C by the end. The sky is clear or mostly clear about 53% 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 48 min by month's end. Set against the rest of the year, December is Aki's 1st-clearest and 4th-windiest month. For the whole year in context, see Aki's year-round climate.

Daytime high
12°
10th warmest
Overnight low
3rd coldest
Rainfall
87 mm
6.1 wet days
Daylight
9 h 48 min
7:07 AM – 4:54 PM
Cloud cover
42%
1st clearest
Wind
12 km/h
4th windiest
Solar energy
2.64 kWh/m²
Travel score
3.6
out of 10

Aki is city in Kōchi Prefecture, Japan.

Density
52/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 14°C in the first days to 10°C by the end.

A typical December day in Aki reaches about 12°C in the afternoon and slips back to 6°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 15°C. Set against its neighbours, December runs about 5°C cooler than November and about 2°C warmer than January.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1148
2148
3148
4148
5138
6137
7137
8137
9137
10137
11127
12127
13126
14126
15126
16126
17126
18116
19116
20116
21116
22115
23115
24115
25115
26115
27115
28115
29105
30105
31105

How December really feels in Aki

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

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Aki 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
Jan10° / 776.40.5102.3
Feb10° / 1017.80.910.82.5
Mar13° / 16711.20.111.73.8
Apr18° / 11°20311.6012.85.4
May21° / 16°23612.7013.76.0
Jun24° / 20°35819.1014.25.1
Jul27° / 23°35320.30144.7
Aug28° / 24°26119.6013.24.6
Sep26° / 21°30216.9012.25.5
Oct22° / 16°21711.3011.26.6
Nov17° / 11°1188.1010.35.8
Dec12° / 876.109.83.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 53% of the time in December, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 30%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16535
26535
36634
46634
56733
66832
76832
86931
96931
106931
116931
126931
137030
146931
156931
166931
176931
186931
196931
206931
217129
227129
237129
247228
257327
267426
277426
287426
297426
307426
317426

Chance of precipitation in December

Any precipitation

Aki gets around 87 mm of rain over 6.1 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 20% and peaks near 26% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
126
225
325
424
524
623
723
822
922
1021
1121
1220
1320
1419
1519
1619
1718
1818
1918
2018
2118
2217
2317
2417
2517
2617
2717
2816
2916
3016
3116

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19541
29541
39541
49631
59631
69631
79730
89820
99820
109820
119820
129820
139820
149910
159910
169910
179910
189910
199910
209910
219910
229910
239910
249910
259910
2610000
2710000
2810000
2910000
3010000
3110000

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 12 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
1511calm
1611calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012calm
3112calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 54 min at the start of December to 9 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:56 AM to 7:13 AM, and sunset from 4:52 PM to 5:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.96:564:52
29.96:574:52
39.96:584:52
49.96:584:52
59.96:594:52
69.97:004:52
79.97:014:52
89.97:014:52
99.87:024:53
109.87:034:53
119.87:044:53
129.87:044:53
139.87:054:53
149.87:064:54
159.87:064:54
169.87:074:54
179.87:074:55
189.87:084:55
199.87:094:55
209.87:094:56
219.87:104:56
229.87:104:57
239.87:114:57
249.87:114:58
259.87:114:58
269.87:124:59
279.87:124:59
289.87:125:00
299.87:135:00
309.87:135:01
319.87:135:02

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.64 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.64 kWh/m² to a high of 5.62 kWh/m² in May across the year — December's 2.64 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.7Moderate
22.7Moderate
32.6Moderate
42.6Moderate
52.6Moderate
62.6Moderate
72.6Moderate
82.6Moderate
92.6Moderate
102.6Moderate
112.6Moderate
122.6Moderate
132.6Moderate
142.6Moderate
152.6Moderate
162.6Moderate
172.6Moderate
182.6Moderate
192.6Moderate
202.7Moderate
212.7Moderate
222.7Moderate
232.7Moderate
242.7Moderate
252.7Moderate
262.7Moderate
272.8Moderate
282.8Moderate
292.8Moderate
302.8Moderate
312.8Moderate
Planning a trip in December

Hazard calendar for Aki

In seasonPeak

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

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

Aki'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 Aki?

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

3.6
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 Aki.

What to pack for Aki in December

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

In December, Aki sees daytime highs around 12°C and nights near 6°C. Pack a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Aki in December

The nearest coast averages about 20°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 14 km away) is warmest in August at about 28°C and coldest in February near 17°C.

It's comfortable for a long swim from May 3 to Dec 19 — about 7.6 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan18Cool
Feb17Cool
Mar18Cool
Apr19Cool
May21Refreshing
Jun23Refreshing
Jul26Warm
Aug28Warm
Sep27Warm
Oct25Warm
Nov23Refreshing
Dec20Refreshing

UV index in Aki 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 Aki peaks around June 23 at about 11 (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 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJun 23UV 11Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr8Very high
May9Very high
Jun11Extreme
Jul11Extreme
Aug9Very high
Sep10Very high
Oct7High
Nov4Moderate
Dec3Moderate

Air quality in Aki 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 Aki is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (September, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1320 µg/m³Sep 2010 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar19Moderate
Apr20Moderate
May18Moderate
Jun15Moderate
Jul11Good
Aug11Good
Sep10Good
Oct10Good
Nov11Good
Dec11Good
Location & terrain

Where is Aki?

Aki sits at 33.5°N, 133.9°E, 13 m above sea level, in Japan. The nearest listed city is Yamashita, 20 km away.

Topography around Aki

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

Within 3 km, the terrain around Aki has significant variations in elevation — a maximum elevation change of 426 m around an average of 37 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,031 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,939 m.

The land around Aki is covered by water (45%) and trees (23%) within 3 km, trees (53%) and water (42%) within 16 km, and trees (54%) and water (41%) within 80 km.

3 km
426 m
16 km
1,031 m
80 km
1,939 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Yamashita 20 km · Tosayamadachō-nakano 23 km · Nankoku 24 km · Muroto-misakicho 34 km · Kochi 34 km · Tosa 42 km · Ino 44 km · Susaki 58 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 Aki (33.5°, 133.9°, elevation 13 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).