Asahi weather in December

In December, Asahi sees average daytime highs of 12°C and overnight lows near 8°C, with 91 mm of rain across 10 wet days and about 9.6 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 14°C in the first days to 11°C by the end. The sky is clear or mostly clear about 52% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 48 min at the start of December to 9 h 36 min by month's end. Set against the rest of the year, December is Asahi's 2nd-clearest and 6th-windiest month. For the whole year in context, see Asahi's year-round climate.

Daytime high
12°
10th warmest
Overnight low
4th coldest
Rainfall
91 mm
10 wet days
Daylight
9 h 36 min
6:46 AM – 4:21 PM
Cloud cover
44%
2nd clearest
Wind
18 km/h
6th windiest
Solar energy
2.28 kWh/m²
Travel score
3.4
out of 10

Asahi is city in Chiba Prefecture, Japan.

Density
496/km²
people per km²
Founded
2005

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 11°C by the end.

A typical December day in Asahi reaches about 12°C in the afternoon and slips back to 8°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 9°C and 15°C. Set against its neighbours, December runs about 5°C cooler than November and about 3°C warmer than January.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
11410
21410
31410
41410
51410
61310
7139
8139
9139
10139
11139
12139
13128
14128
15128
16128
17128
18128
19128
20127
21117
22117
23117
24117
25117
26117
27117
28117
29116
30106
31106

Asahi 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 daysDaylight (hours)Travel score
Jan10° / 949.39.92.2
Feb10° / 879.610.62.2
Mar12° / 14213.711.73.1
Apr16° / 12°11912.612.94.8
May20° / 16°13411.913.95.9
Jun23° / 20°16512.914.45.9
Jul26° / 23°1331214.26.2
Aug28° / 24°889.913.46.3
Sep25° / 22°17013.112.26.1
Oct21° / 18°22613.911.15.9
Nov17° / 13°12211.810.15.1
Dec12° / 91109.63.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 35%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25743
35743
45842
55842
65941
76040
86139
96238
106238
116337
126337
136436
146436
156436
166535
176535
186634
196634
206733
216733
226832
236832
246931
256931
266931
277030
287030
297129
307228
317228

Chance of precipitation in December

Any precipitation

Asahi gets around 91 mm of rain over 10 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 32% and peaks near 40% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
240
340
440
539
639
738
838
937
1036
1136
1235
1334
1433
1532
1631
1730
1829
1928
2028
2127
2227
2326
2426
2525
2625
2725
2825
2924
3025
3125

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 (%)
19451
29541
39541
49541
59541
69631
79631
89631
99820
109820
119820
129820
139910
149910
159910
169910
179910
1810000
1910000
2010000
2110000
2210000
2310000
2410000
2510000
2610000
2710000
2810000
2910000
3010000
3110000

Wind in December

Winds average 18 km/h in December.

Across December, daily wind ranges from about 18 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2018light breeze
2118light breeze
2218light breeze
2318light breeze
2418light breeze
2518light breeze
2618light breeze
2718light breeze
2818light breeze
2918light breeze
3018light breeze
3118light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 48 min at the start of December to 9 h 36 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 6:34 AM to 6:52 AM, and sunset from 4:20 PM to 4:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.86:344:20
29.76:354:20
39.76:364:20
49.76:374:20
59.76:384:20
69.76:394:20
79.76:394:20
89.76:404:20
99.66:414:20
109.66:424:20
119.66:424:20
129.66:434:20
139.66:444:21
149.66:454:21
159.66:454:21
169.66:464:21
179.66:464:22
189.66:474:22
199.66:484:22
209.66:484:23
219.66:494:23
229.66:494:24
239.66:494:24
249.66:504:25
259.66:504:25
269.66:514:26
279.66:514:26
289.66:514:27
299.66:524:28
309.66:524:28
319.66:524:29

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.28 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.28 kWh/m² to a high of 5.54 kWh/m² in May across the year — December's 2.28 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.2Moderate
22.2Moderate
32.2Moderate
42.2Moderate
52.2Moderate
62.2Moderate
72.2Moderate
82.2Moderate
92.2Moderate
102.2Moderate
112.2Moderate
122.3Moderate
132.3Moderate
142.3Moderate
152.3Moderate
162.3Moderate
172.3Moderate
182.3Moderate
192.3Moderate
202.4Moderate
212.4Moderate
222.4Moderate
232.4Moderate
242.4Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.6Moderate
Planning a trip in December

Hazard calendar for Asahi

In seasonPeak

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

Asahi 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 Asahi?

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

3.4
Sightseeing
9th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Asahi.

What to pack for Asahi in December

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

In December, Asahi sees daytime highs around 12°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Asahi in December

The nearest coast averages about 18°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 25°C and coldest in February near 15°C.

It's comfortable for a long swim from Jun 5 to Nov 22 — about 5.6 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Bracing
Mar15Cool
Apr16Cool
May19Cool
Jun21Refreshing
Jul23Refreshing
Aug25Warm
Sep25Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Asahi 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 Asahi peaks around August 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highVery highHighModerateAug 12UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Extreme
Sep8Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Asahi 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 Asahi is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (December, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1920 µg/m³Dec 178 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar18Moderate
Apr20Moderate
May19Moderate
Jun14Moderate
Jul12Good
Aug11Good
Sep10Good
Oct10Good
Nov9Good
Dec7Good
Location & terrain

Where is Asahi?

Asahi sits at 35.7°N, 140.7°E, 5 m above sea level, in Japan. The nearest listed city is Sōsa, 9.0 km away.

Topography around Asahi

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

Within 3 km, the terrain around Asahi has only modest variations in elevation — a maximum elevation change of 19 m around an average of 7 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 71 m; within 80 km, large variations in elevation — a maximum elevation change of 840 m.

The land around Asahi is covered by cropland (41%) and artificial surfaces (39%) within 3 km, water (34%), cropland (27%) and trees (22%) within 16 km, and water (44%) and trees (24%) within 80 km.

3 km
19 m
16 km
71 m
80 km
840 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Sōsa 9.0 km · Yōkaichiba 9.0 km · Omigawa 15 km · Hasaki 17 km · Choshi 17 km · Yokoshiba 17 km · Kamisu 20 km · Sawara 23 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 Asahi (35.7167°, 140.65°, 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).