Sennan weather in December

In December, Sennan sees average daytime highs of 12°C and overnight lows near 6°C, with 86 mm of precipitation across 10.7 wet days and about 9.7 hours of daylight. It is the 10th-warmest and 10th-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 33% 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 Sennan's 3rd-clearest and 4th-windiest month. For the whole year in context, see Sennan's year-round climate.

Daytime high
12°
10th warmest
Overnight low
3rd coldest
Precipitation
86 mm
10.7 wet days
Daylight
9 h 42 min
7:04 AM – 4:47 PM
Cloud cover
52%
3rd clearest
Wind
14 km/h
4th windiest
Solar energy
2.43 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 Sennan 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 3°C warmer than January.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1148
2148
3148
4137
5137
6137
7137
8137
9127
10127
11126
12126
13126
14126
15116
16116
17116
18116
19115
20115
21115
22115
23115
24115
25105
26105
27105
28105
29105
30105
31104

How December really feels in Sennan

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.

Sennan 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 / 8211.41.6101.8
Feb10° / 8510.71.710.72.1
Mar13° / 12512.50.211.73.5
Apr18° / 11°12611012.85.6
May22° / 15°14910.7013.86.5
Jun25° / 20°23214.1014.35.8
Jul29° / 24°19513.5014.15.1
Aug30° / 25°11411.4013.34.7
Sep27° / 22°18213012.25.8
Oct22° / 16°17910.9011.16.7
Nov17° / 11°1008.8010.25.5
Dec12° / 8610.70.89.73.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% 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 40%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15941
25842
35842
45842
55941
65842
75842
85941
95842
105842
115842
125842
135842
145842
155842
165941
175941
186040
196040
206040
216139
226139
236238
246238
256238
266238
276238
286238
296337
306238
316139

Chance of precipitation in December

Any precipitationSnow

Sennan gets around 86 mm of rain and snow over 10.7 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 33% and peaks near 37% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1300
2300
3300
4300
5300
6300
7310
8310
9311
10321
11321
12321
13331
14331
15332
16342
17342
18352
19353
20353
21363
22364
23364
24374
25374
26374
27364
28364
29364
30354
31354

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19721
29721
39721
49721
59721
69820
79820
89910
99910
109910
119910
129910
139910
149910
159910
1610000
1710000
1810000
1910000
2010000
2110000
2210000
2310000
2410000
2510000
2610000
2710000
2810000
2910000
3010000
3110000

Wind in December

Winds average 14 km/h in December.

Across December, daily wind ranges from about 13 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

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 6:53 AM to 7:10 AM, and sunset from 4:45 PM to 4:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.96:534:45
29.96:534:45
39.86:544:45
49.86:554:45
59.86:564:45
69.86:574:45
79.86:574:45
89.86:584:45
99.86:594:45
109.87:004:45
119.77:004:45
129.77:014:45
139.77:024:46
149.77:024:46
159.77:034:46
169.77:044:47
179.77:044:47
189.77:054:47
199.77:054:48
209.77:064:48
219.77:064:48
229.77:074:49
239.77:074:49
249.77:084:50
259.77:084:50
269.77:094:51
279.77:094:52
289.77:094:52
299.77:104:53
309.77:104:53
319.77:104:54

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.43 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.43 kWh/m² to a high of 5.56 kWh/m² in May across the year — December's 2.43 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.5Moderate
22.5Moderate
32.5Moderate
42.5Moderate
52.5Moderate
62.5Moderate
72.5Moderate
82.4Moderate
92.4Moderate
102.4Moderate
112.4Moderate
122.4Moderate
132.4Moderate
142.4Moderate
152.4Moderate
162.4Moderate
172.4Moderate
182.4Moderate
192.4Moderate
202.4Moderate
212.5Moderate
222.5Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.6Moderate
Planning a trip in December

Hazard calendar for Sennan

In seasonPeak

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

Sennan 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 Sennan?

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 Sennan.

What to pack for Sennan in December

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

In December, Sennan sees daytime highs around 12°C and nights near 6°C. Pack a warm layer. Worth having: rain gear. About 11 days see rain.

a warm layerrain gear

Sea temperature near Sennan in December

The nearest coast averages about 17°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 13 km away) is warmest in August at about 27°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 3 to Nov 16 — about 5.5 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr16Cool
May18Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov20Refreshing
Dec17Cool

UV index in Sennan 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 Sennan peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highModerateJun 23UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun10Very high
Jul10Very high
Aug7High
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Sennan 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 Sennan is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1625 µg/m³Oct 1914 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb19Moderate
Mar24Moderate
Apr26Moderate
May24Moderate
Jun21Moderate
Jul22Moderate
Aug24Moderate
Sep17Moderate
Oct14Moderate
Nov16Moderate
Dec15Moderate
Location & terrain

Where is Sennan?

Sennan sits at 34.3°N, 135.3°E, 29 m above sea level, in Japan. The nearest listed city is Hannan, 2.0 km away.

Topography around Sennan

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

Within 3 km, the terrain around Sennan has significant variations in elevation — a maximum elevation change of 320 m around an average of 71 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 868 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,879 m.

The land around Sennan is covered by trees (46%) and artificial surfaces (41%) within 3 km, trees (38%), water (34%) and artificial surfaces (20%) within 16 km, and trees (49%) and water (33%) within 80 km.

3 km
320 m
16 km
868 m
80 km
1,879 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Hannan 2.0 km · Izumisano 9.0 km · Ōkubo-naka 9.0 km · Iwade 12 km · Kaizuka 14 km · Kinokawa 16 km · Wakayama 16 km · Kishiwada 16 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 Sennan (34.3484°, 135.2684°, elevation 29 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).