Sayō weather in December

In December, Sayō sees average daytime highs of 10°C and overnight lows near 2°C, with 51 mm of precipitation across 6 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 12°C in the first days to 9°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 48 min at the start of December to 9 h 42 min by month's end. Set against the rest of the year, December is Sayō's 3rd-clearest and 5th-windiest month. For the whole year in context, see Sayō's year-round climate.

Daytime high
10°
10th warmest
Overnight low
3rd coldest
Precipitation
51 mm
6 wet days
Daylight
9 h 42 min
7:09 AM – 4:48 PM
Cloud cover
54%
3rd clearest
Wind
9 km/h
5th windiest
Solar energy
2.29 kWh/m²
Travel score
2.7
out of 10

Sayō is town in Sayo District, Hyogo Prefecture, Japan.

Density
52/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 12°C in the first days to 9°C by the end.

A typical December day in Sayō reaches about 10°C in the afternoon and slips back to 2°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 14°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-5°10°15°20°151015202531
Avg high (°C)Avg low (°C)
1134
2134
3124
4123
5123
6123
7123
8113
9113
10113
11112
12112
13102
14102
15102
16102
17102
18102
19102
20102
21101
2291
2391
2491
2591
2691
2791
2891
2991
3091
3191

How December really feels in Sayō

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 21 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
21
wind chill below the day's low

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

Sayō 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 / 445.81.69.91.4
Feb / 567.2210.71.8
Mar13° / 11010.80.411.73.4
Apr18° / 12210.4012.95.7
May23° / 13°14510.6013.86.6
Jun26° / 18°18513.5014.35.8
Jul30° / 22°21715.7014.14.4
Aug31° / 23°13413.3013.34.2
Sep27° / 19°18411.8012.25.9
Oct22° / 13°1178011.17.0
Nov16° / 626.1010.25.4
Dec10° / 5160.69.72.7

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 28% of December, with mostly cloudy or overcast conditions the remaining 42%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15941
25941
35941
45941
55842
65941
75842
85842
95842
105842
115743
125743
135743
145743
155743
165644
175743
185644
195644
205743
215743
225842
235842
245941
255842
265842
275941
285941
295941
305941
315941

Chance of precipitation in December

Any precipitationSnow

Sayō gets around 51 mm of rain and snow over 6 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 19% and peaks near 21% on the wettest days, and about 1 day brings snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
1210
2210
3210
4210
5210
6210
7210
8210
9201
10201
11201
12191
13191
14191
15191
16191
17181
18182
19182
20182
21183
22183
23183
24183
25174
26174
27174
28164
29164
30164
31154

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 (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 9 km/h in December.

Across December, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 48 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 6 minutes over December. Sunrise moves from 6:58 AM to 7:15 AM, and sunset from 4:47 PM to 4:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.86:584:47
29.86:594:47
39.87:004:47
49.87:004:47
59.87:014:47
69.77:024:47
79.77:034:47
89.77:034:47
99.77:044:47
109.77:054:47
119.77:064:47
129.77:064:47
139.77:074:48
149.77:084:48
159.77:084:48
169.77:094:48
179.77:104:49
189.67:104:49
199.67:114:50
209.67:114:50
219.67:124:50
229.67:124:51
239.67:134:51
249.67:134:52
259.67:144:52
269.67:144:53
279.77:144:53
289.77:154:54
299.77:154:55
309.77:154:55
319.77:154:56

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.29 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.29 kWh/m² to a high of 5.73 kWh/m² in May across the year — December's 2.29 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.4Moderate
22.4Moderate
32.4Moderate
42.3Moderate
52.3Moderate
62.3Moderate
72.3Moderate
82.3Moderate
92.3Moderate
102.3Moderate
112.3Moderate
122.3Moderate
132.3Moderate
142.3Moderate
152.3Moderate
162.3Moderate
172.3Moderate
182.3Moderate
192.3Moderate
202.3Moderate
212.3Moderate
222.3Moderate
232.3Moderate
242.3Moderate
252.3Moderate
262.4Moderate
272.4Moderate
282.4Moderate
292.4Moderate
302.4Moderate
312.4Moderate
Planning a trip in December

Hazard calendar for Sayō

In seasonPeak

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

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

Sayō'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 Sayō?

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

2.7
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 Sayō.

What to pack for Sayō in December

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

In December, Sayō sees daytime highs around 10°C and nights near 2°C. Pack a warm layer. About 6 days see rain.

a warm layer

Sea temperature near Sayō 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 42 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 7 to Nov 12 — about 5.2 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct24Refreshing
Nov20Cool
Dec16Cool

UV index in Sayō 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 Sayō peaks around July 15 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 23UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May9Very high
Jun10Very high
Jul11Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec3Moderate

Air quality in Sayō 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 Sayō is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1421 µg/m³Oct 1711 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb16Moderate
Mar20Moderate
Apr21Moderate
May19Moderate
Jun17Moderate
Jul14Moderate
Aug12Moderate
Sep12Good
Oct10Good
Nov12Good
Dec11Good
Location & terrain

Where is Sayō?

Sayō sits at 35.0°N, 134.4°E, 155 m above sea level, in Japan. The nearest listed city is Kamigōri, 14 km away.

Topography around Sayō

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

Within 3 km, the terrain around Sayō has significant variations in elevation — a maximum elevation change of 354 m around an average of 183 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 844 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,489 m.

The land around Sayō is covered by trees (76%) within 3 km, trees (89%) within 16 km, and trees (64%) and water (23%) within 80 km.

3 km
354 m
16 km
844 m
80 km
1,489 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Kamigōri 14 km · Yamazakichō-nakabirose 17 km · Shisō 19 km · Hayashino 19 km · Tatsunochō-tominaga 23 km · Aioi 24 km · Tatsuno 25 km · Bizen 27 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 Sayō (35.0027°, 134.359°, elevation 155 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).