Ina weather in December

In December, Ina sees average daytime highs of 5°C and overnight lows near -4°C, with 80 mm of precipitation across 10.4 wet days and about 9.6 hours of daylight. It is the 10th-warmest and 12th-wettest month of the year here.

Highs ease over the month, from about 7°C in the first days to 3°C by the end. The sky is clear or mostly clear about 39% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 42 min at the start of December to 9 h 36 min by month's end. Set against the rest of the year, December is Ina's 1st-clearest and 6th-windiest month. For the whole year in context, see Ina's year-round climate.

Daytime high
10th warmest
Overnight low
-4°
3rd coldest
Precipitation
80 mm
10.4 wet days
Daylight
9 h 36 min
6:57 AM – 4:32 PM
Cloud cover
51%
1st clearest
Wind
6 km/h
6th windiest
Solar energy
2.57 kWh/m²
Travel score
0.2
out of 10

Ina is city in Nagano prefecture, Japan.

Density
102/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 7°C in the first days to 3°C by the end.

A typical December day in Ina reaches about 5°C in the afternoon and slips back to -4°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 0°C and 9°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

-10°10°151015202531
Avg high (°C)Avg low (°C)
18-1
27-1
37-1
47-1
57-2
66-2
76-2
86-2
96-3
106-3
115-3
125-3
135-3
145-4
155-4
165-4
174-4
184-4
194-5
204-5
214-5
224-5
234-5
243-5
253-6
263-6
273-6
283-6
293-6
303-6
313-6

How December really feels in Ina

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 31 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
31
wind chill below the day's low

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

Ina weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -8°8310.710.59.80.0
Feb / -7°889.38.310.60.0
Mar / -3°14413.27.811.70.9
Apr13° / 13312.11.912.93.6
May18° / 13711.9013.95.6
Jun22° / 14°18115.2014.45.4
Jul25° / 17°20316.5014.25.6
Aug26° / 18°12114.1013.45.9
Sep23° / 15°16412.5012.26.1
Oct17° / 17611.7011.15.2
Nov11° / 989.71.110.12.7
Dec / -4°8010.47.59.60.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in December, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 19% of December, with mostly cloudy or overcast conditions the remaining 41%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35644
45743
55743
65743
75743
85842
95743
105842
115842
125842
135842
145842
155941
165941
175941
185941
196040
206040
216040
226040
236139
246139
256139
266238
276139
286139
296139
306139
316139

Chance of precipitation in December

Any precipitationSnow

Ina gets around 80 mm of rain and snow over 10.4 wet days in December, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 34% and peaks near 35% on the wettest days, and about 8 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
13211
23212
33313
43314
53315
63316
73317
83418
93419
103420
113421
123422
133523
143523
153524
163525
173526
183426
193427
203428
213428
223429
233329
243329
253330
263330
273330
283331
293331
303332
313332

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 (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 6 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 42 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 6 minutes over December. Sunrise moves from 6:46 AM to 7:03 AM, and sunset from 4:30 PM to 4:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.76:464:30
29.76:464:30
39.76:474:30
49.76:484:30
59.76:494:30
69.76:504:30
79.76:514:30
89.66:514:30
99.66:524:30
109.66:534:30
119.66:544:31
129.66:544:31
139.66:554:31
149.66:564:31
159.66:564:32
169.66:574:32
179.66:574:32
189.66:584:33
199.66:594:33
209.66:594:33
219.67:004:34
229.67:004:34
239.67:014:35
249.67:014:35
259.67:014:36
269.67:024:36
279.67:024:37
289.67:024:37
299.67:034:38
309.67:034:39
319.67:034:39

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.57 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.57 kWh/m² to a high of 5.6 kWh/m² in May across the year — December's 2.57 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.6Moderate
22.5Moderate
32.5Moderate
42.5Moderate
52.5Moderate
62.5Moderate
72.5Moderate
82.5Moderate
92.5Moderate
102.5Moderate
112.5Moderate
122.5Moderate
132.5Moderate
142.6Moderate
152.6Moderate
162.6Moderate
172.6Moderate
182.6Moderate
192.6Moderate
202.6Moderate
212.6Moderate
222.6Moderate
232.7Moderate
242.7Moderate
252.7Moderate
262.7Moderate
272.7Moderate
282.8Moderate
292.8Moderate
302.8Moderate
312.8Moderate
Planning a trip in December

Is December a good time to visit Ina?

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

0.2
Sightseeing
10th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Ina.

What to pack for Ina in December

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

In December, Ina sees daytime highs around 5°C and nights near -4°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 10 days see rain.

a warm layera heavy coatrain gear

UV index in Ina 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 Ina peaks around July 14 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highExtremeVery highModerateJul 14UV 11Dec 21UV 2
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Ina 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 Ina is worst in April — around 18 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1918 µg/m³Dec 178 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar17Moderate
Apr18Moderate
May17Moderate
Jun16Moderate
Jul13Moderate
Aug12Good
Sep10Good
Oct10Good
Nov9Good
Dec8Good
Location & terrain

Where is Ina?

Ina sits at 35.8°N, 138.0°E, 638 m above sea level, in Japan. The nearest listed city is Minamiminowa, 5.0 km away.

Topography around Ina

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

Within 3 km, the terrain around Ina has significant variations in elevation — a maximum elevation change of 417 m around an average of 678 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 2,406 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,069 m.

The land around Ina is covered by artificial surfaces (36%), cropland (35%) and trees (20%) within 3 km, trees (76%) within 16 km, and trees (89%) within 80 km.

3 km
417 m
16 km
2,406 m
80 km
3,069 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Minamiminowa 5.0 km · Kinoshita 9.0 km · Komagane 12 km · Tatsuno 18 km · Chino 26 km · Okaya 27 km · Suwa 27 km · Shimosuwa 29 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 Ina (35.8276°, 137.9538°, elevation 638 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. 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).