Iida weather in December

In December, Iida sees average daytime highs of 5°C and overnight lows near -3°C, with 100 mm of precipitation across 12 wet days and about 9.6 hours of daylight. It is the 10th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 8°C in the first days to 3°C by the end. The sky is clear or mostly clear about 43% 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 Iida's 1st-clearest and 6th-windiest month. For the whole year in context, see Iida's year-round climate.

Daytime high: 5°; 10th warmest
Overnight low: -3°; 3rd coldest
Precipitation: 100 mm; 12 wet days
Daylight: 9 h 36 min; 6:57 AM – 4:33 PM
Cloud cover: 48%; 1st clearest
Wind: 6 km/h; 6th windiest
Solar energy: 2.52 kWh/m²
Travel score: 0.3; out of 10

Iida is city in Nagano Prefecture, Japan.

Density: 154/km²; people per km²
Founded: 1937

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← November Iida year-round climate January →Best places to visit in December

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 8°C in the first days to 3°C by the end.

A typical December day in Iida reaches about 5°C in the afternoon and slips back to -3°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 0°C and 10°C. Set against its neighbours, December runs about 6°C cooler than November and about 3°C warmer than January.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°C)	8	8	8	7	7	7	7	6	6	6	6	6	5	5	5	5	5	5	4	4	4	4	4	4	4	3	3	3	3	3	3
Avg low (°C)	0	0	0	-1	-1	-1	-1	-1	-2	-2	-2	-2	-3	-3	-3	-3	-3	-4	-4	-4	-4	-4	-4	-5	-5	-5	-5	-5	-5	-5	-6

	Avg high (°C)	Avg low (°C)
1	8	0
2	8	0
3	8	0
4	7	-1
5	7	-1
6	7	-1
7	7	-1
8	6	-1
9	6	-2
10	6	-2
11	6	-2
12	6	-2
13	5	-3
14	5	-3
15	5	-3
16	5	-3
17	5	-3
18	5	-4
19	4	-4
20	4	-4
21	4	-4
22	4	-4
23	4	-4
24	4	-5
25	4	-5
26	3	-5
27	3	-5
28	3	-5
29	3	-5
30	3	-5
31	3	-6

How December really feels in Iida

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

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

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

Iida 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.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	2° / -7°	99	11.7	11	9.9	0.0
Feb	3° / -6°	107	10.2	8.1	10.7	0.0
Mar	8° / -2°	171	13.1	7	11.7	1.1
Apr	14° / 4°	174	12.9	1.4	12.9	3.6
May	19° / 9°	191	13.7	0	13.8	5.4
Jun	22° / 14°	263	18	0	14.4	5.0
Jul	25° / 18°	308	20.3	0	14.2	5.0
Aug	27° / 19°	184	18.6	0	13.3	5.3
Sep	23° / 15°	228	15.5	0	12.2	5.7
Oct	18° / 9°	210	12.9	0	11.1	5.3
Nov	11° / 3°	126	10.4	1.2	10.1	2.9
Dec	5° / -3°	100	12	7.9	9.6	0.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in December, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of December, with mostly cloudy or overcast conditions the remaining 39%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	58	59	59	58	59	58	59	59	59	60	59	60	60	60	60	61	61	61	62	62	63	63	63	64	64	63	64	63	63	63	63
Cloudier (%)	42	41	41	42	41	42	41	41	41	40	41	40	40	40	40	39	39	39	38	38	37	37	37	36	36	37	36	37	37	37	37

	Clearer (%)	Cloudier (%)
1	58	42
2	59	41
3	59	41
4	58	42
5	59	41
6	58	42
7	59	41
8	59	41
9	59	41
10	60	40
11	59	41
12	60	40
13	60	40
14	60	40
15	60	40
16	61	39
17	61	39
18	61	39
19	62	38
20	62	38
21	63	37
22	63	37
23	63	37
24	64	36
25	64	36
26	63	37
27	64	36
28	63	37
29	63	37
30	63	37
31	63	37

Chance of precipitation in December

Any precipitationSnow

Iida gets around 100 mm of rain and snow over 12 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 39% and peaks near 40% on the wettest days, and about 8 days bring snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	36	36	37	37	37	38	38	38	39	39	39	40	40	40	40	40	40	40	40	40	39	39	39	39	38	38	38	38	38	37	37
Snow chance (%)	12	13	14	15	16	17	18	19	21	22	23	24	25	25	26	27	28	28	29	29	30	30	30	31	31	31	32	32	32	33	33

	Rain chance (%)	Snow chance (%)
1	36	12
2	36	13
3	37	14
4	37	15
5	37	16
6	38	17
7	38	18
8	38	19
9	39	21
10	39	22
11	39	23
12	40	24
13	40	25
14	40	25
15	40	26
16	40	27
17	40	28
18	40	28
19	40	29
20	40	29
21	39	30
22	39	30
23	39	30
24	39	31
25	38	31
26	38	31
27	38	32
28	38	32
29	38	32
30	37	33
31	37	33

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.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in December

Winds average 6 km/h in December.

Across December, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (km/h)	5	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	5	calm
2	6	calm
3	6	calm
4	6	calm
5	6	calm
6	6	calm
7	6	calm
8	6	calm
9	6	calm
10	6	calm
11	6	calm
12	6	calm
13	6	calm
14	6	calm
15	6	calm
16	6	calm
17	6	calm
18	6	calm
19	6	calm
20	6	calm
21	6	calm
22	6	calm
23	6	calm
24	6	calm
25	6	calm
26	6	calm
27	6	calm
28	6	calm
29	6	calm
30	6	calm
31	6	calm

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 6:45 AM to 7:03 AM, and sunset from 4:32 PM to 4:41 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	9.8	9.8	9.7	9.7	9.7	9.7	9.7	9.7	9.7	9.7	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6
Sunrise (AM)	6:45	6:46	6:47	6:48	6:49	6:49	6:50	6:51	6:52	6:53	6:53	6:54	6:55	6:55	6:56	6:57	6:57	6:58	6:58	6:59	6:59	7:00	7:00	7:01	7:01	7:01	7:02	7:02	7:02	7:03	7:03
Sunset (PM)	4:32	4:32	4:32	4:31	4:31	4:31	4:32	4:32	4:32	4:32	4:32	4:32	4:32	4:33	4:33	4:33	4:34	4:34	4:34	4:35	4:35	4:36	4:36	4:37	4:37	4:38	4:38	4:39	4:39	4:40	4:41

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	9.8	6:45	4:32
2	9.8	6:46	4:32
3	9.7	6:47	4:32
4	9.7	6:48	4:31
5	9.7	6:49	4:31
6	9.7	6:49	4:31
7	9.7	6:50	4:32
8	9.7	6:51	4:32
9	9.7	6:52	4:32
10	9.7	6:53	4:32
11	9.6	6:53	4:32
12	9.6	6:54	4:32
13	9.6	6:55	4:32
14	9.6	6:55	4:33
15	9.6	6:56	4:33
16	9.6	6:57	4:33
17	9.6	6:57	4:34
18	9.6	6:58	4:34
19	9.6	6:58	4:34
20	9.6	6:59	4:35
21	9.6	6:59	4:35
22	9.6	7:00	4:36
23	9.6	7:00	4:36
24	9.6	7:01	4:37
25	9.6	7:01	4:37
26	9.6	7:01	4:38
27	9.6	7:02	4:38
28	9.6	7:02	4:39
29	9.6	7:02	4:39
30	9.6	7:03	4:40
31	9.6	7:03	4:41

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.52 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.52 kWh/m² to a high of 5.47 kWh/m² in May across the year — December's 2.52 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.6	2.6	2.6	2.6	2.6	2.6	2.6	2.7	2.7	2.7	2.7	2.7	2.8
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	2.5	Moderate
2	2.5	Moderate
3	2.5	Moderate
4	2.5	Moderate
5	2.5	Moderate
6	2.5	Moderate
7	2.5	Moderate
8	2.5	Moderate
9	2.5	Moderate
10	2.5	Moderate
11	2.5	Moderate
12	2.5	Moderate
13	2.5	Moderate
14	2.5	Moderate
15	2.5	Moderate
16	2.5	Moderate
17	2.5	Moderate
18	2.5	Moderate
19	2.6	Moderate
20	2.6	Moderate
21	2.6	Moderate
22	2.6	Moderate
23	2.6	Moderate
24	2.6	Moderate
25	2.6	Moderate
26	2.7	Moderate
27	2.7	Moderate
28	2.7	Moderate
29	2.7	Moderate
30	2.7	Moderate
31	2.8	Moderate

Planning a trip in December

Is December a good time to visit Iida?

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

0.3

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 Iida.

What to pack for Iida in December

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

In December, Iida sees daytime highs around 5°C and nights near -3°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 12 days see rain.

a warm layera heavy coatrain gear

UV index in Iida 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 Iida peaks around July 13 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (moderate).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	3	5	6	7	9	10	11	9	10	6	4	2
Level	Moderate	Moderate	High	Very high	Very high	Extreme	Extreme	Very high	Very high	High	Moderate	Moderate

	UV index (midday)	Level
Jan	3	Moderate
Feb	5	Moderate
Mar	6	High
Apr	7	Very high
May	9	Very high
Jun	10	Extreme
Jul	11	Extreme
Aug	9	Very high
Sep	10	Very high
Oct	6	High
Nov	4	Moderate
Dec	2	Moderate

Air quality in Iida 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 Iida is worst in April — around 18 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 8 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	9	11	16	18	17	15	11	11	10	9	8	8
Level	Good	Good	Moderate	Moderate	Moderate	Moderate	Good	Good	Good	Good	Good	Good

	PM2.5 (µg/m³)	Level
Jan	9	Good
Feb	11	Good
Mar	16	Moderate
Apr	18	Moderate
May	17	Moderate
Jun	15	Moderate
Jul	11	Good
Aug	11	Good
Sep	10	Good
Oct	9	Good
Nov	8	Good
Dec	8	Good

Location & terrain

Where is Iida?

Iida sits at 35.5°N, 137.8°E, 517 m above sea level, in Japan. The nearest listed city is Komagane, 24 km away.

Topography around Iida

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

Within 3 km, the terrain around Iida has large variations in elevation — a maximum elevation change of 733 m around an average of 565 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,037 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,167 m.

The land around Iida is covered by artificial surfaces (53%) and trees (36%) within 3 km, trees (86%) within 16 km, and trees (90%) within 80 km.

3 km

733 m

artificial surfaces 53%

16 km

2,037 m

trees 86%

80 km

3,167 m

trees 90%

treesgrasslandcroplandartificial surfaceswater

← November Iida year-round climate January →Best places to visit in December

December weather nearby: Komagane 24 km · Nakatsugawa 29 km · Ina 36 km · Ena 40 km · Minamiminowa 42 km · Kinoshita 45 km · Tatsuno 54 km · Mizunami 54 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

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 Iida (35.5196°, 137.8207°, elevation 517 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).

	Avg high (°C)	Avg low (°C)
1	8	0
2	8	0
3	8	0
4	7	-1
5	7	-1
6	7	-1
7	7	-1
8	6	-1
9	6	-2
10	6	-2
11	6	-2
12	6	-2
13	5	-3
14	5	-3
15	5	-3
16	5	-3
17	5	-3
18	5	-4
19	4	-4
20	4	-4
21	4	-4
22	4	-4
23	4	-4
24	4	-5
25	4	-5
26	3	-5
27	3	-5
28	3	-5
29	3	-5
30	3	-5
31	3	-6

	Clearer (%)	Cloudier (%)
1	58	42
2	59	41
3	59	41
4	58	42
5	59	41
6	58	42
7	59	41
8	59	41
9	59	41
10	60	40
11	59	41
12	60	40
13	60	40
14	60	40
15	60	40
16	61	39
17	61	39
18	61	39
19	62	38
20	62	38
21	63	37
22	63	37
23	63	37
24	64	36
25	64	36
26	63	37
27	64	36
28	63	37
29	63	37
30	63	37
31	63	37

	Rain chance (%)	Snow chance (%)
1	36	12
2	36	13
3	37	14
4	37	15
5	37	16
6	38	17
7	38	18
8	38	19
9	39	21
10	39	22
11	39	23
12	40	24
13	40	25
14	40	25
15	40	26
16	40	27
17	40	28
18	40	28
19	40	29
20	40	29
21	39	30
22	39	30
23	39	30
24	39	31
25	38	31
26	38	31
27	38	32
28	38	32
29	38	32
30	37	33
31	37	33

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	8	0
2	8	0
3	8	0
4	7	-1
5	7	-1
6	7	-1
7	7	-1
8	6	-1
9	6	-2
10	6	-2
11	6	-2
12	6	-2
13	5	-3
14	5	-3
15	5	-3
16	5	-3
17	5	-3
18	5	-4
19	4	-4
20	4	-4
21	4	-4
22	4	-4
23	4	-4
24	4	-5
25	4	-5
26	3	-5
27	3	-5
28	3	-5
29	3	-5
30	3	-5
31	3	-6

	Clearer (%)	Cloudier (%)
1	58	42
2	59	41
3	59	41
4	58	42
5	59	41
6	58	42
7	59	41
8	59	41
9	59	41
10	60	40
11	59	41
12	60	40
13	60	40
14	60	40
15	60	40
16	61	39
17	61	39
18	61	39
19	62	38
20	62	38
21	63	37
22	63	37
23	63	37
24	64	36
25	64	36
26	63	37
27	64	36
28	63	37
29	63	37
30	63	37
31	63	37

	Rain chance (%)	Snow chance (%)
1	36	12
2	36	13
3	37	14
4	37	15
5	37	16
6	38	17
7	38	18
8	38	19
9	39	21
10	39	22
11	39	23
12	40	24
13	40	25
14	40	25
15	40	26
16	40	27
17	40	28
18	40	28
19	40	29
20	40	29
21	39	30
22	39	30
23	39	30
24	39	31
25	38	31
26	38	31
27	38	32
28	38	32
29	38	32
30	37	33
31	37	33

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	8	0
2	8	0
3	8	0
4	7	-1
5	7	-1
6	7	-1
7	7	-1
8	6	-1
9	6	-2
10	6	-2
11	6	-2
12	6	-2
13	5	-3
14	5	-3
15	5	-3
16	5	-3
17	5	-3
18	5	-4
19	4	-4
20	4	-4
21	4	-4
22	4	-4
23	4	-4
24	4	-5
25	4	-5
26	3	-5
27	3	-5
28	3	-5
29	3	-5
30	3	-5
31	3	-6

	Clearer (%)	Cloudier (%)
1	58	42
2	59	41
3	59	41
4	58	42
5	59	41
6	58	42
7	59	41
8	59	41
9	59	41
10	60	40
11	59	41
12	60	40
13	60	40
14	60	40
15	60	40
16	61	39
17	61	39
18	61	39
19	62	38
20	62	38
21	63	37
22	63	37
23	63	37
24	64	36
25	64	36
26	63	37
27	64	36
28	63	37
29	63	37
30	63	37
31	63	37

	Rain chance (%)	Snow chance (%)
1	36	12
2	36	13
3	37	14
4	37	15
5	37	16
6	38	17
7	38	18
8	38	19
9	39	21
10	39	22
11	39	23
12	40	24
13	40	25
14	40	25
15	40	26
16	40	27
17	40	28
18	40	28
19	40	29
20	40	29
21	39	30
22	39	30
23	39	30
24	39	31
25	38	31
26	38	31
27	38	32
28	38	32
29	38	32
30	37	33
31	37	33

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100