Niihama weather in December

In December, Niihama sees average daytime highs of 10°C and overnight lows near 5°C, with 90 mm of precipitation across 12.8 wet days and about 9.8 hours of daylight. It is the 10th-warmest and 10th-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 26% 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 48 min by month's end. Set against the rest of the year, December is Niihama's 3rd-clearest and 2nd-windiest month. For the whole year in context, see Niihama's year-round climate.

Daytime high
10°
10th warmest
Overnight low
3rd coldest
Precipitation
90 mm
12.8 wet days
Daylight
9 h 48 min
7:10 AM – 4:55 PM
Cloud cover
56%
3rd clearest
Wind
12 km/h
2nd windiest
Solar energy
2.35 kWh/m²
Travel score
2.3
out of 10

Niihama is city in Ehime Prefecture, Japan.

Density
525/km²
people per km²
Founded
1937

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 Niihama reaches about 10°C in the afternoon and slips back to 5°C overnight — a 5°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 5°C cooler than November and about 3°C warmer than January.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1137
2127
3127
4127
5127
6127
7116
8116
9116
10116
11116
12116
13106
14105
15105
16105
17105
18105
19105
20105
2195
2295
2395
2495
2594
2694
2794
2894
2994
3094
3194

How December really feels in Niihama

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.

Niihama 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 / 7813.53.4101.1
Feb / 8412.13.210.71.5
Mar12° / 12213.4111.72.9
Apr17° / 10°13411.60.112.85.1
May21° / 15°15811.2013.76.3
Jun24° / 19°24915.1014.25.7
Jul28° / 23°22815.60145.1
Aug29° / 24°15113.8013.35.0
Sep26° / 21°21614.1012.26.0
Oct21° / 16°16611011.16.4
Nov15° / 10°909.9010.24.8
Dec10° / 9012.81.69.82.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% 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 48%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15545
25446
35446
45446
55446
65446
75347
85248
95248
105149
115149
125050
134951
144852
154951
164951
174951
184951
195050
205149
215149
225248
235248
245347
255347
265446
275446
285545
295545
305545
315545

Chance of precipitation in December

Any precipitationSnow

Niihama gets around 90 mm of rain and snow over 12.8 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 41% and peaks near 41% on the wettest days, and about 2 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1391
2391
3402
4402
5402
6402
7412
8412
9413
10413
11413
12413
13414
14414
15414
16415
17415
18415
19416
20416
21416
22417
23417
24418
25418
26418
27419
28419
29409
30409
31409

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 (%)
1982
2982
3982
4991
5991
6991
7991
8991
9991
10991
11991
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 12 km/h in December.

Across December, daily wind ranges from about 11 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712light breeze
1812light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 54 min at the start of December to 9 h 48 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 6:59 AM to 7:17 AM, and sunset from 4:54 PM to 5:03 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.96:594:54
29.97:004:54
39.97:014:53
49.97:024:53
59.87:034:53
69.87:034:54
79.87:044:54
89.87:054:54
99.87:064:54
109.87:064:54
119.87:074:54
129.87:084:54
139.87:094:55
149.87:094:55
159.87:104:55
169.87:104:55
179.77:114:56
189.77:124:56
199.77:124:57
209.77:134:57
219.77:134:57
229.77:144:58
239.77:144:58
249.77:154:59
259.77:154:59
269.77:155:00
279.77:165:00
289.87:165:01
299.87:165:02
309.87:175:02
319.87:175:03

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.35 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.35 kWh/m² to a high of 5.61 kWh/m² in May across the year — December's 2.35 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.5Moderate
22.4Moderate
32.4Moderate
42.4Moderate
52.4Moderate
62.4Moderate
72.4Moderate
82.4Moderate
92.4Moderate
102.3Moderate
112.3Moderate
122.3Moderate
132.3Moderate
142.3Moderate
152.3Moderate
162.3Moderate
172.3Moderate
182.3Moderate
192.3Moderate
202.3Moderate
212.3Moderate
222.4Moderate
232.4Moderate
242.4Moderate
252.4Moderate
262.4Moderate
272.4Moderate
282.4Moderate
292.4Moderate
302.5Moderate
312.5Moderate
Planning a trip in December

Hazard calendar for Niihama

In seasonPeak

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

Niihama 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 Niihama?

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

2.3
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 Niihama.

What to pack for Niihama in December

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

In December, Niihama sees daytime highs around 10°C and nights near 5°C. Pack a warm layer. Worth having: rain gear. About 13 days see rain.

a warm layerrain gear

Sea temperature near Niihama 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 19 km away) is warmest in August at about 28°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 3 to Nov 13 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul25Warm
Aug28Warm
Sep27Warm
Oct24Refreshing
Nov20Cool
Dec17Cool

UV index in Niihama 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 Niihama peaks around July 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 12UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Niihama 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 Niihama is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1321 µg/m³Oct 1311 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb16Moderate
Mar20Moderate
Apr22Moderate
May19Moderate
Jun16Moderate
Jul13Moderate
Aug12Moderate
Sep11Good
Oct11Good
Nov12Good
Dec11Good
Location & terrain

Where is Niihama?

Niihama sits at 34.0°N, 133.3°E, 13 m above sea level, in Japan. The nearest listed city is Saijō, 12 km away.

Topography around Niihama

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

Within 3 km, the terrain around Niihama has only modest variations in elevation — a maximum elevation change of 239 m around an average of 31 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,850 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,946 m.

The land around Niihama is covered by artificial surfaces (61%) and trees (22%) within 3 km, water (46%) and trees (41%) within 16 km, and trees (60%) and water (31%) within 80 km.

3 km
239 m
16 km
1,850 m
80 km
1,946 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Saijō 12 km · Shikokuchūō 23 km · Kawanoechō 26 km · Imabari 31 km · Kan’onjichō 36 km · Innoshima 38 km · Tōon 43 km · Mitoyo 44 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 Niihama (33.9605°, 133.3052°, elevation 13 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).