Iwaki weather in December

In December, Iwaki sees average daytime highs of 10°C and overnight lows near 6°C, with 73 mm of precipitation across 8.6 wet days and about 9.5 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 12°C in the first days to 8°C by the end. The sky is clear or mostly clear about 54% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of December to 9 h 30 min by month's end. Set against the rest of the year, December is Iwaki's 1st-clearest and 3rd-windiest month. For the whole year in context, see Iwaki's year-round climate.

Daytime high
10°
9th warmest
Overnight low
4th coldest
Precipitation
73 mm
8.6 wet days
Daylight
9 h 30 min
6:49 AM – 4:17 PM
Cloud cover
43%
1st clearest
Wind
18 km/h
3rd windiest
Solar energy
2.32 kWh/m²
Travel score
2.3
out of 10

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 8°C by the end.

A typical December day in Iwaki reaches about 10°C in the afternoon and slips back to 6°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 13°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)
1128
2127
3127
4117
5117
6117
7117
8116
9116
10106
11106
12106
13106
14106
15106
16105
17105
1895
1995
2095
2195
2295
2395
2495
2594
2694
2784
2884
2984
3084
3184

How December really feels in Iwaki

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 2 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
2
wind chill below the day's low

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

Iwaki weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 7181.59.71.1
Feb / 6881.910.61.1
Mar10° / 12512.1111.72.1
Apr13° / 13411.90.212.93.6
May17° / 13°145120145.1
Jun20° / 17°14713.7014.55.4
Jul23° / 20°17514.5014.35.9
Aug25° / 22°12611.8013.46.5
Sep23° / 20°19214.1012.35.9
Oct19° / 15°22313.40115.6
Nov14° / 10°1119.80104.4
Dec10° / 738.60.29.52.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% of the time in December, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 31%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16139
26139
36238
46238
56238
66337
76337
86436
96436
106535
116634
126733
136733
146931
156931
166931
177030
187129
197228
207228
217327
227426
237426
247426
257426
267525
277624
287624
297624
307624
317624

Chance of precipitation in December

Any precipitationSnow

Iwaki gets around 73 mm of rain and snow over 8.6 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 27% and peaks near 33% on the wettest days, and about 0 day brings snow. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1330
2330
3330
4330
5330
6320
7320
8320
9310
10300
11301
12291
13281
14281
15271
16261
17261
18251
19251
20241
21241
22241
23231
24231
25231
26221
27221
28211
29211
30211
31212

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 (%)
1982
2991
3991
4991
5991
6991
7991
81000
91000
101000
111000
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 18 km/h in December.

Across December, daily wind ranges from about 17 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze
3119light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 36 min at the start of December to 9 h 30 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 6:37 AM to 6:55 AM, and sunset from 4:15 PM to 4:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.66:374:15
29.66:384:15
39.66:394:15
49.66:404:15
59.66:404:15
69.66:414:15
79.66:424:15
89.56:434:15
99.56:444:15
109.56:444:15
119.56:454:16
129.56:464:16
139.56:474:16
149.56:474:16
159.56:484:16
169.56:494:17
179.56:494:17
189.56:504:17
199.56:504:18
209.56:514:18
219.56:514:19
229.56:524:19
239.56:524:19
249.56:534:20
259.56:534:21
269.56:544:21
279.56:544:22
289.56:544:22
299.56:544:23
309.56:554:24
319.56:554:24

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.32 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.32 kWh/m² to a high of 5.47 kWh/m² in May across the year — December's 2.32 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.3Moderate
22.3Moderate
32.3Moderate
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
182.4Moderate
192.4Moderate
202.4Moderate
212.4Moderate
222.4Moderate
232.4Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.6Moderate
Planning a trip in December

Hazard calendar for Iwaki

In seasonPeak

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

Iwaki 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 Iwaki?

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

2.3
Sightseeing
9th-best month of the year
0.0
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Iwaki.

What to pack for Iwaki in December

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

In December, Iwaki sees daytime highs around 10°C and nights near 6°C. Pack a warm layer. Worth having: rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Iwaki 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 19 km away) is warmest in August at about 24°C and coldest in March near 12°C.

It's comfortable for a long swim from Jul 1 to Oct 22 — about 3.7 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb12Bracing
Mar12Bracing
Apr14Bracing
May16Cool
Jun19Cool
Jul21Refreshing
Aug24Refreshing
Sep23Refreshing
Oct20Refreshing
Nov18Cool
Dec16Cool

UV index in Iwaki 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 Iwaki peaks around July 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug9Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Iwaki 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 Iwaki is worst in April — around 19 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (December, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 2219 µg/m³Dec 177 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb11Good
Mar17Moderate
Apr19Moderate
May19Moderate
Jun14Moderate
Jul12Moderate
Aug11Good
Sep10Good
Oct10Good
Nov9Good
Dec7Good
Location & terrain

Where is Iwaki?

Iwaki sits at 37.0°N, 140.9°E, 9 m above sea level, in Japan. The nearest listed city is Kitaibaraki, 32 km away.

Topography around Iwaki

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

Within 3 km, the terrain around Iwaki has only modest variations in elevation — a maximum elevation change of 129 m around an average of 35 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 776 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,678 m.

The land around Iwaki is covered by artificial surfaces (46%) and trees (41%) within 3 km, trees (57%) and water (22%) within 16 km, and trees (55%) and water (32%) within 80 km.

3 km
129 m
16 km
776 m
80 km
1,678 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Kitaibaraki 32 km · Takahagi 40 km · Ishikawa 40 km · Tamura 49 km · Namie 49 km · Sukagawa 51 km · Funehikimachi-funehiki 52 km · Yabuki 53 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 Iwaki (37.05°, 140.8833°, elevation 9 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).