Ranzan weather in January

In January, Ranzan sees average daytime highs of 7°C and overnight lows near -1°C, with 62 mm of precipitation across 6.7 wet days and about 9.8 hours of daylight. It is the 12th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 7°C through the month. The sky is clear or mostly clear about 59% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 36 min at the start of January to 10 h 12 min by month's end. Set against the rest of the year, January is Ranzan's 1st-clearest and 3rd-windiest month. For the whole year in context, see Ranzan's year-round climate.

Daytime high
12th warmest
Overnight low
-1°
1st coldest
Precipitation
62 mm
6.7 wet days
Daylight
9 h 48 min
6:58 AM – 4:46 PM
Cloud cover
39%
1st clearest
Wind
8 km/h
3rd windiest
Solar energy
2.92 kWh/m²
Travel score
1.2
out of 10

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 7°C through the month.

A typical January day in Ranzan reaches about 7°C in the afternoon and slips back to -1°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 4°C and 11°C. Set against its neighbours, January runs about 3°C cooler than December and about 1°C cooler than February.

-10°-5°10°15°151015202531
Avg high (°C)Avg low (°C)
180
280
380
480
580
680
780
88-1
98-1
107-1
117-1
127-1
137-1
147-1
157-1
167-1
177-1
187-1
197-1
207-1
217-1
227-1
237-1
247-2
257-2
267-2
277-2
287-2
297-2
307-2
317-2

How January really feels in Ranzan

Once humidity and wind are folded in, January 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 January is cold — wind chill drags the overnight "feels like" below the raw low.

Ranzan weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°626.73.79.81.2
Feb / -1°597.64.110.61.6
Mar12° / 111134.511.72.9
Apr17° / 12312.80.912.95.0
May22° / 13°14814.4013.95.8
Jun24° / 18°19918.1014.45.2
Jul28° / 22°22220.8014.24.4
Aug29° / 23°18019.7013.44.2
Sep25° / 19°22317.3012.25.4
Oct20° / 13°21714.5011.15.6
Nov15° / 819.20.210.14.6
Dec10° / 547.21.39.62.5

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 59% of the time in January, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of January, with mostly cloudy or overcast conditions the remaining 27%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17921
27921
37921
47921
57822
67822
77822
87723
97624
107624
117525
127426
137327
147228
157129
167030
177030
186931
196832
206832
216832
226832
236832
246832
256931
266931
277030
287030
297030
307129
317129

Chance of precipitation in January

Any precipitationSnow

Ranzan gets around 62 mm of rain and snow over 6.7 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 22% and peaks near 25% on the wettest days, and about 4 days bring snow. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1176
2176
3176
4177
5187
6188
7198
8199
92010
102110
112111
122212
132313
142314
152414
162415
172515
182516
192516
202516
212516
222516
232516
242515
252515
262415
272414
282414
292314
302313
312313

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

Most of January feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, January 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 January

Winds average 8 km/h in January.

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

0246810151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 36 min at the start of January to 10 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over January. Sunrise moves from 6:58 AM to 6:51 AM, and sunset from 4:34 PM to 5:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.66:584:34
29.66:584:34
39.66:594:35
49.66:594:36
59.66:594:37
69.66:594:37
79.76:594:38
89.76:594:39
99.76:594:40
109.76:594:41
119.76:594:42
129.76:594:42
139.76:594:43
149.86:584:44
159.86:584:45
169.86:584:46
179.86:584:47
189.86:574:48
199.96:574:49
209.96:574:50
219.96:564:51
229.96:564:52
2310.06:564:53
2410.06:554:54
2510.06:554:55
2610.06:544:56
2710.16:544:57
2810.16:534:58
2910.16:524:59
3010.16:525:00
3110.26:515:01

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.92 kWh/m².

For context, solar energy here swings from a low near 2.44 kWh/m² to a high of 5.08 kWh/m² in May across the year — January's 2.92 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
12.7Moderate
22.8Moderate
32.8Moderate
42.8Moderate
52.8Moderate
62.8Moderate
72.8Moderate
82.8Moderate
92.8Moderate
102.8Moderate
112.8Moderate
122.8Moderate
132.8Moderate
142.8Moderate
152.8Moderate
162.8Moderate
172.8Moderate
182.9Moderate
192.9Moderate
202.9Moderate
212.9Moderate
223.0Moderate
233.0Moderate
243.0Moderate
253.1Moderate
263.1Moderate
273.1Moderate
283.2Moderate
293.2Moderate
303.2Moderate
313.3Moderate
Planning a trip in January

Hazard calendar for Ranzan

In seasonPeak

None of Ranzan's seasonal hazards are active in January. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Ranzan's rainy season runs March–October, when most of the year's rain falls.

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

Is January a good time to visit Ranzan?

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

1.2
Sightseeing
12th-best month of the year
0.0
Beach & pool
10th-best month of the year

January is a weaker month for outdoor sightseeing in Ranzan.

What to pack for Ranzan in January

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

In January, Ranzan sees daytime highs around 7°C and nights near -1°C. Pack a warm layer. Worth having: a heavy coat. About 7 days see rain.

a warm layera heavy coat

Sea temperature near Ranzan in January

The nearest coast averages about 14°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 70 km away) is warmest in August at about 26°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 3 — about 4.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Ranzan in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ranzan peaks around July 15 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 highModerateJul 15UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep8Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Ranzan in January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January falls, not just the annual average.

Air quality in Ranzan is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1426 µg/m³Dec 1814 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb21Moderate
Mar25Moderate
Apr26Moderate
May24Moderate
Jun20Moderate
Jul17Moderate
Aug16Moderate
Sep16Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Ranzan?

Ranzan sits at 36.1°N, 139.3°E, 74 m above sea level, in Japan. The nearest listed city is Ogawamachi, 4.0 km away.

Topography around Ranzan

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

Within 3 km, the terrain around Ranzan has only modest variations in elevation — a maximum elevation change of 191 m around an average of 79 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 952 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,579 m.

The land around Ranzan is covered by trees (56%) and artificial surfaces (23%) within 3 km, trees (47%) and artificial surfaces (28%) within 16 km, and trees (54%) and artificial surfaces (27%) within 80 km.

3 km
191 m
16 km
952 m
80 km
2,579 m
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Ogawamachi 4.0 km · Yamata 6.0 km · Higashi-Matsuyama 9.0 km · Kumagaya 11 km · Yorii 13 km · Sakado 13 km · Fukiage-fujimi 13 km · Tsurugashima 13 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 Ranzan (36.0553°, 139.315°, elevation 74 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. 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).