Nagai weather in January

In January, Nagai sees average daytime highs of 0°C and overnight lows near -5°C, with 190 mm of precipitation across 24.4 wet days and about 9.7 hours of daylight. It is the 12th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 0°C through the month. The sky is clear or mostly clear about 2% of the time in January, and the air most often feels dry.

Daylight stretches from about 9 h 24 min at the start of January to 10 hours by month's end. Set against the rest of the year, January is Nagai's 11th-clearest and 2nd-windiest month. For the whole year in context, see Nagai's year-round climate.

Daytime high
12th warmest
Overnight low
-5°
1st coldest
Precipitation
190 mm
24.4 wet days
Daylight
9 h 36 min
7:00 AM – 4:38 PM
Cloud cover
79%
11th clearest
Wind
11 km/h
2nd windiest
Solar energy
2.22 kWh/m²
Travel score
0.0
out of 10

Nagai is city in Yamagata Prefecture, Japan.

Density
145/km²
people per km²
Founded
1954

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 0°C through the month.

A typical January day in Nagai reaches about 0°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 -3°C and 4°C. Set against its neighbours, January runs about 3°C cooler than December and about 1°C cooler than February.

-10°-5°151015202531
Avg high (°C)Avg low (°C)
11-4
21-4
31-4
41-4
51-4
61-4
71-4
81-5
91-5
100-5
110-5
120-5
130-5
140-5
150-5
160-5
170-5
180-5
190-5
200-5
210-5
220-5
230-5
240-5
250-5
260-5
270-5
280-5
290-5
300-5
310-5

How January really feels in Nagai

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.

Nagai weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°19024.425.29.70.0
Feb / -5°13720.620.510.50.0
Mar / -2°14619.415.611.70.2
Apr11° / 11515.14.4132.5
May18° / 11614.20.1145.1
Jun22° / 14°15515.2014.65.4
Jul25° / 18°24119.9014.45.1
Aug26° / 19°18317.4013.55.4
Sep22° / 15°15515.3012.35.5
Oct16° / 13914.30.1114.5
Nov10° / 13417.55.59.91.7
Dec / -3°18123.219.29.40.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 12% of January, with mostly cloudy or overcast conditions the remaining 86%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11486
21288
31288
41288
51288
61387
71387
81387
91387
101387
111387
121387
131486
141486
151486
161486
171486
181486
191486
201486
211486
221486
231486
241486
251486
261585
271585
281585
291684
301684
311684

Chance of precipitation in January

Any precipitationSnow

Nagai gets around 190 mm of rain and snow over 24.4 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 78% and peaks near 80% on the wettest days, and about 25 days bring snow.

0%20%40%60%80%151015202531
Rain chance (%)Snow chance (%)
17977
27978
37979
47980
57980
67981
77881
87881
97881
107781
117781
127781
137781
147781
157781
167781
177781
187781
197781
207881
217881
227981
237981
248082
258082
268082
278082
288082
298082
308082
318082

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 11 km/h in January.

Across January, daily wind ranges from about 10 km/h on the calmest days to 11 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
1011calm
1111calm
1211calm
1311calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 9 h 24 min at the start of January to 10 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over January. Sunrise moves from 7:01 AM to 6:53 AM, and sunset from 4:25 PM to 4:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.47:014:25
29.47:014:26
39.47:014:26
49.47:024:27
59.47:024:28
69.57:024:29
79.57:024:30
89.57:024:30
99.57:024:31
109.57:024:32
119.57:014:33
129.57:014:34
139.67:014:35
149.67:014:36
159.67:014:37
169.67:004:38
179.67:004:39
189.77:004:40
199.76:594:41
209.76:594:42
219.76:594:43
229.86:584:44
239.86:584:45
249.86:574:46
259.86:574:47
269.96:564:48
279.96:554:49
289.96:554:50
2910.06:544:52
3010.06:534:53
3110.06:534:54

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 2.22 kWh/m².

For context, solar energy here swings from a low near 1.82 kWh/m² to a high of 5.35 kWh/m² in May across the year — January's 2.22 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.0Moderate
22.0Moderate
32.0Moderate
42.0Moderate
52.0Moderate
62.0Moderate
72.0Moderate
82.0Moderate
92.1Moderate
102.1Moderate
112.1Moderate
122.1Moderate
132.1Moderate
142.1Moderate
152.2Moderate
162.2Moderate
172.2Moderate
182.2Moderate
192.3Moderate
202.3Moderate
212.3Moderate
222.3Moderate
232.4Moderate
242.4Moderate
252.4Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.6Moderate
312.6Moderate
Planning a trip in January

Hazard calendar for Nagai

In seasonPeak

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

Nagai 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 January a good time to visit Nagai?

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

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

January is a weaker month for outdoor sightseeing in Nagai.

What to pack for Nagai in January

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

In January, Nagai sees daytime highs around 0°C and nights near -5°C. Pack a warm layer, a heavy coat and rain gear. About 24 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Nagai in January

The nearest coast averages about 12°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 58 km away) is warmest in August at about 26°C and coldest in March near 9°C.

It's comfortable for a long swim from Jun 21 to Oct 29 — about 4.3 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb10Bracing
Mar9Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Bracing

UV index in Nagai 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 Nagai peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar5Moderate
Apr7High
May8Very high
Jun8Very high
Jul9Very high
Aug10Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Moderate

Air quality in Nagai 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 Nagai is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1622 µg/m³Dec 1710 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar21Moderate
Apr22Moderate
May21Moderate
Jun16Moderate
Jul14Moderate
Aug12Moderate
Sep12Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Nagai?

Nagai sits at 38.1°N, 140.0°E, 204 m above sea level, in Japan. The nearest listed city is Nanyō, 10 km away.

Topography around Nagai

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

Within 3 km, the terrain around Nagai has significant variations in elevation — a maximum elevation change of 254 m around an average of 224 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,329 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,110 m.

The land around Nagai is covered by cropland (41%), trees (28%) and artificial surfaces (24%) within 3 km, trees (72%) and cropland (21%) within 16 km, and trees (74%) within 80 km.

3 km
254 m
16 km
1,329 m
80 km
2,110 m
treesgrasslandcroplandartificial surfacesbare terrainwater
January weather nearby: Nanyō 10 km · Takahata 18 km · Kaminoyama 22 km · Yonezawa 23 km · Yamagata 32 km · Sagae 36 km · Tendō 40 km · Yachi 43 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 Nagai (38.1036°, 140.035°, elevation 204 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).