Nakano weather in September

In September, Nakano sees average daytime highs of 23°C and overnight lows near 15°C, with 182 mm of rain across 17 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 21°C by the end. The sky is clear or mostly clear about 17% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Nakano's 10th-clearest and 9th-windiest month. For the whole year in context, see Nakano's year-round climate.

Daytime high
23°
3rd warmest
Overnight low
15°
10th coldest
Rainfall
182 mm
17 wet days
Daylight
12 h 12 min
5:34 AM – 5:48 PM
Cloud cover
71%
10th clearest
Wind
5 km/h
9th windiest
Solar energy
3.86 kWh/m²
Travel score
5.4
out of 10

Nakano is city in Nagano Prefecture, Japan.

Density
380/km²
people per km²
Founded
1954

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 26°C in the first days to 21°C by the end.

A typical September day in Nakano reaches about 23°C in the afternoon and slips back to 15°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 28°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12618
22618
32617
42517
52517
62517
72517
82517
92517
102416
112416
122416
132416
142416
152315
162315
172315
182315
192214
202214
212214
222214
232213
242113
252113
262113
272113
282112
292012
302012

How September really feels in Nakano

Once humidity and wind are folded in, September 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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Nakano weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°14722.823.49.80.0
Feb / -5°12018.918.510.60.0
Mar / -2°13818.614.811.70.6
Apr13° / 11514.63.512.93.4
May19° / 13314.70.113.95.5
Jun23° / 14°17818.1014.55.2
Jul26° / 18°24321.7014.34.7
Aug27° / 19°16919.6013.44.9
Sep23° / 15°18217012.25.4
Oct17° / 16115.60.111.14.7
Nov11° / 11616.44.6102.3
Dec / -3°13820.4179.50.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 17% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13565
23565
33565
43664
53664
63664
73565
83466
93466
103466
113466
123466
133466
143367
153268
163367
173367
183268
193169
203169
213268
223268
233268
243268
253268
263268
273268
283268
293268
303268

Chance of precipitation in September

Any precipitation

Nakano gets around 182 mm of rain over 17 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 57% and peaks near 64% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
164
264
363
463
563
662
762
861
960
1060
1159
1258
1358
1457
1556
1656
1755
1855
1955
2054
2154
2254
2353
2453
2553
2653
2754
2854
2954
3054

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 32% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
131545361
231646341
341746331
441846311
552046290
662145280
772245260
882444250
992543230
10102642210
11122741200
12132940180
13153039160
14173137150
15193236130
16223234120
17243332100
1827343190
1929342980
2032342770
2135342560
2238342350
2341342140
2443341940
2546341730
2649331630
2751331420
2854321220
2957311110
3058311010

Wind in September

Winds average 5 km/h in September.

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

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 5:22 AM to 5:46 AM, and sunset from 6:11 PM to 5:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:226:11
212.85:226:09
312.75:236:08
412.75:246:06
512.75:256:05
612.65:266:03
712.65:276:02
812.55:276:00
912.55:285:59
1012.55:295:57
1112.45:305:56
1212.45:315:54
1312.45:315:52
1412.35:325:51
1512.35:335:49
1612.25:345:48
1712.25:355:46
1812.25:365:45
1912.15:365:43
2012.15:375:41
2112.05:385:40
2212.05:395:38
2311.95:405:37
2411.95:415:35
2511.95:415:34
2611.85:425:32
2711.85:435:31
2811.75:445:29
2911.75:455:27
3011.75:465:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.86 kWh/m².

For context, solar energy here swings from a low near 2.15 kWh/m² to a high of 5.65 kWh/m² in May across the year — September's 3.86 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.2Bright
54.2Bright
64.2Bright
74.1Bright
84.1Bright
94.0Bright
104.0Bright
114.0Moderate
123.9Moderate
133.9Moderate
143.9Moderate
153.8Moderate
163.8Moderate
173.8Moderate
183.7Moderate
193.7Moderate
203.7Moderate
213.7Moderate
223.6Moderate
233.6Moderate
243.6Moderate
253.6Moderate
263.5Moderate
273.5Moderate
283.5Moderate
293.5Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Nakano

In seasonPeak

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

Nakano 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 September a good time to visit Nakano?

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

5.4
Sightseeing
2nd-best month of the year
4.1
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Nakano for sightseeing.

What to pack for Nakano in September

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

In September, Nakano sees daytime highs around 23°C and nights near 15°C. Pack rain gear. Worth having: light clothes. About 17 days see rain.

rain gearlight clothes

Sea temperature near Nakano in September

The nearest coast averages about 25°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 47 km away) is warmest in August at about 27°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 20 to Nov 1 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec15Cool

UV index in Nakano in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Nakano peaks around August 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 highVery highModerateAug 13UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May9Very high
Jun9Very high
Jul10Very high
Aug10Extreme
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Nakano in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Nakano is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1721 µg/m³Dec 1510 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug13Moderate
Sep12Good
Oct11Good
Nov11Good
Dec10Good
Location & terrain

Where is Nakano?

Nakano sits at 36.8°N, 138.4°E, 380 m above sea level, in Japan. The nearest listed city is Iiyama, 11 km away.

Topography around Nakano

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

Within 3 km, the terrain around Nakano has significant variations in elevation — a maximum elevation change of 376 m around an average of 401 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,851 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,069 m.

The land around Nakano is covered by trees (42%), artificial surfaces (31%) and cropland (22%) within 3 km, trees (74%) within 16 km, and trees (73%) within 80 km.

3 km
376 m
16 km
1,851 m
80 km
3,069 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Iiyama 11 km · Suzaka 12 km · Nagano 20 km · Arai 31 km · Myoko 32 km · Chikuma 35 km · Sakaki 36 km · Ueda 39 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 Nakano (36.75°, 138.3667°, elevation 380 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).