Nakanojō weather in September

In September, Nakanojō sees average daytime highs of 22°C and overnight lows near 15°C, with 215 mm of rain across 19.7 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 20°C by the end. The sky is clear or mostly clear about 15% 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 Nakanojō's 10th-clearest and 9th-windiest month. For the whole year in context, see Nakanojō's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
15°
10th coldest
Rainfall
215 mm
19.7 wet days
Daylight
12 h 12 min
5:32 AM – 5:46 PM
Cloud cover
73%
10th clearest
Wind
5 km/h
9th windiest
Solar energy
3.79 kWh/m²
Travel score
4.9
out of 10

Nakanojō is town in Agatsuma District, Gunma Prefecture, Japan.

Density
35/km²
people per km²
Founded
1889

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 24°C in the first days to 20°C by the end.

A typical September day in Nakanojō reaches about 22°C in the afternoon and slips back to 15°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 26°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)
12518
22418
32418
42418
52417
62417
72417
82417
92317
102317
112317
122316
132316
142316
152216
162215
172215
182215
192115
202115
212114
222114
232114
242014
252013
262013
272013
282013
291913
301912

How September really feels in Nakanojō

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.

Nakanojō weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°7814.616.49.80.0
Feb / -5°7413.51410.60.0
Mar / -2°11515.611.811.70.8
Apr13° / 121153.412.93.2
May18° / 10°16016.80.313.94.9
Jun21° / 14°22722014.54.4
Jul25° / 18°27324.2014.24.4
Aug26° / 19°21623.5013.44.6
Sep22° / 15°21519.7012.24.9
Oct16° / 17815.60.211.14.5
Nov11° / 7811.63.5102.5
Dec / -2°6713.512.49.50.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 69%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12971
22971
33070
43070
53070
63169
73169
83070
92971
102971
112971
123070
133070
143070
153070
163169
173169
183070
193070
203070
213169
223169
233268
243268
253268
263268
273268
283466
293466
303466

Chance of precipitation in September

Any precipitation

Nakanojō gets around 215 mm of rain over 19.7 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 66% and peaks near 75% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
175
275
374
474
573
673
772
871
971
1070
1169
1268
1368
1467
1566
1665
1765
1864
1963
2063
2162
2261
2361
2460
2560
2660
2759
2859
2959
3059

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 31% of days. Sticky, muggy-or-worse air turns up on roughly 18% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
121343402
221443391
331544371
431644361
541744341
651843331
761943311
872142291
982242280
1092441260
11102540240
12122639220
13142838210
14152937190
15173035170
16203133150
17223332140
18243430120
19273528100
2029352690
2132362480
2235362370
2337362160
2440371950
2543371740
2645361530
2748361430
2850361220
2952351120
3055341010

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 6 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
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:20 AM to 5:44 AM, and sunset from 6:09 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:206:09
212.85:216:07
312.75:216:06
412.75:226:04
512.75:236:03
612.65:246:01
712.65:256:00
812.55:265:58
912.55:265:57
1012.55:275:55
1112.45:285:54
1212.45:295:52
1312.35:305:51
1412.35:305:49
1512.35:315:47
1612.25:325:46
1712.25:335:44
1812.15:345:43
1912.15:355:41
2012.15:355:40
2112.05:365:38
2212.05:375:36
2312.05:385:35
2411.95:395:33
2511.95:405:32
2611.85:405:30
2711.85:415:29
2811.85:425:27
2911.75:435:26
3011.75:445:24

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.79 kWh/m².

For context, solar energy here swings from a low near 2.38 kWh/m² to a high of 5.53 kWh/m² in May across the year — September's 3.79 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.2Bright
44.1Bright
54.1Bright
64.1Bright
74.0Bright
84.0Moderate
94.0Moderate
103.9Moderate
113.9Moderate
123.9Moderate
133.8Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.7Moderate
193.6Moderate
203.6Moderate
213.6Moderate
223.6Moderate
233.5Moderate
243.5Moderate
253.5Moderate
263.5Moderate
273.4Moderate
283.4Moderate
293.4Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Nakanojō

In seasonPeak

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

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

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

Is September a good time to visit Nakanojō?

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

4.9
Sightseeing
1st-best month of the year
3.4
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Nakanojō for sightseeing.

What to pack for Nakanojō in September

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

In September, Nakanojō sees daytime highs around 22°C and nights near 15°C. Pack rain gear. Worth having: light clothes. About 20 days see rain.

rain gearlight clothes

UV index in Nakanojō 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 Nakanojō peaks around July 18 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 18UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Nakanojō 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 Nakanojō is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1821 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug13Moderate
Sep12Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Nakanojō?

Nakanojō sits at 36.6°N, 138.8°E, 371 m above sea level, in Japan. The nearest listed city is Minakami, 17 km away.

Topography around Nakanojō

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

Within 3 km, the terrain around Nakanojō has significant variations in elevation — a maximum elevation change of 454 m around an average of 421 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,443 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,852 m.

The land around Nakanojō is covered by trees (61%) within 3 km, trees (89%) within 16 km, and trees (81%) within 80 km.

3 km
454 m
16 km
1,443 m
80 km
2,852 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Minakami 17 km · Shibukawa 18 km · Numata 19 km · Ogura 20 km · Kanekomachi 24 km · Annaka 29 km · Maebashi 30 km · Karuizawa 32 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 Nakanojō (36.5872°, 138.8408°, elevation 371 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. 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).