Niigata weather in September

In September, Niigata sees average daytime highs of 25°C and overnight lows near 21°C, with 146 mm of rain across 14.2 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 27°C in the first days to 23°C by the end. The sky is clear or mostly clear about 28% of the time in September, and the air most often feels muggy.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Niigata's 5th-clearest and 8th-windiest month. For the whole year in context, see Niigata's year-round climate.

Daytime high
25°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
146 mm
14.2 wet days
Daylight
12 h 12 min
5:31 AM – 5:45 PM
Cloud cover
64%
5th clearest
Wind
13 km/h
8th windiest
Solar energy
4.06 kWh/m²
Travel score
5.9
out of 10
Air quality
Good
PM2.5 10 µg/m³ · 2010

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 27°C in the first days to 23°C by the end.

A typical September day in Niigata reaches about 25°C in the afternoon and slips back to 21°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 28°C. Set against its neighbours, September runs about 3°C cooler than August and about 5°C warmer than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12723
22723
32723
42723
52723
62623
72623
82622
92622
102622
112622
122622
132522
142522
152521
162521
172521
182521
192421
202420
212420
222420
232420
242320
252319
262319
272319
282319
292319
302219

How September really feels in Niigata

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.

Niigata weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 17726.510.39.70.3
Feb / 11421.28.810.50.4
Mar / 11018.62.511.71.4
Apr13° / 9012.60.2133.5
May18° / 13°9911.80145.6
Jun22° / 18°12311.2014.66.3
Jul26° / 23°22615.2014.45.8
Aug28° / 24°16012.9013.55.7
Sep25° / 21°14614.2012.35.9
Oct20° / 16°15515.80115.4
Nov14° / 10°16419.70.2103.2
Dec / 19525.44.19.41.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 58%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24753
34753
44753
54753
64654
74555
84555
94555
104456
114456
124357
134357
144159
154159
164159
174060
184060
193961
203961
213961
223961
234060
244060
253961
264060
274060
284060
294159
304159

Chance of precipitation in September

Any precipitation

Niigata gets around 146 mm of rain over 14.2 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 49% and peaks near 51% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
149
250
350
450
550
650
751
851
951
1050
1150
1250
1350
1449
1549
1648
1748
1847
1947
2046
2146
2246
2346
2446
2546
2647
2747
2848
2949
3049

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 28% of days. Sticky, muggy-or-worse air turns up on roughly 52% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10113353912
20214353811
30215363710
4021636379
5031736368
6131836357
7141936346
8152136335
9162235325
10172335304
11282434293
12292534273
133102633253
143112732242
154132931222
165143030201
175153129181
186173228161
197183327141
208203425121
219213524110
221022352390
231123362280
241225362060
251326371950
261527371840
271628371630
281728371530
291929361420
302030361220

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
112light breeze
212light breeze
312light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 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 72 minutes over September. Sunrise moves from 5:18 AM to 5:44 AM, and sunset from 6:09 PM to 5:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:186:09
212.85:196:08
312.85:206:06
412.75:206:05
512.75:216:03
612.75:226:01
712.65:236:00
812.65:245:58
912.55:255:57
1012.55:265:55
1112.45:275:53
1212.45:275:52
1312.45:285:50
1412.35:295:49
1512.35:305:47
1612.25:315:45
1712.25:325:44
1812.25:335:42
1912.15:345:40
2012.15:345:39
2112.05:355:37
2212.05:365:36
2311.95:375:34
2411.95:385:32
2511.95:395:31
2611.85:405:29
2711.85:415:28
2811.75:425:26
2911.75:435:24
3011.75:445:23

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.06 kWh/m².

For context, solar energy here swings from a low near 1.62 kWh/m² to a high of 5.68 kWh/m² in May across the year — September's 4.06 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.5Bright
44.5Bright
54.4Bright
64.4Bright
74.3Bright
84.3Bright
94.3Bright
104.2Bright
114.2Bright
124.1Bright
134.1Bright
144.1Bright
154.0Bright
164.0Bright
174.0Moderate
183.9Moderate
193.9Moderate
203.9Moderate
213.8Moderate
223.8Moderate
233.8Moderate
243.8Moderate
253.7Moderate
263.7Moderate
273.7Moderate
283.6Moderate
293.6Moderate
303.6Moderate
Planning a trip in September

Hazard calendar for Niigata

In seasonPeak

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

Niigata 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 Niigata?

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

5.9
Sightseeing
2nd-best month of the year
5.3
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Niigata for sightseeing.

What to pack for Niigata in September

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

In September, Niigata sees daytime highs around 25°C and nights near 21°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Niigata 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 16 km away) is warmest in August at about 26°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 22 to Oct 30 — about 4.3 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan12Bracing
Feb10Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun19Cool
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov18Cool
Dec15Cool

UV index in Niigata in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Niigata peaks around August 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 13UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul9Very high
Aug9Very high
Sep8Very high
Oct5Moderate
Nov3Moderate
Dec2Low

Air quality in Niigata 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 Niigata is worst in April — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 7 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Niigata's WHO annual average of 10 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1216 µg/m³Oct 127 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb10Good
Mar15Moderate
Apr16Moderate
May14Moderate
Jun11Good
Jul9Good
Aug8Good
Sep7Good
Oct7Good
Nov7Good
Dec7Good
Location & terrain

Where is Niigata?

Niigata sits at 37.9°N, 139.0°E, 1 m above sea level, in Japan. The nearest listed city is Kameda-honchō, 8.0 km away.

Topography around Niigata

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

Within 3 km, the terrain around Niigata has only modest variations in elevation — a maximum elevation change of 29 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 42 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,110 m.

The land around Niigata is covered by artificial surfaces (55%) and water (39%) within 3 km, water (52%) and cropland (24%) within 16 km, and water (45%) and trees (44%) within 80 km.

3 km
29 m
16 km
42 m
80 km
2,110 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Kameda-honchō 8.0 km · Niitsu-honchō 15 km · Shirone 18 km · Agano 19 km · Suibara 19 km · Maki 24 km · Gosen 24 km · Shibata 26 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 Niigata (37.9226°, 139.0412°, elevation 1 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).