Naoshima weather in September

In September, Naoshima sees average daytime highs of 27°C and overnight lows near 23°C, with 150 mm of rain across 10.2 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 25°C by the end. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels oppressive.

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 Naoshima's 7th-clearest and 8th-windiest month. For the whole year in context, see Naoshima's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
23°
10th coldest
Rainfall
150 mm
10.2 wet days
Daylight
12 h 12 min
5:52 AM – 6:05 PM
Cloud cover
60%
7th clearest
Wind
13 km/h
8th windiest
Solar energy
4.2 kWh/m²
Travel score
6.4
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 28°C in the first days to 25°C by the end.

A typical September day in Naoshima reaches about 27°C in the afternoon and slips back to 23°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 29°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)
12925
22825
32825
42825
52825
62825
72824
82824
92824
102824
112724
122724
132723
142723
152723
162723
172623
182623
192622
202622
212622
222622
232622
242522
252521
262521
272521
282521
292521
302421

How September really feels in Naoshima

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.

Naoshima weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 5810.70.6102.0
Feb10° / 619.60.510.72.2
Mar13° / 9310.4011.73.5
Apr17° / 12°10410.4012.85.3
May21° / 17°1219.6013.86.5
Jun24° / 21°15811014.36.3
Jul28° / 24°15911.2014.15.9
Aug29° / 26°867.1013.35.6
Sep27° / 23°15010.2012.26.4
Oct22° / 18°1268.8011.17.0
Nov17° / 12°607.3010.25.6
Dec12° / 609.90.19.73.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 50%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14951
24852
34951
44951
54951
64951
74951
84951
94951
104852
114951
124951
134951
145050
154951
164951
175050
184951
194951
204951
215050
225050
235050
245050
255149
265149
275149
285149
295248
305248

Chance of precipitation in September

Any precipitation

Naoshima gets around 150 mm of rain over 10.2 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 33% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
132
232
333
433
534
634
734
834
934
1034
1134
1234
1333
1433
1533
1633
1732
1832
1932
2033
2133
2233
2333
2433
2533
2634
2734
2834
2934
3034

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 63% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1019254718
2019264617
30110274616
40211284515
50212284414
60213294313
70314294212
81315304111
91416303910
10141730389
11151830378
12261930358
13272030347
14382130326
15392230306
163102230295
174122330275
185132429254
195142529234
206152628223
216172728203
227182727182
237192827172
248202926152
258212925142
269223025131
2710233124121
2810243123111
2911253222101
301225322191

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 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
112calm
212calm
312light breeze
412light breeze
512light breeze
612light breeze
712light breeze
812light breeze
912light breeze
1012light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze

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 5:41 AM to 6:02 AM, and sunset from 6:26 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:416:26
212.75:426:25
312.75:426:24
412.65:436:22
512.65:446:21
612.65:456:19
712.55:456:18
812.55:466:16
912.55:476:15
1012.45:486:14
1112.45:486:12
1212.45:496:11
1312.35:506:09
1412.35:516:08
1512.25:516:06
1612.25:526:05
1712.25:536:03
1812.15:536:02
1912.15:546:00
2012.15:555:59
2112.05:565:57
2212.05:565:56
2312.05:575:54
2411.95:585:53
2511.95:595:51
2611.85:595:50
2711.86:005:49
2811.86:015:47
2911.76:025:46
3011.76:025:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.2 kWh/m².

For context, solar energy here swings from a low near 2.43 kWh/m² to a high of 5.63 kWh/m² in May across the year — September's 4.2 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.6Bright
44.6Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.2Bright
184.2Bright
194.1Bright
204.1Bright
214.1Bright
224.0Bright
234.0Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Naoshima

In seasonPeak

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

Naoshima 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 Naoshima?

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

6.4
Sightseeing
3rd-best month of the year
6.5
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Naoshima for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Naoshima in September

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

In September, Naoshima sees daytime highs around 27°C and nights near 23°C. Worth packing: light clothes and rain gear. About 10 days see rain.

light clothesrain gear

Sea temperature near Naoshima in September

The nearest coast averages about 27°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 35 km away) is warmest in August at about 28°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 3 to Nov 12 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May18Cool
Jun22Refreshing
Jul25Warm
Aug28Warm
Sep27Warm
Oct23Refreshing
Nov20Cool
Dec16Cool

UV index in Naoshima 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 Naoshima peaks around June 22 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 22UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Naoshima 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 Naoshima is worst in April — around 23 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (October, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1422 µg/m³Oct 1613 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb17Moderate
Mar21Moderate
Apr23Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug15Moderate
Sep13Moderate
Oct12Moderate
Nov13Moderate
Dec13Moderate
Location & terrain

Where is Naoshima?

Naoshima sits at 34.5°N, 134.0°E, 0 m above sea level, in Japan. The nearest listed city is Tamano, 8.0 km away.

Topography around Naoshima

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

Within 3 km, the terrain around Naoshima has only modest variations in elevation — a maximum elevation change of 114 m around an average of 10 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 486 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,946 m.

The land around Naoshima is covered by water (70%) and trees (21%) within 3 km, water (61%) and trees (25%) within 16 km, and trees (56%) and water (30%) within 80 km.

3 km
114 m
16 km
486 m
80 km
1,946 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Tamano 8.0 km · Takamatsu 15 km · Sakaidechō 21 km · Okayama 22 km · Shido 22 km · Utazu 24 km · Hiragi 24 km · Takinomiya 25 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 Naoshima (34.4608°, 133.9972°, elevation 0 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).