Itoshima weather in September

In September, Itoshima sees average daytime highs of 27°C and overnight lows near 22°C, with 180 mm of rain across 13 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 29°C in the first days to 26°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 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Itoshima's 3rd-clearest and 8th-windiest month. For the whole year in context, see Itoshima's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
22°
10th coldest
Rainfall
180 mm
13 wet days
Daylight
12 h 12 min
6:07 AM – 6:20 PM
Cloud cover
60%
3rd clearest
Wind
10 km/h
8th windiest
Solar energy
4.19 kWh/m²
Travel score
5.8
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 29°C in the first days to 26°C by the end.

A typical September day in Itoshima reaches about 27°C in the afternoon and slips back to 22°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 30°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)
12924
22924
32924
42924
52924
62924
72924
82923
92823
102823
112823
122823
132823
142822
152822
162722
172722
182722
192722
202721
212721
222721
232621
242621
252621
262620
272620
282620
292520
302520

How September really feels in Itoshima

Once humidity and wind are folded in, September averages 4 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
4
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Itoshima 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
Jan10° / 6410.11.3102.1
Feb11° / 699.60.910.82.4
Mar14° / 112110.111.73.8
Apr18° / 12°12610.4012.85.7
May23° / 16°14110013.76.6
Jun26° / 21°27814.9014.25.7
Jul29° / 25°26216.60144.4
Aug31° / 26°16315013.24.1
Sep27° / 22°18013012.25.8
Oct23° / 17°1017.7011.27.2
Nov17° / 12°888.9010.35.7
Dec12° / 729.90.39.83.3

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 16% of September, with mostly cloudy or overcast conditions the remaining 50%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24753
34753
44852
54951
64852
74951
84951
94951
105050
115050
125149
135149
145149
155149
165149
175050
185050
195050
205050
215050
225050
235050
245050
255149
265050
275050
285248
295248
305248

Chance of precipitation in September

Any precipitation

Itoshima gets around 180 mm of rain over 13 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 42% and peaks near 50% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
150
250
349
449
549
648
748
848
947
1047
1146
1245
1345
1444
1543
1642
1741
1841
1940
2039
2139
2238
2337
2437
2536
2636
2735
2834
2934
3033

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 34% of days. Sticky, muggy-or-worse air turns up on roughly 72% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1003215521
2003225520
3014245318
4015255217
5016265116
6017285015
7017294914
8019304813
90210304612
100211314511
110212324310
121313324110
13141532399
14151633379
15151733358
16261833347
17272033327
18282133306
19292232286
203102432265
213112532245
223132631225
234142731204
244152831194
254162930173
265172930163
275193029143
286203028133
297213027122
308233026112

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 42 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 60 minutes over September. Sunrise moves from 5:57 AM to 6:17 AM, and sunset from 6:41 PM to 6:00 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:576:41
212.75:586:40
312.75:586:38
412.65:596:37
512.66:006:35
612.66:016:34
712.56:016:33
812.56:026:31
912.56:036:30
1012.46:036:28
1112.46:046:27
1212.36:056:25
1312.36:056:24
1412.36:066:23
1512.26:076:21
1612.26:076:20
1712.26:086:18
1812.16:096:17
1912.16:106:15
2012.16:106:14
2112.06:116:13
2212.06:126:11
2312.06:126:10
2411.96:136:08
2511.96:146:07
2611.86:146:05
2711.86:156:04
2811.86:166:03
2911.76:176:01
3011.76:176:00

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.19 kWh/m².

For context, solar energy here swings from a low near 2.14 kWh/m² to a high of 5.37 kWh/m² in May across the year — September's 4.19 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.4Bright
54.4Bright
64.4Bright
74.4Bright
84.4Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.1Bright
214.1Bright
224.1Bright
234.1Bright
244.0Bright
254.0Bright
264.0Moderate
274.0Moderate
284.0Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Itoshima

In seasonPeak

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

Itoshima sits in the Pacific typhoon belt; the season peaks July–October.

Itoshima's rainy season runs April–September, when most of the year's rain falls.

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

Is September a good time to visit Itoshima?

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

5.8
Sightseeing
3rd-best month of the year
6.2
Beach & pool
1st-best month of the year

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

What to pack for Itoshima in September

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

In September, Itoshima sees daytime highs around 27°C and nights near 22°C. Pack light clothes. Worth having: rain gear. About 13 days see rain.

light clothesrain gear

Sea temperature near Itoshima 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 offshore is warmest in August at about 27°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 9 to Nov 20 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb14Bracing
Mar14Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul24Warm
Aug27Warm
Sep25Warm
Oct23Refreshing
Nov20Refreshing
Dec18Cool

UV index in Itoshima 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 Itoshima peaks around July 23 at about 9 (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 highModerateJul 23UV 9Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr8Very high
May8Very high
Jun7Very high
Jul9Very high
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Itoshima 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 Itoshima is worst in April — around 25 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1225 µg/m³Oct 1212 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb20Moderate
Mar25Moderate
Apr25Moderate
May23Moderate
Jun18Moderate
Jul13Moderate
Aug15Moderate
Sep13Moderate
Oct12Moderate
Nov15Moderate
Dec14Moderate
Location & terrain

Where is Itoshima?

Itoshima sits at 33.5°N, 130.2°E, 77 m above sea level, in Japan. The nearest listed city is Maebaru-chūō, 2.0 km away.

Topography around Itoshima

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

Within 3 km, the terrain around Itoshima has only modest variations in elevation — a maximum elevation change of 163 m around an average of 22 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 970 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,212 m.

The land around Itoshima is covered by trees (34%), cropland (26%) and artificial surfaces (25%) within 3 km, trees (46%) and water (37%) within 16 km, and water (51%) and trees (34%) within 80 km.

3 km
163 m
16 km
970 m
80 km
1,212 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Maebaru-chūō 2.0 km · Katanawa 22 km · Fukuoka 22 km · Karatsu 23 km · Kasuga 26 km · Ōnojō 27 km · Shime 28 km · Ishinari 29 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 Itoshima (33.5423°, 130.1842°, elevation 77 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).