Tōyō weather in September

In September, Tōyō sees average daytime highs of 27°C and overnight lows near 21°C, with 180 mm of rain across 13.6 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 29°C in the first days to 24°C by the end. The sky is clear or mostly clear about 24% 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 Tōyō's 9th-clearest and 6th-windiest month. For the whole year in context, see Tōyō's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
180 mm
13.6 wet days
Daylight
12 h 12 min
5:28 AM – 5:42 PM
Cloud cover
66%
9th clearest
Wind
12 km/h
6th windiest
Solar energy
3.64 kWh/m²
Travel score
5.6
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 24°C by the end.

A typical September day in Tōyō reaches about 27°C in the afternoon and slips back to 21°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 31°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12924
22923
32923
42923
52923
62923
72923
82823
92822
102822
112822
122822
132822
142722
152721
162721
172721
182621
192620
202620
212620
222620
232520
242519
252519
262519
272519
282419
292419
302418

How September really feels in Tōyō

Once humidity and wind are folded in, September averages 3 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
3
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.

Tōyō 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 / 676.91.29.92.1
Feb10° / 627.51.510.62.4
Mar13° / 11311.60.811.73.7
Apr18° / 10°11311.4012.95.5
May23° / 15°12911.8013.96.4
Jun25° / 19°15913.6014.45.8
Jul29° / 23°14912.9014.24.9
Aug31° / 25°11010.8013.34.5
Sep27° / 21°18013.6012.25.6
Oct21° / 15°20912.9011.16.1
Nov16° / 919.8010.15.3
Dec12° / 597.50.29.63.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% 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 62%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13961
24060
33961
44060
54060
64060
73961
83961
93961
103961
113961
123862
133862
143862
153862
163862
173862
183664
193664
203664
213763
223664
233664
243664
253763
263763
273862
283763
293763
303763

Chance of precipitation in September

Any precipitation

Tōyō gets around 180 mm of rain over 13.6 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 46% and peaks near 47% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
142
242
343
443
543
644
744
844
945
1045
1145
1245
1346
1446
1546
1646
1747
1847
1947
2047
2147
2247
2347
2447
2547
2647
2747
2847
2947
3046

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 30% of days. Sticky, muggy-or-worse air turns up on roughly 65% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1017274915
2017284914
3018294913
4018294813
5029304812
60210304711
71211304610
8131231459
9131331448
10141431428
11141532417
12151632396
13261733376
14261933355
15272033335
16382133314
17392333283
184112432263
194122532242
205132732222
216142831202
226152930181
237173029161
247183228141
258183327121
269193426111
271020352591
281021362480
291121372370
301222372260

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
412calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012calm

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 5:17 AM to 5:40 AM, and sunset from 6:04 PM to 5:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:176:04
212.85:176:03
312.75:186:01
412.75:196:00
512.65:205:58
612.65:215:57
712.65:215:55
812.55:225:54
912.55:235:52
1012.55:245:51
1112.45:255:49
1212.45:255:48
1312.35:265:46
1412.35:275:45
1512.35:285:43
1612.25:285:42
1712.25:295:40
1812.15:305:39
1912.15:315:37
2012.15:325:36
2112.05:325:34
2212.05:335:33
2312.05:345:31
2411.95:355:30
2511.95:365:28
2611.85:365:26
2711.85:375:25
2811.85:385:23
2911.75:395:22
3011.75:405:21

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.64 kWh/m².

For context, solar energy here swings from a low near 2.33 kWh/m² to a high of 5.07 kWh/m² in May across the year — September's 3.64 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.1Bright
34.1Bright
44.1Bright
54.0Bright
64.0Bright
74.0Moderate
83.9Moderate
93.9Moderate
103.8Moderate
113.8Moderate
123.8Moderate
133.7Moderate
143.7Moderate
153.6Moderate
163.6Moderate
173.6Moderate
183.5Moderate
193.5Moderate
203.5Moderate
213.4Moderate
223.4Moderate
233.4Moderate
243.3Moderate
253.3Moderate
263.3Moderate
273.2Moderate
283.2Moderate
293.2Moderate
303.1Moderate
Planning a trip in September

Hazard calendar for Tōyō

In seasonPeak

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

Tōyō 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 Tōyō?

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

5.6
Sightseeing
4th-best month of the year
5.9
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Tōyō for sightseeing.

What to pack for Tōyō in September

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

In September, Tōyō sees daytime highs around 27°C and nights near 21°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Tōyō 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 26°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 7 to Nov 3 — about 4.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun21Refreshing
Jul23Refreshing
Aug26Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Tōyō in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Tōyō peaks around August 10 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 highModerateAug 10UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep8Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Tōyō 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 Tōyō is worst in April — around 26 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1426 µg/m³Dec 1814 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb21Moderate
Mar25Moderate
Apr26Moderate
May24Moderate
Jun20Moderate
Jul17Moderate
Aug16Moderate
Sep16Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Tōyō?

Tōyō sits at 35.7°N, 139.8°E, 15 m above sea level, in Japan. The nearest listed city is Ōjima, 3.0 km away.

Topography around Tōyō

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

Within 3 km, the terrain around Tōyō has only modest variations in elevation — a maximum elevation change of 42 m around an average of 5 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 75 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,832 m.

The land around Tōyō is covered by artificial surfaces (74%) within 3 km, artificial surfaces (65%) and water (28%) within 16 km, and trees (34%), artificial surfaces (26%) and water (22%) within 80 km.

3 km
42 m
16 km
75 m
80 km
1,832 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ōjima 3.0 km · Toyosu 3.0 km · Chūō 4.0 km · Kachidoki 4.0 km · Funabori 5.0 km · Hirai 5.0 km · Akihabara 5.0 km · Taito 5.0 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 Tōyō (35.6698°, 139.8146°, elevation 15 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).