Ishioka weather in September

In September, Ishioka sees average daytime highs of 26°C and overnight lows near 20°C, with 174 mm of rain across 14.5 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 28°C in the first days to 24°C by the end. The sky is clear or mostly clear about 19% of the time in September, and the air most often feels muggy.

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 Ishioka's 9th-clearest and 6th-windiest month. For the whole year in context, see Ishioka's year-round climate.

Daytime high
26°
3rd warmest
Overnight low
20°
10th coldest
Rainfall
174 mm
14.5 wet days
Daylight
12 h 12 min
5:26 AM – 5:40 PM
Cloud cover
69%
9th clearest
Wind
9 km/h
6th windiest
Solar energy
3.77 kWh/m²
Travel score
5.6
out of 10

Ishioka is city in Ibaraki Prefecture, Japan.

Density
339/km²
people per km²
Founded
1954

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 28°C in the first days to 24°C by the end.

A typical September day in Ishioka reaches about 26°C in the afternoon and slips back to 20°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12923
22922
32922
42822
52822
62822
72822
82822
92822
102721
112721
122721
132721
142721
152720
162620
172620
182620
192620
202519
212519
222519
232519
242519
252418
262418
272418
282418
292418
302418

How September really feels in Ishioka

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.

Ishioka 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 / 616.71.59.81.8
Feb / 617.41.710.62.1
Mar13° / 11012.5111.73.4
Apr18° / 11411.90.112.95.3
May22° / 14°14012.5013.96.2
Jun25° / 18°15314.9014.45.6
Jul29° / 22°17116.1014.24.7
Aug30° / 23°12713.6013.44.5
Sep26° / 20°17414.5012.25.6
Oct21° / 14°19112.4011.16.1
Nov16° / 919.5010.15.1
Dec11° / 607.40.29.62.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23862
33862
43862
53862
63961
73862
83862
93763
103862
113763
123664
133763
143664
153565
163565
173565
183565
193565
203466
213466
223466
233565
243565
253565
263565
273664
283664
293664
303763

Chance of precipitation in September

Any precipitation

Ishioka gets around 174 mm of rain over 14.5 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 50% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
149
249
349
450
550
650
750
850
950
1050
1150
1250
1350
1450
1549
1649
1749
1849
1949
2048
2148
2248
2347
2447
2547
2646
2746
2846
2946
3046

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 30% of days. Sticky, muggy-or-worse air turns up on roughly 59% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10111304710
20112314610
3021232459
4021332449
5021433438
6031433427
7031534417
8041634396
9151734386
10151834375
11161834355
12271934344
13282034324
14392234303
153102333283
164112433262
175122532242
186132632222
197142731192
208152830171
219172929161
2210183028141
2311193127121
2412203226101
251221332491
261321342371
271422352261
281523362151
291623362041
301824371830

Wind in September

Winds average 9 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
119calm
129calm
139calm
149calm
159calm
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 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 5:14 AM to 5:38 AM, and sunset from 6:03 PM to 5:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:146:03
212.85:156:01
312.75:166:00
412.75:175:58
512.75:185:57
612.65:185:55
712.65:195:54
812.55:205:52
912.55:215:51
1012.55:225:49
1112.45:225:48
1212.45:235:46
1312.35:245:45
1412.35:255:43
1512.35:265:42
1612.25:265:40
1712.25:275:38
1812.15:285:37
1912.15:295:35
2012.15:305:34
2112.05:315:32
2212.05:315:31
2312.05:325:29
2411.95:335:28
2511.95:345:26
2611.85:355:25
2711.85:355:23
2811.85:365:22
2911.75:375:20
3011.75:385:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.77 kWh/m².

For context, solar energy here swings from a low near 2.37 kWh/m² to a high of 5.24 kWh/m² in May across the year — September's 3.77 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.2Bright
34.2Bright
44.2Bright
54.1Bright
64.1Bright
74.1Bright
84.0Bright
94.0Bright
104.0Moderate
113.9Moderate
123.9Moderate
133.9Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.7Moderate
193.6Moderate
203.6Moderate
213.5Moderate
223.5Moderate
233.5Moderate
243.4Moderate
253.4Moderate
263.4Moderate
273.4Moderate
283.3Moderate
293.3Moderate
303.3Moderate
Planning a trip in September

Hazard calendar for Ishioka

In seasonPeak

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

Ishioka 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 Ishioka?

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

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

September is a reasonable time to visit Ishioka for sightseeing.

What to pack for Ishioka in September

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

In September, Ishioka sees daytime highs around 26°C and nights near 20°C. Pack rain gear. Worth having: light clothes. About 15 days see rain.

rain gearlight clothes

Sea temperature near Ishioka in September

The nearest coast averages about 23°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 33 km away) is warmest in August at about 24°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 23 to Oct 28 — about 4.2 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun20Cool
Jul22Refreshing
Aug24Warm
Sep23Refreshing
Oct21Refreshing
Nov19Cool
Dec16Cool

UV index in Ishioka 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 Ishioka peaks around August 12 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 highModerateAug 12UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep8Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Ishioka 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 Ishioka is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2425 µg/m³Dec 1914 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar25Moderate
Apr25Moderate
May24Moderate
Jun19Moderate
Jul16Moderate
Aug15Moderate
Sep15Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Ishioka?

Ishioka sits at 36.2°N, 140.3°E, 4 m above sea level, in Japan. The nearest listed city is Suginami, 3.0 km away.

Topography around Ishioka

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

Within 3 km, the terrain around Ishioka has only modest variations in elevation — a maximum elevation change of 43 m around an average of 18 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 863 m; within 80 km, large variations in elevation — a maximum elevation change of 1,031 m.

The land around Ishioka is covered by trees (33%), artificial surfaces (31%) and cropland (28%) within 3 km, trees (49%) and cropland (23%) within 16 km, and trees (32%), water (23%) and cropland (22%) within 80 km.

3 km
43 m
16 km
863 m
80 km
1,031 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Suginami 3.0 km · Kasumigaura 4.0 km · Tsuchiura 11 km · Omitama 13 km · Sakuragawa 15 km · Naka 17 km · Okunoya 17 km · Tsukuba 17 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 Ishioka (36.1833°, 140.2667°, elevation 4 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).