Shirahama weather in September

In September, Shirahama sees average daytime highs of 26°C and overnight lows near 23°C, with 215 mm of rain across 13.3 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 27°C in the first days to 25°C by the end. The sky is clear or mostly clear about 35% 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 Shirahama's 9th-clearest and 8th-windiest month. For the whole year in context, see Shirahama's year-round climate.

Daytime high
26°
3rd warmest
Overnight low
23°
10th coldest
Rainfall
215 mm
13.3 wet days
Daylight
12 h 12 min
5:47 AM – 5:59 PM
Cloud cover
58%
9th clearest
Wind
16 km/h
8th windiest
Solar energy
4.42 kWh/m²
Travel score
6.1
out of 10

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 25°C by the end.

A typical September day in Shirahama reaches about 26°C in the afternoon and slips back to 23°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 28°C. Set against its neighbours, September runs about 2°C cooler than August and about 4°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12825
22825
32825
42724
52724
62724
72724
82724
92724
102724
112724
122724
132723
142623
152623
162623
172623
182623
192623
202622
212622
222522
232522
242522
252522
262522
272521
282521
292421
302421

How September really feels in Shirahama

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.

Shirahama weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan10° / 9511.60.5102.3
Feb11° / 10411.10.510.72.4
Mar13° / 15112.3011.73.7
Apr17° / 13°15811.1012.85.4
May21° / 17°17711013.76.2
Jun24° / 21°29315.4014.25.6
Jul27° / 24°24614.40145.7
Aug28° / 25°14613.3013.35.6
Sep26° / 23°21513.3012.26.1
Oct22° / 18°21711.2011.26.6
Nov17° / 14°1278.8010.35.8
Dec13° / 9710.10.19.83.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% 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 50%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15347
25347
35248
45248
55149
65050
75050
85050
95050
104951
114951
124951
134951
144951
154951
164951
174951
184852
194852
204753
214852
224852
234852
244951
254951
264951
275050
284951
295050
305149

Chance of precipitation in September

Any precipitation

Shirahama gets around 215 mm of rain over 13.3 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 44% and peaks near 48% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
148
248
348
448
548
648
748
848
947
1047
1146
1245
1344
1444
1543
1642
1742
1841
1941
2041
2141
2241
2341
2441
2541
2641
2741
2841
2941
3041

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 36% of days. Sticky, muggy-or-worse air turns up on roughly 74% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1004205422
2004215421
3004225420
4015235219
5015245218
6016255117
7016275016
8027284915
9028294813
10129294712
111310304511
121311314410
13131331429
14141431418
15241632397
16251732376
17361931356
18362032345
19372232324
20482332304
21492532283
22592632263
235102731242
246112831222
256122931202
267133030191
277133130171
288143230161
298153229141
309163329131

Wind in September

Winds average 16 km/h in September.

Across September, daily wind ranges from about 15 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze

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 5:36 AM to 5:57 AM, and sunset from 6:20 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:366:20
212.75:376:19
312.75:386:18
412.65:386:16
512.65:396:15
612.65:406:13
712.55:406:12
812.55:416:11
912.55:426:09
1012.45:436:08
1112.45:436:06
1212.35:446:05
1312.35:456:03
1412.35:456:02
1512.25:466:01
1612.25:475:59
1712.25:475:58
1812.15:485:56
1912.15:495:55
2012.15:505:53
2112.05:505:52
2212.05:515:50
2312.05:525:49
2411.95:525:48
2511.95:535:46
2611.85:545:45
2711.85:555:43
2811.85:555:42
2911.75:565:40
3011.75:575:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.42 kWh/m².

For context, solar energy here swings from a low near 2.44 kWh/m² to a high of 5.6 kWh/m² in May across the year — September's 4.42 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
34.9Bright
44.9Bright
54.9Bright
64.8Bright
74.8Bright
84.7Bright
94.7Bright
104.7Bright
114.6Bright
124.6Bright
134.5Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.3Bright
194.3Bright
204.3Bright
214.2Bright
224.2Bright
234.2Bright
244.1Bright
254.1Bright
264.0Bright
274.0Bright
284.0Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Shirahama

In seasonPeak

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

Shirahama 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 Shirahama?

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

6.1
Sightseeing
3rd-best month of the year
5.9
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Shirahama for sightseeing.

What to pack for Shirahama in September

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

In September, Shirahama sees daytime highs around 26°C and nights near 23°C. Worth packing: light clothes and rain gear. About 13 days see rain.

light clothesrain gear

Sea temperature near Shirahama 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 offshore is warmest in August at about 28°C and coldest in February near 17°C.

It's comfortable for a long swim from May 4 to Dec 22 — about 7.7 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan18Cool
Feb17Cool
Mar18Cool
Apr19Cool
May21Refreshing
Jun23Refreshing
Jul26Warm
Aug28Warm
Sep27Warm
Oct25Warm
Nov23Refreshing
Dec20Refreshing

UV index in Shirahama in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Shirahama peaks around July 11 at about 11 (extreme) — 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 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJul 11UV 11Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug9Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Shirahama 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 Shirahama is worst in April — around 19 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1319 µg/m³Dec 1310 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb15Moderate
Mar19Moderate
Apr19Moderate
May17Moderate
Jun14Moderate
Jul10Good
Aug10Good
Sep10Good
Oct10Good
Nov11Good
Dec10Good
Location & terrain

Where is Shirahama?

Shirahama sits at 33.7°N, 135.3°E, 13 m above sea level, in Japan. The nearest listed city is Tanabe, 6.0 km away.

Topography around Shirahama

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

Within 3 km, the terrain around Shirahama has only modest variations in elevation — a maximum elevation change of 148 m around an average of 22 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 789 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,877 m.

The land around Shirahama is covered by water (57%) and trees (26%) within 3 km, water (53%) and trees (41%) within 16 km, and water (54%) and trees (43%) within 80 km.

3 km
148 m
16 km
789 m
80 km
1,877 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Tanabe 6.0 km · Asso 6.0 km · Gobō 28 km · Itogawa 39 km · Kushimoto 46 km · Arida 49 km · Kainan 54 km · Shingū 59 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 Shirahama (33.6833°, 135.35°, elevation 13 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).