Unzen in Fall

In fall (September, October and November), Unzen sees average daytime highs around 24°C and overnight lows near 17°C, with 417 mm of rain over about 29 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.

Over the season highs ease from about 31°C in early September to 16°C by late November. The sky is clear or mostly clear about 41% of the time across fall, and the air most often feels dry.

Fall is Unzen's best season of the year to visit on our travel score. For the whole year in context, see Unzen's year-round climate.

Avg daytime high
24°C
2nd-warmest season
Avg overnight low
17°C
Rainfall
417 mm
29 wet days
Avg wind
9 km/h
Travel score
6.3
best season of the year
Months
Sep · Oct · Nov

Temperature in Unzen in Fall

Average highAverage lowShaded bands: 10–90% of days

Over the season highs ease from about 31°C in early September to 16°C by late November.

A typical fall day in Unzen reaches about 24°C and drops to 17°C overnight. The warmest of the three months is September, the coolest November.

10°20°30°SepOctNov

How fall really feels in Unzen

Once humidity and wind are folded in, fall brings about 10 days that feel above 32°C and 0 that feel at or below 0°C.

Days feeling ≥ 32°C
10
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

Unzen weather by month

How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan11° / 707.710.12.7
Feb12° / 88910.83.2
Mar15° / 13411.611.84.6
Apr20° / 12°15110.912.86.1
May24° / 16°18211.113.76.6
Jun27° / 21°4291714.15.2
Jul30° / 24°34818.513.93.7
Aug32° / 25°17914.513.23.5
Sep29° / 22°20312.412.25.3
Oct24° / 17°1127.911.27.3
Nov18° / 12°1028.410.36.2
Dec13° / 817.69.93.9

Cloud cover in Fall

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time across fall.

0%25%50%75%100%SepOctNov

Chance of precipitation in Fall

Any precipitation

Unzen gets around 417 mm of rain over 29 wet days across fall. The line is the day-by-day chance of measurable precipitation.

0%20%40%60%SepOctNov

Humidity in Fall

DryComfortableHumidMuggyOppressiveMiserable

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

0%25%50%75%100%SepOctNov

Wind in Fall

Winds average 9 km/h across fall.

051015SepOctNov

Sunrise & sunset in Fall

DaylightNight

Daylight runs from about 12 h 42 min in early September to 10 hours by late November. The lit band spans sunrise to sunset each day.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMSepOctNov

Solar energy in Fall

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day across fall, about 3.6 kWh/m².

024SepOctNov
Planning a trip in fall

Hazard calendar for Unzen

In seasonPeak

In fall, Unzen overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

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

Unzen's rainy season runs June–July, 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 fall a good time to visit Unzen?

Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.

6.3
Sightseeing
1st-best month of the year
4.9
Beach & pool
2nd-best month of the year

fall is a reasonable time to visit Unzen for sightseeing.

What to pack for Unzen in Fall

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

In fall, Unzen sees daytime highs around 24°C and nights near 17°C. Pack light clothes. Worth having: rain gear. About 29 days see rain.

light clothesrain gear

Sea temperature near Unzen in Fall

The nearest coast averages about 23°C across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 17 km away) is warmest in August at about 27°C and coldest in February near 14°C.

It's comfortable for a long swim from May 27 to Nov 14 — about 5.7 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr16Cool
May19Cool
Jun22Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov20Cool
Dec17Cool

UV index in Unzen in Fall

LowModerateHighVery highExtreme

Clear-sky midday UV across fall averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Unzen peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highVery highModerateJul 13UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr8Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep10Very high
Oct7High
Nov4Moderate
Dec3Moderate

Air quality in Unzen in Fall

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.

Air quality in Unzen is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (July, 13 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2325 µg/m³Jul 2114 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb20Moderate
Mar25Moderate
Apr25Moderate
May23Moderate
Jun19Moderate
Jul13Moderate
Aug15Moderate
Sep14Moderate
Oct14Moderate
Nov16Moderate
Dec15Moderate
Location & terrain

Where is Unzen?

Unzen sits at 32.8°N, 130.2°E, 546 m above sea level, in Japan. The nearest listed city is Minamishimabara, 11 km away.

Topography around Unzen

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

Within 3 km, the terrain around Unzen has large variations in elevation — a maximum elevation change of 954 m around an average of 559 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,450 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,724 m.

The land around Unzen is covered by trees (96%) within 3 km, water (42%) and trees (37%) within 16 km, and trees (46%) and water (39%) within 80 km.

3 km
954 m
16 km
1,450 m
80 km
1,724 m
treesgrasslandcroplandartificial surfaceswater
Fall weather nearby: Minamishimabara 11 km · Shimabara 11 km · Isahaya 21 km · Nagasu 26 km · Ōyanomachi-noboritate 26 km · Arao 30 km · Ōmura 32 km · Nagasaki 34 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 Unzen (32.7711°, 130.2484°, elevation 546 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.