Yachiyo in Fall
In fall (September, October and November), Yachiyo sees average daytime highs around 21°C and overnight lows near 14°C, with 420 mm of rain over about 35 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 29°C in early September to 14°C by late November. The sky is clear or mostly clear about 32% of the time across fall, and the air most often feels dry.
Fall is Yachiyo's best season of the year to visit on our travel score. For the whole year in context, see Yachiyo's year-round climate.
- Avg daytime high
- 21°C
- 2nd-warmest season
- Avg overnight low
- 14°C
- Rainfall
- 420 mm
- 35 wet days
- Avg wind
- 8 km/h
- Travel score
- 5.6
- best season of the year
- Months
- Sep · Oct · Nov
Temperature in Yachiyo in Fall
Over the season highs ease from about 29°C in early September to 14°C by late November.
A typical fall day in Yachiyo reaches about 21°C and drops to 14°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Yachiyo
Once humidity and wind are folded in, fall brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
fall sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Yachiyo 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.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 9° / -0° | 55 | 6.1 | 1.3 | 9.8 | 1.9 |
| Feb | 10° / 1° | 54 | 6.7 | 1.8 | 10.6 | 2.3 |
| Mar | 13° / 3° | 100 | 11.5 | 0.8 | 11.7 | 3.7 |
| Apr | 18° / 9° | 107 | 11.1 | 0.1 | 12.9 | 5.6 |
| May | 23° / 14° | 134 | 12.5 | 0 | 13.9 | 6.3 |
| Jun | 26° / 18° | 147 | 14.6 | 0 | 14.4 | 5.5 |
| Jul | 30° / 22° | 165 | 15.9 | 0 | 14.2 | 4.4 |
| Aug | 31° / 23° | 123 | 13.7 | 0 | 13.4 | 4.1 |
| Sep | 27° / 20° | 164 | 14.2 | 0 | 12.2 | 5.5 |
| Oct | 21° / 14° | 176 | 12.3 | 0 | 11.1 | 6.2 |
| Nov | 16° / 7° | 80 | 8.7 | 0 | 10.1 | 5.2 |
| Dec | 11° / 2° | 52 | 6.5 | 0.2 | 9.6 | 3.1 |
Cloud cover in Fall
The sky is clear or mostly clear about 32% of the time across fall.
Chance of precipitation in Fall
Yachiyo gets around 420 mm of rain over 35 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 8 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 48 min in early September to 9 h 42 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 3.0 kWh/m².
Hazard calendar for Yachiyo
In fall, Yachiyo overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Yachiyo sits in the Pacific typhoon belt; the season peaks July–October.
Is fall a good time to visit Yachiyo?
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.
fall is a reasonable time to visit Yachiyo for sightseeing.
What to pack for Yachiyo in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Yachiyo sees daytime highs around 21°C and nights near 14°C. Pack rain gear. Worth having: light clothes and a warm layer. About 35 days see rain.
Sea temperature near Yachiyo in Fall
The nearest coast averages about 22°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 62 km away) 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 14 | 13 | 13 | 15 | 18 | 21 | 23 | 26 | 25 | 22 | 19 | 16 |
| Comfort | Bracing | Bracing | Bracing | Cool | Cool | Refreshing | Refreshing | Warm | Warm | Refreshing | Cool | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 14 | Bracing |
| Feb | 13 | Bracing |
| Mar | 13 | Bracing |
| Apr | 15 | Cool |
| May | 18 | Cool |
| Jun | 21 | Refreshing |
| Jul | 23 | Refreshing |
| Aug | 26 | Warm |
| Sep | 25 | Warm |
| Oct | 22 | Refreshing |
| Nov | 19 | Cool |
| Dec | 16 | Cool |
UV index in Yachiyo in Fall
Clear-sky midday UV across fall averages around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Yachiyo peaks around July 21 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 6 | 3 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 10 | Very high |
| Aug | 10 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Moderate |
Air quality in Yachiyo in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Yachiyo 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 15 | 18 | 25 | 25 | 24 | 19 | 16 | 15 | 15 | 16 | 16 | 14 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 15 | Moderate |
| Feb | 18 | Moderate |
| Mar | 25 | Moderate |
| Apr | 25 | Moderate |
| May | 24 | Moderate |
| Jun | 19 | Moderate |
| Jul | 16 | Moderate |
| Aug | 15 | Moderate |
| Sep | 15 | Moderate |
| Oct | 16 | Moderate |
| Nov | 16 | Moderate |
| Dec | 14 | Moderate |
Where is Yachiyo?
Yachiyo sits at 36.2°N, 139.9°E, 20 m above sea level, in Japan. The nearest listed city is Shimo-tsuma, 7.0 km away.
Topography around Yachiyo
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Yachiyo.
Within 3 km, the terrain around Yachiyo has only modest variations in elevation — a maximum elevation change of 32 m around an average of 25 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 53 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,458 m.
The land around Yachiyo is covered by cropland (61%) and artificial surfaces (23%) within 3 km, cropland (49%) and artificial surfaces (28%) within 16 km, and trees (41%), artificial surfaces (27%) and cropland (21%) within 80 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
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 Yachiyo (36.1823°, 139.891°, elevation 20 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.