Yachimata in Summer
In summer (June, July and August), Yachimata sees average daytime highs around 28°C and overnight lows near 22°C, with 423 mm of rain over about 39 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Over the season highs climb from about 24°C in early June to 30°C by late August. The sky is clear or mostly clear about 18% of the time across summer, and the air most often feels oppressive.
Summer is Yachimata's 2nd-best season to visit on our travel score. For the whole year in context, see Yachimata's year-round climate.
- Avg daytime high
- 28°C
- warmest season of the year
- Avg overnight low
- 22°C
- Rainfall
- 423 mm
- 39 wet days
- Avg wind
- 11 km/h
- Travel score
- 5.1
- 2nd-best season
- Months
- Jun · Jul · Aug
Temperature in Yachimata in Summer
Over the season highs climb from about 24°C in early June to 30°C by late August.
A typical summer day in Yachimata reaches about 28°C and drops to 22°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Yachimata
Once humidity and wind are folded in, summer brings about 45 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Yachimata weather by month
How the three summer months (June, July and August) 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° / 2° | 75 | 7.6 | 0.8 | 9.9 | 2.1 |
| Feb | 10° / 3° | 71 | 8.4 | 1.1 | 10.7 | 2.3 |
| Mar | 13° / 6° | 125 | 12.8 | 0.5 | 11.7 | 3.5 |
| Apr | 18° / 10° | 113 | 12.6 | 0 | 12.9 | 5.3 |
| May | 22° / 15° | 128 | 11.6 | 0 | 13.9 | 6.3 |
| Jun | 25° / 19° | 159 | 13.7 | 0 | 14.4 | 5.8 |
| Jul | 29° / 23° | 150 | 13.8 | 0 | 14.2 | 4.9 |
| Aug | 30° / 24° | 114 | 11.9 | 0 | 13.3 | 4.5 |
| Sep | 27° / 21° | 175 | 14.3 | 0 | 12.2 | 5.6 |
| Oct | 21° / 16° | 207 | 13 | 0 | 11.1 | 6.1 |
| Nov | 16° / 10° | 102 | 10.4 | 0 | 10.1 | 5.2 |
| Dec | 12° / 5° | 68 | 8.4 | 0.1 | 9.6 | 3.2 |
Cloud cover in Summer
The sky is clear or mostly clear about 18% of the time across summer.
Chance of precipitation in Summer
Yachimata gets around 423 mm of rain over 39 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 12 min in early June to 12 h 48 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.0 kWh/m².
Hazard calendar for Yachimata
In summer, Yachimata overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Yachimata sits in the Pacific typhoon belt; the season peaks July–October.
Is summer a good time to visit Yachimata?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Yachimata for sightseeing.
What to pack for Yachimata in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Yachimata sees daytime highs around 28°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 39 days see rain.
Sea temperature near Yachimata in Summer
The nearest coast averages about 23°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 28 km away) is warmest in August at about 25°C and coldest in February near 15°C.
It's comfortable for a long swim from Jun 5 to Nov 22 — about 5.6 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 15 | 15 | 16 | 19 | 21 | 23 | 25 | 25 | 23 | 21 | 18 |
| Comfort | Cool | Bracing | Cool | Cool | Cool | Refreshing | Refreshing | Warm | Warm | Refreshing | Refreshing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 15 | Bracing |
| Mar | 15 | Cool |
| Apr | 16 | Cool |
| May | 19 | Cool |
| Jun | 21 | Refreshing |
| Jul | 23 | Refreshing |
| Aug | 25 | Warm |
| Sep | 25 | Warm |
| Oct | 23 | Refreshing |
| Nov | 21 | Refreshing |
| Dec | 18 | Cool |
UV index in Yachimata in Summer
Clear-sky midday UV across summer averages 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 Yachimata peaks around August 12 at about 10 (extreme) — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 4 | 7 | 8 | 9 | 10 | 10 | 8 | 6 | 3 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Very high | Very high | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 4 | Moderate |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 10 | Very high |
| Aug | 10 | Extreme |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 3 | Moderate |
| Dec | 2 | Moderate |
Air quality in Yachimata in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Yachimata 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 Yachimata?
Yachimata sits at 35.6°N, 140.3°E, 47 m above sea level, in Japan. The nearest listed city is Ryōgoku, 9.0 km away.
Topography around Yachimata
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Yachimata.
Within 3 km, the terrain around Yachimata has only modest variations in elevation — a maximum elevation change of 57 m around an average of 46 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 114 m; within 80 km, large variations in elevation — a maximum elevation change of 840 m.
The land around Yachimata is covered by trees (38%), artificial surfaces (32%) and cropland (25%) within 3 km, trees (44%), cropland (26%) and artificial surfaces (24%) within 16 km, and water (39%), trees (23%) and artificial surfaces (22%) 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 Yachimata (35.65°, 140.3167°, elevation 47 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.