Okayama in Summer
In summer (June, July and August), Okayama sees average daytime highs around 30°C and overnight lows near 23°C, with 467 mm of rain over about 36 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Over the season highs climb from about 26°C in early June to 32°C by late August. The sky is clear or mostly clear about 21% of the time across summer, and the air most often feels oppressive.
Summer is Okayama's 3rd-best season to visit on our travel score. For the whole year in context, see Okayama's year-round climate.
- Avg daytime high
- 30°C
- warmest season of the year
- Avg overnight low
- 23°C
- Rainfall
- 467 mm
- 36 wet days
- Avg wind
- 8 km/h
- Travel score
- 4.5
- 3rd-best season
- Months
- Jun · Jul · Aug
Temperature in Okayama in Summer
Over the season highs climb from about 26°C in early June to 32°C by late August.
A typical summer day in Okayama reaches about 30°C and drops to 23°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Okayama
Once humidity and wind are folded in, summer brings about 57 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.
Okayama 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 | 10° / 2° | 40 | 5.5 | 0.3 | 9.9 | 2.4 |
| Feb | 11° / 2° | 48 | 6.4 | 0.6 | 10.7 | 2.8 |
| Mar | 14° / 5° | 92 | 9.3 | 0.1 | 11.7 | 4.3 |
| Apr | 20° / 10° | 108 | 9.7 | 0 | 12.8 | 6.2 |
| May | 24° / 15° | 125 | 9.9 | 0 | 13.8 | 6.8 |
| Jun | 27° / 20° | 172 | 12.2 | 0 | 14.3 | 5.8 |
| Jul | 31° / 24° | 187 | 13.6 | 0 | 14.1 | 4.0 |
| Aug | 33° / 25° | 108 | 10.3 | 0 | 13.3 | 3.6 |
| Sep | 29° / 21° | 168 | 10.8 | 0 | 12.2 | 5.5 |
| Oct | 23° / 14° | 114 | 7.7 | 0 | 11.1 | 7.2 |
| Nov | 18° / 8° | 57 | 6.1 | 0 | 10.2 | 6.2 |
| Dec | 12° / 4° | 46 | 5.3 | 0.1 | 9.7 | 3.7 |
Cloud cover in Summer
The sky is clear or mostly clear about 21% of the time across summer.
Chance of precipitation in Summer
Okayama gets around 467 mm of rain over 36 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 8 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 06 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 5.3 kWh/m².
Hazard calendar for Okayama
In summer, Okayama overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Okayama sits in the Pacific typhoon belt; the season peaks July–October.
Okayama's rainy season runs March–October, when most of the year's rain falls.
Is summer a good time to visit Okayama?
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 Okayama for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Okayama in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Okayama sees daytime highs around 30°C and nights near 23°C. Pack light clothes. Worth having: rain gear and sun protection. About 36 days see rain.
Sea temperature near Okayama in Summer
The nearest coast averages about 24°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 41 km away) is warmest in August at about 27°C and coldest in February near 13°C.
It's comfortable for a long swim from Jun 7 to Nov 12 — about 5.2 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 | 17 | 21 | 25 | 27 | 26 | 24 | 20 | 16 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Warm | Warm | Warm | Refreshing | Cool | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 14 | Bracing |
| Feb | 13 | Bracing |
| Mar | 13 | Bracing |
| Apr | 15 | Bracing |
| May | 17 | Cool |
| Jun | 21 | Refreshing |
| Jul | 25 | Warm |
| Aug | 27 | Warm |
| Sep | 26 | Warm |
| Oct | 24 | Refreshing |
| Nov | 20 | Cool |
| Dec | 16 | Cool |
UV index in Okayama 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 Okayama peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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) | 3 | 4 | 5 | 7 | 8 | 10 | 10 | 9 | 9 | 6 | 4 | 2 |
| Level | Moderate | Moderate | High | Very high | Very high | Very high | Extreme | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | High |
| Apr | 7 | Very high |
| May | 8 | Very high |
| Jun | 10 | Very high |
| Jul | 10 | Extreme |
| Aug | 9 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 2 | Moderate |
Air quality in Okayama 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 Okayama is worst in April — around 15 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (October, 8 µg/m³).
Seasonal pattern from CAMS reanalysis, scaled to Okayama's WHO annual average of 11 µg/m³.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 10 | 12 | 14 | 15 | 14 | 12 | 10 | 10 | 9 | 8 | 9 | 9 |
| Level | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 10 | Good |
| Feb | 12 | Good |
| Mar | 14 | Moderate |
| Apr | 15 | Moderate |
| May | 14 | Moderate |
| Jun | 12 | Moderate |
| Jul | 10 | Good |
| Aug | 10 | Good |
| Sep | 9 | Good |
| Oct | 8 | Good |
| Nov | 9 | Good |
| Dec | 9 | Good |
Where is Okayama?
Okayama sits at 34.6°N, 133.9°E, 5 m above sea level, in Japan. The nearest listed city is Tamano, 15 km away.
Topography around Okayama
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Okayama.
Within 3 km, the terrain around Okayama has only modest variations in elevation — a maximum elevation change of 171 m around an average of 13 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 503 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,811 m.
The land around Okayama is covered by artificial surfaces (79%) within 3 km, trees (41%) and artificial surfaces (26%) within 16 km, and trees (61%) and water (26%) 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 Okayama (34.65°, 133.9333°, elevation 5 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.