Otaru in Summer
In summer (June, July and August), Otaru sees average daytime highs around 20°C and overnight lows near 16°C, with 365 mm of rain over about 38 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 15°C in early June to 22°C by late August. The sky is clear or mostly clear about 22% of the time across summer, and the air most often feels dry.
Summer is Otaru's best season of the year to visit on our travel score. For the whole year in context, see Otaru's year-round climate.
- Avg daytime high
- 20°C
- warmest season of the year
- Avg overnight low
- 16°C
- Rainfall
- 365 mm
- 38 wet days
- Avg wind
- 10 km/h
- Travel score
- 5.7
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Otaru in Summer
Over the season highs climb from about 15°C in early June to 22°C by late August.
A typical summer day in Otaru reaches about 20°C and drops to 16°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Otaru
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Otaru 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 | -3° / -6° | 98 | 20.8 | 24.2 | 9.2 | 0.0 |
| Feb | -2° / -6° | 79 | 18 | 20.2 | 10.2 | 0.0 |
| Mar | 2° / -3° | 76 | 15 | 15.4 | 11.6 | 0.0 |
| Apr | 7° / 1° | 66 | 11.2 | 5 | 13.1 | 0.7 |
| May | 12° / 7° | 84 | 11.7 | 0.4 | 14.4 | 3.0 |
| Jun | 17° / 12° | 76 | 10.6 | 0 | 15.1 | 5.1 |
| Jul | 21° / 17° | 127 | 12.8 | 0 | 14.9 | 5.9 |
| Aug | 23° / 19° | 163 | 14.2 | 0 | 13.8 | 6.0 |
| Sep | 20° / 16° | 149 | 13.9 | 0 | 12.3 | 5.6 |
| Oct | 14° / 9° | 117 | 14.9 | 0.6 | 10.8 | 3.5 |
| Nov | 6° / 2° | 129 | 18.6 | 11.2 | 9.5 | 0.7 |
| Dec | -0° / -3° | 126 | 21.9 | 22.5 | 8.9 | 0.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 22% of the time across summer.
Chance of precipitation in Summer
Otaru gets around 365 mm of rain over 38 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 54 min in early June to 13 h 06 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 5.1 kWh/m².
Hazard calendar for Otaru
In summer, Otaru overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Otaru sits in the Pacific typhoon belt; the season peaks July–October.
Is summer a good time to visit Otaru?
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 Otaru for sightseeing.
What to pack for Otaru in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Otaru sees daytime highs around 20°C and nights near 16°C. Pack rain gear. Worth having: light clothes, a warm layer and sun protection. About 38 days see rain.
Sea temperature near Otaru in Summer
The nearest coast averages about 18°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 23 km away) is warmest in August at about 22°C and coldest in February near 6°C.
It's comfortable for a long swim from Jul 31 to Sep 22 — about 1.8 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 7 | 6 | 6 | 7 | 10 | 14 | 19 | 22 | 21 | 17 | 13 | 9 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Refreshing | Cool | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 7 | Bracing |
| Feb | 6 | Bracing |
| Mar | 6 | Bracing |
| Apr | 7 | Bracing |
| May | 10 | Bracing |
| Jun | 14 | Bracing |
| Jul | 19 | Cool |
| Aug | 22 | Refreshing |
| Sep | 21 | Refreshing |
| Oct | 17 | Cool |
| Nov | 13 | Bracing |
| Dec | 9 | Bracing |
UV index in Otaru in Summer
Clear-sky midday UV across summer 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 Otaru peaks around August 18 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 3 | 5 | 7 | 7 | 5 | 8 | 6 | 4 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | Very high | High | Moderate | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 3 | Moderate |
| Apr | 5 | High |
| May | 7 | Very high |
| Jun | 7 | High |
| Jul | 5 | Moderate |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Otaru 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 Otaru is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 9 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) | 11 | 15 | 21 | 21 | 19 | 13 | 12 | 11 | 10 | 12 | 11 | 9 |
| Level | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 15 | Moderate |
| Mar | 21 | Moderate |
| Apr | 21 | Moderate |
| May | 19 | Moderate |
| Jun | 13 | Moderate |
| Jul | 12 | Moderate |
| Aug | 11 | Good |
| Sep | 10 | Good |
| Oct | 12 | Good |
| Nov | 11 | Good |
| Dec | 9 | Good |
Where is Otaru?
Otaru sits at 43.2°N, 141.0°E, 30 m above sea level, in Japan. The nearest listed city is Yoichi, 19 km away.
Topography around Otaru
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Otaru.
Within 3 km, the terrain around Otaru has significant variations in elevation — a maximum elevation change of 508 m around an average of 83 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,289 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,867 m.
The land around Otaru is covered by trees (44%), artificial surfaces (32%) and water (23%) within 3 km, water (49%) and trees (46%) within 16 km, and trees (48%) and water (37%) 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 Otaru (43.1894°, 141.0022°, elevation 30 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.