Tomakomai in Summer
In summer (June, July and August), Tomakomai sees average daytime highs around 20°C and overnight lows near 15°C, with 434 mm of rain over about 40 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 15°C in early June to 22°C by late August. The sky is clear or mostly clear about 17% of the time across summer, and the air most often feels dry.
Summer is Tomakomai's best season of the year to visit on our travel score. For the whole year in context, see Tomakomai's year-round climate.
- Avg daytime high
- 20°C
- warmest season of the year
- Avg overnight low
- 15°C
- Rainfall
- 434 mm
- 40 wet days
- Avg wind
- 9 km/h
- Travel score
- 5.4
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Tomakomai 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 Tomakomai reaches about 20°C and drops to 15°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Tomakomai
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.
Tomakomai 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 | -2° / -7° | 44 | 7.1 | 8.8 | 9.2 | 0.0 |
| Feb | -1° / -7° | 43 | 7.3 | 9 | 10.3 | 0.0 |
| Mar | 2° / -4° | 63 | 10.3 | 9.3 | 11.6 | 0.0 |
| Apr | 7° / 2° | 78 | 11.5 | 3.2 | 13.1 | 1.1 |
| May | 13° / 7° | 109 | 11.8 | 0.1 | 14.4 | 3.2 |
| Jun | 16° / 12° | 100 | 11.3 | 0 | 15.1 | 4.8 |
| Jul | 20° / 16° | 138 | 13.7 | 0 | 14.8 | 5.6 |
| Aug | 22° / 18° | 197 | 14.5 | 0 | 13.7 | 5.8 |
| Sep | 20° / 15° | 177 | 15 | 0 | 12.3 | 5.4 |
| Oct | 14° / 8° | 110 | 11.8 | 0.2 | 10.8 | 4.0 |
| Nov | 7° / 2° | 78 | 10.8 | 3 | 9.6 | 0.9 |
| Dec | 1° / -4° | 63 | 8.7 | 8.6 | 8.9 | 0.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 17% of the time across summer.
Chance of precipitation in Summer
Tomakomai gets around 434 mm of rain over 40 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 9 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 4.8 kWh/m².
Hazard calendar for Tomakomai
In summer, Tomakomai overlaps its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Tomakomai sits in the Pacific typhoon belt; the season peaks July–October.
Tomakomai's rainy season runs May–October, when most of the year's rain falls.
Is summer a good time to visit Tomakomai?
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 Tomakomai for sightseeing.
What to pack for Tomakomai in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Tomakomai sees daytime highs around 20°C and nights near 15°C. Pack rain gear. Worth having: light clothes, a warm layer and sun protection. About 40 days see rain.
Sea temperature near Tomakomai in Summer
The nearest coast averages about 17°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 20°C and coldest in March near 3°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 6 | 4 | 3 | 5 | 8 | 13 | 17 | 20 | 20 | 16 | 13 | 10 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Cool | Cool | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 6 | Bracing |
| Feb | 4 | Bracing |
| Mar | 3 | Bracing |
| Apr | 5 | Bracing |
| May | 8 | Bracing |
| Jun | 13 | Bracing |
| Jul | 17 | Cool |
| Aug | 20 | Refreshing |
| Sep | 20 | Cool |
| Oct | 16 | Cool |
| Nov | 13 | Bracing |
| Dec | 10 | Bracing |
UV index in Tomakomai in Summer
Clear-sky midday UV across summer 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 Tomakomai peaks around August 18 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 19 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 | 6 | 7 | 6 | 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 | 6 | High |
| May | 7 | Very high |
| Jun | 6 | High |
| Jul | 5 | Moderate |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Tomakomai 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 Tomakomai is worst in April — around 19 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 8 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) | 10 | 14 | 19 | 19 | 18 | 13 | 12 | 10 | 9 | 11 | 9 | 8 |
| Level | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 10 | Good |
| Feb | 14 | Moderate |
| Mar | 19 | Moderate |
| Apr | 19 | Moderate |
| May | 18 | Moderate |
| Jun | 13 | Moderate |
| Jul | 12 | Good |
| Aug | 10 | Good |
| Sep | 9 | Good |
| Oct | 11 | Good |
| Nov | 9 | Good |
| Dec | 8 | Good |
Where is Tomakomai?
Tomakomai sits at 42.6°N, 141.6°E, 7 m above sea level, in Japan. The nearest listed city is Chitose, 21 km away.
Topography around Tomakomai
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Tomakomai.
Within 3 km, the terrain around Tomakomai has only modest variations in elevation — a maximum elevation change of 58 m around an average of 9 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 439 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,859 m.
The land around Tomakomai is covered by artificial surfaces (47%) and water (31%) within 3 km, water (42%) and trees (41%) within 16 km, and trees (51%) and water (33%) 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 Tomakomai (42.6369°, 141.6033°, elevation 7 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.