Tomakomai weather in August

In August, Tomakomai sees average daytime highs of 22°C and overnight lows near 18°C, with 197 mm of rain across 14.5 wet days and about 13.7 hours of daylight. It is the 1st-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 22°C through the month. The sky is clear or mostly clear about 17% of the time in August, and the air most often feels humid.

Daylight stretches from about 14 h 24 min at the start of August to 13 h 06 min by month's end. Set against the rest of the year, August is Tomakomai's 11th-clearest and 10th-windiest month. For the whole year in context, see Tomakomai's year-round climate.

Daytime high
22°
1st warmest
Overnight low
18°
12th coldest
Rainfall
197 mm
14.5 wet days
Daylight
13 h 48 min
4:45 AM – 6:30 PM
Cloud cover
71%
11th clearest
Wind
10 km/h
10th windiest
Solar energy
4.31 kWh/m²
Travel score
5.8
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 22°C through the month.

A typical August day in Tomakomai reaches about 22°C in the afternoon and slips back to 18°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 25°C. Set against its neighbours, August runs about 2°C warmer than July and about 2°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12218
22218
32218
42218
52218
62218
72218
82218
92218
102218
112218
122218
132218
142218
152218
162218
172218
182218
192218
202218
212218
222218
232218
242218
252218
262218
272218
282218
292217
302217
312217

How August really feels in Tomakomai

Once humidity and wind are folded in, August averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August 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 August compares with the rest of the year at a glance. August is the 1st-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -7°447.18.89.20.0
Feb-1° / -7°437.3910.30.0
Mar / -4°6310.39.311.60.0
Apr / 7811.53.213.11.1
May13° / 10911.80.114.43.2
Jun16° / 12°10011.3015.14.8
Jul20° / 16°13813.7014.85.6
Aug22° / 18°19714.5013.75.8
Sep20° / 15°17715012.35.4
Oct14° / 11011.80.210.84.0
Nov / 7810.839.60.9
Dec / -4°638.78.68.90.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 17% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 16% of August, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13070
23169
33169
43169
53169
63367
73367
83367
93367
103367
113367
123268
133268
143169
153169
163169
173169
183169
193268
203367
213367
223466
233466
243466
253565
263565
273763
283664
293664
303664
313763

Chance of precipitation in August

Any precipitation

Tomakomai gets around 197 mm of rain over 14.5 wet days in August, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 47% and peaks near 49% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
146
246
346
446
546
646
746
846
947
1047
1147
1248
1348
1448
1549
1649
1749
1849
1948
2048
2148
2248
2348
2447
2547
2647
2748
2848
2948
3048
3149

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the humid band about 37% of days. Sticky, muggy-or-worse air turns up on roughly 43% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
131633426
231532427
331532428
431532428
531531429
631532429
731432419
831432419
9314334010
10314344010
1131335399
1231336399
1331337389
1431337389
1531338378
1631339378
1731440367
1841440357
1941541356
2041541346
2141641346
2241641335
2341741325
2441841325
2541941314
2652041314
2752141304
2852241293
2962340283
3062340273
3172440263

Wind in August

Winds average 10 km/h in August.

Across August, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 24 min at the start of August to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 4:29 AM to 5:02 AM, and sunset from 6:50 PM to 6:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.44:296:50
214.34:306:49
314.34:316:48
414.24:326:47
514.24:336:45
614.24:346:44
714.14:356:43
814.14:366:42
914.04:386:40
1014.04:396:39
1114.04:406:37
1213.94:416:36
1313.94:426:35
1413.84:436:33
1513.84:446:32
1613.84:456:30
1713.74:466:29
1813.74:476:27
1913.64:486:26
2013.64:506:24
2113.54:516:22
2213.54:526:21
2313.44:536:19
2413.44:546:17
2513.34:556:16
2613.34:566:14
2713.34:576:12
2813.24:586:11
2913.25:006:09
3013.15:016:07
3113.15:026:06

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.31 kWh/m².

For context, solar energy here swings from a low near 1.67 kWh/m² to a high of 5.41 kWh/m² in May across the year — August's 4.31 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.2Bright
194.2Bright
204.2Bright
214.2Bright
224.2Bright
234.2Bright
244.2Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.1Bright
304.1Bright
314.1Bright
Planning a trip in August

Hazard calendar for Tomakomai

In seasonPeak

In August, Tomakomai sits inside 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.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Tomakomai?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.8
Sightseeing
1st-best month of the year
4.1
Beach & pool
1st-best month of the year

August is a reasonable time to visit Tomakomai for sightseeing.

What to pack for Tomakomai in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Tomakomai sees daytime highs around 22°C and nights near 18°C. Pack rain gear. Worth having: light clothes. About 15 days see rain.

rain gearlight clothes

Sea temperature near Tomakomai in August

The nearest coast averages about 20°C in August — 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.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan6Bracing
Feb4Bracing
Mar3Bracing
Apr5Bracing
May8Bracing
Jun13Bracing
Jul17Cool
Aug20Refreshing
Sep20Cool
Oct16Cool
Nov13Bracing
Dec10Bracing

UV index in Tomakomai in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 (very high — sun protection essential). 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighVery highHighModerateLowAug 18UV 8Dec 19UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr6High
May7Very high
Jun6High
Jul5Moderate
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Tomakomai in August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August 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).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1119 µg/m³Dec 158 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb14Moderate
Mar19Moderate
Apr19Moderate
May18Moderate
Jun13Moderate
Jul12Good
Aug10Good
Sep9Good
Oct11Good
Nov9Good
Dec8Good
Location & terrain

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.

3 km
58 m
16 km
439 m
80 km
1,859 m
treesgrasslandcroplandartificial surfaceswaterwetland
August weather nearby: Chitose 21 km · Shiraoi 23 km · Eniwa 29 km · Kitahiroshima 38 km · Noboribetsu 40 km · Sapporo 52 km · Ebetsu 53 km · Muroran 62 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
Shintoism 49%Buddhism 46%other 4%Christianity 1%

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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).