Tomakomai weather in May

In May, Tomakomai sees average daytime highs of 13°C and overnight lows near 7°C, with 109 mm of precipitation across 11.8 wet days and about 14.4 hours of daylight. It is the 6th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 11°C in the first days to 14°C by the end. The sky is clear or mostly clear about 26% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 48 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is Tomakomai's 8th-clearest and 9th-windiest month. For the whole year in context, see Tomakomai's year-round climate.

Daytime high
13°
6th warmest
Overnight low
7th coldest
Precipitation
109 mm
11.8 wet days
Daylight
14 h 24 min
4:17 AM – 6:43 PM
Cloud cover
65%
8th clearest
Wind
10 km/h
9th windiest
Solar energy
5.41 kWh/m²
Travel score
3.2
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 11°C in the first days to 14°C by the end.

A typical May day in Tomakomai reaches about 13°C in the afternoon and slips back to 7°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 9°C and 16°C. Set against its neighbours, May runs about 5°C warmer than April and about 4°C cooler than June.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
1104
2105
3115
4115
5115
6115
7115
8116
9116
10126
11126
12126
13126
14127
15127
16137
17137
18137
19138
20138
21138
22138
23148
24148
25149
26149
27149
28149
29149
30149
31159

How May really feels in Tomakomai

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 6th-warmest and 5th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 60%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24357
34357
44357
54159
64060
73961
84060
94060
103961
114060
124060
133961
143961
153961
163961
173961
183961
194060
204060
214060
224060
234060
244159
254159
264060
274060
284060
294159
304060
313961

Chance of precipitation in May

Any precipitationSnow

Tomakomai gets around 109 mm of rain and snow over 11.8 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 38% and peaks near 41% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1402
2402
3402
4402
5401
6411
7411
8411
9411
10411
11411
12411
13401
14401
15391
16390
17380
18380
19370
20370
21360
22360
23360
24350
25350
26360
27360
28360
29360
30360
31360

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
27991
28991
29991
30991
31982

Wind in May

Winds average 10 km/h in May.

Across May, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 48 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over May. Sunrise moves from 4:36 AM to 4:05 AM, and sunset from 6:26 PM to 6:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:366:26
213.94:346:27
313.94:336:28
414.04:326:29
514.04:306:30
614.04:296:32
714.14:286:33
814.14:266:34
914.24:256:35
1014.24:246:36
1114.24:236:37
1214.34:216:38
1314.34:206:39
1414.44:196:40
1514.44:186:42
1614.44:176:43
1714.54:166:44
1814.54:156:45
1914.54:146:46
2014.64:136:47
2114.64:126:48
2214.64:116:49
2314.74:116:50
2414.74:106:51
2514.74:096:52
2614.74:086:53
2714.84:086:53
2814.84:076:54
2914.84:066:55
3014.84:066:56
3114.94:056:57

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.41 kWh/m² — the sunniest month for solar.

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 — May's 5.41 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.4Bright
155.4Bright
165.4Bright
175.4Bright
185.4Bright
195.4Bright
205.4Bright
215.4Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in May

Hazard calendar for Tomakomai

In seasonPeak

In May, 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 May a good time to visit Tomakomai?

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

3.2
Sightseeing
6th-best month of the year
0.0
Beach & pool
6th-best month of the year

May is a weaker month for outdoor sightseeing in Tomakomai.

What to pack for Tomakomai in May

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

In May, Tomakomai sees daytime highs around 13°C and nights near 7°C. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Tomakomai in May

The nearest coast averages about 8°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks 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 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 May

GoodModeratePoorUnhealthyVery unhealthy

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