Karuizawa weather in June

In June, Karuizawa sees average daytime highs of 21°C and overnight lows near 15°C, with 254 mm of rain across 22.7 wet days and about 14.4 hours of daylight. It is the 4th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 20°C in the first days to 23°C by the end. The sky is clear or mostly clear about 9% of the time in June, and the air most often feels comfortable.

Daylight stretches from about 14 h 18 min at the start of June to 14 h 30 min by month's end. Set against the rest of the year, June is Karuizawa's 12th-clearest and 10th-windiest month. For the whole year in context, see Karuizawa's year-round climate.

Daytime high
21°
4th warmest
Overnight low
15°
9th coldest
Rainfall
254 mm
22.7 wet days
Daylight
14 h 30 min
4:32 AM – 7:00 PM
Cloud cover
80%
12th clearest
Wind
5 km/h
10th windiest
Solar energy
4.84 kWh/m²
Travel score
4.3
out of 10

Temperature in June

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 20°C in the first days to 23°C by the end.

A typical June day in Karuizawa reaches about 21°C in the afternoon and slips back to 15°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 26°C. Set against its neighbours, June runs about 3°C warmer than May and about 4°C cooler than July.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12012
22012
32013
42013
52013
62013
72013
82113
92114
102114
112114
122114
132114
142114
152115
162115
172115
182115
192215
202215
212215
222216
232216
242216
252316
262316
272316
282317
292317
302317

How June really feels in Karuizawa

Once humidity and wind are folded in, June 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

June sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Karuizawa weather by month

How June compares with the rest of the year at a glance. June is the 4th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°597.46.59.80.0
Feb / -4°608.66.710.60.0
Mar / -1°11013.17.111.71.3
Apr14° / 12213.82.112.93.7
May19° / 10°16516.80.113.95.1
Jun21° / 15°25422.7014.44.3
Jul25° / 19°28224014.24.5
Aug26° / 19°24024.1013.44.5
Sep22° / 16°24120.6012.24.8
Oct17° / 19515.5011.14.7
Nov11° / 728.80.610.13.1
Dec / -1°497.64.49.60.6

Cloud cover in June

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 9% of the time in June, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 9% of June, with mostly cloudy or overcast conditions the remaining 81%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12971
22872
32773
42674
52575
62575
72575
82278
92278
102179
112080
122080
131882
141882
151783
161783
171684
181486
191486
201486
211486
221486
231486
241486
251486
261486
271486
281486
291486
301486

Chance of precipitation in June

Any precipitation

Karuizawa gets around 254 mm of rain over 22.7 wet days in June. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 76% and peaks near 81% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
163
265
366
467
568
670
771
872
973
1074
1175
1276
1377
1478
1579
1679
1780
1880
1980
2080
2180
2280
2380
2480
2580
2680
2781
2881
2981
3081

Humidity in June

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, June lands in the comfortable band about 37% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1752320
2722530
3692830
4663040
5633250
6603460
7563671
8533881
9504091
104742111
114343131
124044151
133745171
143446191
153146211
162946242
172646262
182445282
192244303
202043334
211942355
221740376
231538407
241437428
251235449
2611334611
2710314712
289294914
298275015
307255117

Wind in June

Winds average 5 km/h in June.

Across June, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in June

DaylightNight

Daylight runs from about 14 h 18 min at the start of June to 14 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over June. Sunrise moves from 4:34 AM to 4:35 AM, and sunset from 6:52 PM to 7:02 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
114.34:346:52
214.34:346:52
314.34:346:53
414.34:336:54
514.44:336:54
614.44:336:55
714.44:336:55
814.44:326:56
914.44:326:56
1014.44:326:57
1114.44:326:57
1214.44:326:58
1314.44:326:58
1414.54:326:59
1514.54:326:59
1614.54:327:00
1714.54:327:00
1814.54:327:00
1914.54:327:01
2014.54:327:01
2114.54:327:01
2214.54:337:01
2314.54:337:02
2414.54:337:02
2514.54:337:02
2614.54:347:02
2714.54:347:02
2814.54:347:02
2914.54:357:02
3014.54:357:02

Solar energy in June

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in June, about 4.84 kWh/m².

For context, solar energy here swings from a low near 2.51 kWh/m² to a high of 5.52 kWh/m² in May across the year — June's 4.84 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.3Bright
45.3Bright
55.3Bright
65.2Bright
75.2Bright
85.1Bright
95.0Bright
105.0Bright
115.0Bright
124.9Bright
134.9Bright
144.8Bright
154.8Bright
164.7Bright
174.7Bright
184.7Bright
194.6Bright
204.6Bright
214.6Bright
224.5Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
Planning a trip in June

Hazard calendar for Karuizawa

In seasonPeak

In June, Karuizawa sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Karuizawa's rainy season runs May–October, when most of the year's rain falls.

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

Is June a good time to visit Karuizawa?

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

4.3
Sightseeing
6th-best month of the year
2.8
Beach & pool
4th-best month of the year

June is a reasonable time to visit Karuizawa for sightseeing.

What to pack for Karuizawa in June

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

In June, Karuizawa sees daytime highs around 21°C and nights near 15°C. Pack rain gear. Worth having: sun protection. About 23 days see rain.

rain gearsun protection

UV index in Karuizawa in June

LowModerateHighVery highExtreme

Clear-sky midday UV in June peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Karuizawa peaks around July 18 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 18UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Karuizawa in June

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where June falls, not just the annual average.

Air quality in Karuizawa is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1821 µg/m³Dec 1810 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug14Moderate
Sep13Moderate
Oct12Moderate
Nov11Good
Dec10Good
Location & terrain

Where is Karuizawa?

Karuizawa sits at 36.4°N, 138.6°E, 952 m above sea level, in Japan. The nearest listed city is Miyota, 11 km away.

Topography around Karuizawa

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Karuizawa.

Within 3 km, the terrain around Karuizawa has large variations in elevation — a maximum elevation change of 632 m around an average of 1,004 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,316 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,985 m.

The land around Karuizawa is covered by trees (86%) within 3 km, trees (86%) within 16 km, and trees (80%) within 80 km.

3 km
632 m
16 km
2,316 m
80 km
2,985 m
treesgrasslandcroplandartificial surfacesbare terrainwater
June weather nearby: Miyota 11 km · Komoro 18 km · Saku 20 km · Annaka 24 km · Tōmi 24 km · Tomioka 26 km · Ueda 32 km · Nakanojō 32 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 Karuizawa (36.35°, 138.6333°, elevation 952 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. 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).