Karuizawa weather in July

In July, Karuizawa sees average daytime highs of 25°C and overnight lows near 19°C, with 282 mm of rain across 24 wet days and about 14.2 hours of daylight. It is the 2nd-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 24°C in the first days to 26°C by the end. The sky is clear or mostly clear about 10% of the time in July, and the air most often feels muggy.

Daylight stretches from about 14 h 30 min at the start of July to 13 h 54 min by month's end. Set against the rest of the year, July is Karuizawa's 11th-clearest and 12th-windiest month. For the whole year in context, see Karuizawa's year-round climate.

Daytime high
25°
2nd warmest
Overnight low
19°
11th coldest
Rainfall
282 mm
24 wet days
Daylight
14 h 18 min
4:44 AM – 6:59 PM
Cloud cover
78%
11th clearest
Wind
4 km/h
12th windiest
Solar energy
4.73 kWh/m²
Travel score
4.5
out of 10

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 24°C in the first days to 26°C by the end.

A typical July day in Karuizawa reaches about 25°C in the afternoon and slips back to 19°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 30°C. Set against its neighbours, July runs about 4°C warmer than June and about 1°C cooler than August.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12317
22417
32417
42418
52418
62418
72418
82418
92518
102518
112518
122518
132518
142519
152519
162519
172519
182619
192619
202619
212619
222619
232619
242619
252619
262619
272620
282620
292720
302720
312720

How July really feels in Karuizawa

Once humidity and wind are folded in, July 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

July 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 July compares with the rest of the year at a glance. July is the 2nd-warmest and 1st-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 July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in July.

Beyond those clear spells, partly cloudy skies cover about 12% of July, with mostly cloudy or overcast conditions the remaining 77%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11585
21783
31783
41783
51882
61981
71981
81981
92080
102080
112080
122080
132179
142179
152179
162179
172278
182377
192377
202377
212377
222476
232575
242674
252674
262872
272872
282971
293070
303169
313268

Chance of precipitation in July

Any precipitation

Karuizawa gets around 282 mm of rain over 24 wet days in July, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 77% and peaks near 80% on the wettest days.

0%20%40%60%80%151015202531
Rain chance (%)
180
280
380
480
580
680
780
880
980
1080
1180
1280
1379
1479
1578
1677
1777
1876
1976
2076
2175
2275
2375
2475
2574
2674
2774
2875
2975
3075
3175

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the muggy band about 46% of days. Sticky, muggy-or-worse air turns up on roughly 48% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
162451190
252252210
342152230
431953250
531852270
621753280
711653300
811552320
911450341
1011450351
1101349371
1201348381
1301246401
1401145421
1501144441
1601042462
170941482
180939502
190838522
200836542
210734572
220733582
230631603
240630613
250528643
260526663
270525664
280423694
290422704
300421705
310320725

Wind in July

Winds average 4 km/h in July, the calmest month.

Across July, daily wind ranges from about 4 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in July

DaylightNight

Daylight runs from about 14 h 30 min at the start of July to 13 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 36 minutes over July. Sunrise moves from 4:35 AM to 4:55 AM, and sunset from 7:02 PM to 6:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.54:357:02
214.44:367:02
314.44:367:02
414.44:377:02
514.44:377:02
614.44:387:02
714.44:387:02
814.44:397:01
914.44:397:01
1014.44:407:01
1114.34:407:01
1214.34:417:00
1314.34:427:00
1414.34:427:00
1514.34:436:59
1614.34:446:59
1714.24:446:58
1814.24:456:58
1914.24:466:57
2014.24:466:57
2114.14:476:56
2214.14:486:55
2314.14:486:55
2414.14:496:54
2514.14:506:53
2614.04:516:53
2714.04:516:52
2814.04:526:51
2914.04:536:50
3013.94:546:49
3113.94:556:49

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 4.73 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 — July's 4.73 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.6Bright
114.6Bright
124.6Bright
134.6Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.8Bright
194.8Bright
204.8Bright
214.9Bright
224.9Bright
234.9Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.1Bright
295.1Bright
305.1Bright
315.1Bright
Planning a trip in July

Hazard calendar for Karuizawa

In seasonPeak

In July, 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 July a good time to visit Karuizawa?

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

4.5
Sightseeing
4th-best month of the year
4.1
Beach & pool
2nd-best month of the year

July is a reasonable time to visit Karuizawa for sightseeing.

What to pack for Karuizawa in July

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

In July, Karuizawa sees daytime highs around 25°C and nights near 19°C. Pack rain gear. Worth having: light clothes and sun protection. About 24 days see rain.

rain gearlight clothessun protection

UV index in Karuizawa in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks around 10 (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 July

GoodModeratePoorUnhealthyVery unhealthy

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