Isawa weather in August

In August, Isawa sees average daytime highs of 26°C and overnight lows near 18°C, with 189 mm of rain across 21.7 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 24°C by the end. The sky is clear or mostly clear about 15% of the time in August, and the air most often feels muggy.

Daylight stretches from about 13 h 48 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Isawa's 9th-clearest and 12th-windiest month. For the whole year in context, see Isawa's year-round climate.

Daytime high
26°
1st warmest
Overnight low
18°
12th coldest
Rainfall
189 mm
21.7 wet days
Daylight
13 h 24 min
5:09 AM – 6:30 PM
Cloud cover
71%
9th clearest
Wind
4 km/h
12th windiest
Solar energy
4.72 kWh/m²
Travel score
4.9
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

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

A typical August day in Isawa reaches about 26°C in the afternoon and slips back to 18°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 29°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12619
22619
32619
42619
52619
62619
72619
82619
92619
102619
112619
122619
132619
142619
152619
162619
172619
182618
192518
202518
212518
222518
232518
242518
252518
262518
272518
282518
292518
302418
312417

How August really feels in Isawa

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.

Isawa weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -6°6676.59.90.0
Feb / -6°718.46.610.70.0
Mar / -2°12913.57.911.71.0
Apr13° / 13113.92.212.93.5
May18° / 14715.10.213.95.1
Jun21° / 14°20519.8014.44.6
Jul25° / 18°23421.9014.24.8
Aug26° / 18°18921.7013.34.9
Sep22° / 15°22018.6012.25.1
Oct16° / 21215.5011.14.5
Nov11° / 8810.10.510.12.8
Dec / -3°607.64.19.60.4

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 17% of August, with mostly cloudy or overcast conditions the remaining 68%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13268
23268
33268
43268
53268
63367
73367
83367
93268
103169
113169
123169
133268
143169
153169
163169
173268
183268
193268
203268
213268
223268
233268
243268
253268
263268
273268
283268
293268
303169
313268

Chance of precipitation in August

Any precipitation

Isawa gets around 189 mm of rain over 21.7 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 69% and peaks near 72% on the wettest days.

0%20%40%60%80%151015202531
Rain chance (%)
171
271
371
472
572
672
772
872
972
1071
1171
1271
1370
1470
1570
1670
1770
1869
1969
2069
2168
2268
2368
2467
2567
2667
2767
2867
2966
3066
3166

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

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

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1054154
2054154
3044056
4043957
5043957
6043858
7043858
8043759
9043759
10053758
11053758
12153757
13163756
14163756
15163855
16173854
17183952
18184051
19194149
201104247
211104345
221114443
232124641
242124739
252134837
262144935
272155033
282155231
292165329
303175327
313185326

Wind in August

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

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

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 48 min at the start of August to 12 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over August. Sunrise moves from 4:57 AM to 5:21 AM, and sunset from 6:46 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.84:576:46
213.84:586:45
313.84:586:44
413.74:596:43
513.75:006:42
613.75:016:41
713.65:026:40
813.65:026:39
913.65:036:38
1013.65:046:37
1113.55:056:36
1213.55:066:35
1313.55:066:34
1413.45:076:33
1513.45:086:32
1613.45:096:30
1713.35:106:29
1813.35:106:28
1913.35:116:27
2013.25:126:25
2113.25:136:24
2213.25:146:23
2313.15:146:21
2413.15:156:20
2513.05:166:19
2613.05:176:17
2713.05:186:16
2812.95:186:15
2912.95:196:13
3012.95:206:12
3112.85:216:10

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.72 kWh/m².

For context, solar energy here swings from a low near 2.57 kWh/m² to a high of 5.33 kWh/m² in May across the year — August's 4.72 kWh/m² sits near the top of that range.

024151015202531
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
74.9Bright
84.9Bright
94.9Bright
104.9Bright
114.8Bright
124.8Bright
134.8Bright
144.8Bright
154.7Bright
164.7Bright
174.7Bright
184.7Bright
194.6Bright
204.6Bright
214.6Bright
224.5Bright
234.5Bright
244.5Bright
254.4Bright
264.4Bright
274.4Bright
284.3Bright
294.3Bright
304.3Bright
314.3Bright
Planning a trip in August

Is August a good time to visit Isawa?

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

4.9
Sightseeing
3rd-best month of the year
4.6
Beach & pool
1st-best month of the year

August is a reasonable time to visit Isawa for sightseeing.

What to pack for Isawa in August

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

In August, Isawa sees daytime highs around 26°C and nights near 18°C. Pack rain gear. Worth having: light clothes and sun protection. About 22 days see rain.

rain gearlight clothessun protection

Sea temperature near Isawa in August

The nearest coast averages about 27°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 58 km away) is warmest in August at about 27°C and coldest in February near 15°C.

It's comfortable for a long swim from May 30 to Nov 23 — about 5.9 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Cool
Mar15Cool
Apr17Cool
May19Cool
Jun22Refreshing
Jul24Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Isawa in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 Isawa peaks around July 16 at about 10 (extreme) — 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 highExtremeVery highModerateJul 16UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Very high
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Isawa 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 Isawa 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 Isawa?

Isawa sits at 35.6°N, 138.6°E, 269 m above sea level, in Japan. The nearest listed city is Fuefuki, 2.0 km away.

Topography around Isawa

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

Within 3 km, the terrain around Isawa has significant variations in elevation — a maximum elevation change of 519 m around an average of 308 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,549 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,735 m.

The land around Isawa is covered by artificial surfaces (46%), cropland (28%) and trees (22%) within 3 km, trees (63%) and artificial surfaces (20%) within 16 km, and trees (77%) within 80 km.

3 km
519 m
16 km
1,549 m
80 km
3,735 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Fuefuki 2.0 km · Kofu 6.0 km · Yamanashi 6.0 km · Shōwa 9.0 km · Enzan 11 km · Kai 12 km · Ryūō 12 km · Chūō 13 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 Isawa (35.65°, 138.6333°, elevation 269 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. 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).