Itoigawa weather in August

In August, Itoigawa sees average daytime highs of 27°C and overnight lows near 23°C, with 197 mm of rain across 18.1 wet days and about 13.4 hours of daylight. It is the 1st-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 21% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 54 min at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Itoigawa's 5th-clearest and 12th-windiest month. For the whole year in context, see Itoigawa's year-round climate.

Daytime high
27°
1st warmest
Overnight low
23°
12th coldest
Rainfall
197 mm
18.1 wet days
Daylight
13 h 24 min
5:10 AM – 6:36 PM
Cloud cover
65%
5th clearest
Wind
6 km/h
12th windiest
Solar energy
5.08 kWh/m²
Travel score
5.3
out of 10

Itoigawa is city in Niigata prefecture, Japan.

Density
55/km²
people per km²
Founded
1954

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical August day in Itoigawa reaches about 27°C in the afternoon and slips back to 23°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 29°C. Set against its neighbours, August runs about 2°C warmer than July and about 4°C warmer than September.

15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12723
22723
32723
42723
52724
62724
72724
82724
92724
102723
112723
122723
132723
142723
152723
162723
172723
182723
192723
202723
212723
222623
232623
242623
252623
262622
272622
282622
292622
302622
312622

How August really feels in Itoigawa

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.

Itoigawa weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -0°28826.322.89.70.0
Feb / -1°21921.818.710.60.0
Mar / 20020.512.911.70.4
Apr11° / 14314.82.412.92.6
May17° / 12°13914.20144.9
Jun21° / 17°17314.3014.55.5
Jul25° / 21°25418.8014.35.3
Aug27° / 23°19718.1013.45.3
Sep23° / 19°23518.2012.35.3
Oct18° / 14°21617.30114.7
Nov12° / 21319.12.4102.5
Dec / 27424.315.19.50.4

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% 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 61%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24159
34159
44159
54159
64060
74159
84159
94060
104060
113961
123961
133961
143862
153961
163862
173862
183862
193862
203961
213862
223862
233862
243862
253763
263763
273664
283664
293664
303565
313565

Chance of precipitation in August

Any precipitation

Itoigawa gets around 197 mm of rain over 18.1 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 59% and peaks near 65% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
155
255
356
456
556
656
756
856
956
1057
1157
1257
1357
1458
1558
1658
1758
1859
1959
2059
2160
2260
2361
2461
2562
2662
2763
2864
2964
3064
3165

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 93% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10233632
20231652
30230662
40229672
50228682
60227683
70227683
80226693
90226693
100226693
110326683
120326683
131326673
141327663
151427653
161428643
171529623
181531603
191632583
201633573
211735543
222736523
232838503
242839483
252940463
2621042443
2721143423
2821144403
2921245382
3031346372
3131446352

Wind in August

Winds average 6 km/h in August, the calmest month.

Across August, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 54 min at the start of August to 12 h 54 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 5:23 AM, and sunset from 6:52 PM to 6:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.94:576:52
213.94:586:51
313.94:596:50
413.85:006:49
513.85:006:48
613.85:016:47
713.75:026:46
813.75:036:45
913.75:046:44
1013.65:056:43
1113.65:066:42
1213.65:066:41
1313.55:076:39
1413.55:086:38
1513.55:096:37
1613.45:106:36
1713.45:116:34
1813.45:116:33
1913.35:126:32
2013.35:136:30
2113.25:146:29
2213.25:156:28
2313.25:166:26
2413.15:176:25
2513.15:176:23
2613.15:186:22
2713.05:196:21
2813.05:206:19
2912.95:216:18
3012.95:226:16
3112.95:236:15

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.08 kWh/m².

For context, solar energy here swings from a low near 1.88 kWh/m² to a high of 5.67 kWh/m² in May across the year — August's 5.08 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.3Bright
95.3Bright
105.3Bright
115.2Bright
125.2Bright
135.2Bright
145.1Bright
155.1Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
204.9Bright
214.9Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.7Bright
274.7Bright
284.6Bright
294.6Bright
304.5Bright
314.5Bright
Planning a trip in August

Hazard calendar for Itoigawa

In seasonPeak

In August, Itoigawa sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Itoigawa sits in the Pacific typhoon belt; the season peaks July–October.

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

Is August a good time to visit Itoigawa?

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

5.3
Sightseeing
2nd-best month of the year
5.3
Beach & pool
1st-best month of the year

August is a reasonable time to visit Itoigawa for sightseeing.

What to pack for Itoigawa in August

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

In August, Itoigawa sees daytime highs around 27°C and nights near 23°C. Pack rain gear. Worth having: light clothes and sun protection. About 18 days see rain.

rain gearlight clothessun protection

Sea temperature near Itoigawa 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 offshore is warmest in August at about 27°C and coldest in March near 10°C.

It's comfortable for a long swim from Jun 20 to Nov 1 — about 4.4 months when the water holds above 20°C.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb11Bracing
Mar10Bracing
Apr11Bracing
May15Bracing
Jun20Cool
Jul23Refreshing
Aug27Warm
Sep25Warm
Oct22Refreshing
Nov19Cool
Dec15Cool

UV index in Itoigawa 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 Itoigawa peaks around August 12 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 12UV 10Dec 20UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul10Very high
Aug10Very high
Sep9Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Itoigawa 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 Itoigawa 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 1721 µg/m³Dec 1510 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar20Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug13Moderate
Sep12Good
Oct11Good
Nov11Good
Dec10Good
Location & terrain

Where is Itoigawa?

Itoigawa sits at 37.0°N, 137.8°E, 15 m above sea level, in Japan. The nearest listed city is Nyūzen, 33 km away.

Topography around Itoigawa

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

Within 3 km, the terrain around Itoigawa has significant variations in elevation — a maximum elevation change of 312 m around an average of 44 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,586 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,069 m.

The land around Itoigawa is covered by trees (35%), water (30%) and artificial surfaces (24%) within 3 km, trees (50%) and water (45%) within 16 km, and trees (49%) and water (40%) within 80 km.

3 km
312 m
16 km
1,586 m
80 km
3,069 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Nyūzen 33 km · Arai 34 km · Myoko 36 km · Jōetsu 37 km · Kurobe-shi 38 km · Uozu 48 km · Iiyama 50 km · Nagano 52 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 Itoigawa (37.0333°, 137.85°, elevation 15 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).