Yanai weather in August

In August, Yanai sees average daytime highs of 29°C and overnight lows near 25°C, with 143 mm of rain across 11.5 wet days and about 13.3 hours of daylight. It is the 1st-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 35% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 13 h 42 min at the start of August to 12 h 48 min by month's end. Set against the rest of the year, August is Yanai's 7th-clearest and 10th-windiest month. For the whole year in context, see Yanai's year-round climate.

Daytime high
29°
1st warmest
Overnight low
25°
12th coldest
Rainfall
143 mm
11.5 wet days
Daylight
13 h 18 min
5:37 AM – 6:54 PM
Cloud cover
58%
7th clearest
Wind
11 km/h
10th windiest
Solar energy
5.2 kWh/m²
Travel score
5.5
out of 10

Yanai is city in Yamaguchi Prefecture, Japan.

Density
232/km²
people per km²
Founded
2005

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 29°C through the month.

A typical August day in Yanai reaches about 29°C in the afternoon and slips back to 25°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 31°C. Set against its neighbours, August runs about 1°C warmer than July and about 3°C warmer than September.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12925
22926
32926
42926
52926
62926
72926
82926
92926
102926
112926
122926
132926
142926
152926
162926
172925
182925
192925
202925
212925
222925
232925
242825
252825
262825
272825
282825
292825
302824
312824

How August really feels in Yanai

Once humidity and wind are folded in, August averages 24 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
24
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Yanai weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 588.10.8101.9
Feb10° / 748.80.810.72.1
Mar12° / 1229.90.111.73.4
Apr16° / 12°1469.9012.85.2
May20° / 16°16710013.76.3
Jun23° / 20°25313.5014.26.0
Jul27° / 24°23913.80145.6
Aug29° / 25°14311.5013.35.5
Sep26° / 22°16911.2012.26.5
Oct22° / 17°1207.7011.17.1
Nov17° / 12°767.8010.25.7
Dec12° / 6890.29.83.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 15% of August, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15149
25149
35149
45149
55248
65248
75149
85050
95050
105050
115050
125050
134951
144951
154951
164852
174852
184951
194951
204951
214951
224951
234951
244852
254852
264852
274852
284852
294852
304852
314852

Chance of precipitation in August

Any precipitation

Yanai gets around 143 mm of rain over 11.5 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 38% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
336
435
535
635
736
836
936
1036
1137
1237
1338
1438
1539
1639
1739
1839
1939
2039
2139
2239
2339
2439
2539
2640
2740
2840
2940
3040
3140

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 46% of days. Sticky, muggy-or-worse air turns up on roughly 98% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1034651
2024553
3024553
4024454
5024355
6034354
7034354
8034255
9034255
10034255
11034354
12044353
13044353
14144352
15144451
16154450
17154549
18164548
19164646
20274645
21284743
22294841
232104839
243114937
253125035
263135133
274155031
284165129
294185127
305195125
315215123

Wind in August

Winds average 11 km/h in August.

Across August, daily wind ranges from about 11 km/h on the calmest days to 12 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
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3112calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 13 h 42 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 54 minutes over August. Sunrise moves from 5:26 AM to 5:48 AM, and sunset from 7:09 PM to 6:35 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:267:09
213.75:277:08
313.75:287:07
413.65:297:06
513.65:297:05
613.65:307:04
713.55:317:03
813.55:317:02
913.55:327:01
1013.55:337:00
1113.45:346:59
1213.45:346:58
1313.45:356:57
1413.35:366:56
1513.35:376:55
1613.35:376:54
1713.25:386:53
1813.25:396:52
1913.25:406:50
2013.15:406:49
2113.15:416:48
2213.15:426:47
2313.05:426:45
2413.05:436:44
2513.05:446:43
2612.95:456:42
2712.95:456:40
2812.95:466:39
2912.85:476:38
3012.85:486:36
3112.85:486:35

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.2 kWh/m².

For context, solar energy here swings from a low near 2.33 kWh/m² to a high of 5.51 kWh/m² in May across the year — August's 5.2 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.4Bright
75.4Bright
85.4Bright
95.4Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.2Bright
165.2Bright
175.2Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
264.9Bright
274.9Bright
284.8Bright
294.8Bright
304.8Bright
314.8Bright
Planning a trip in August

Hazard calendar for Yanai

In seasonPeak

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

Yanai 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 Yanai?

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

5.5
Sightseeing
7th-best month of the year
6.7
Beach & pool
1st-best month of the year

August is a reasonable time to visit Yanai for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Yanai in August

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

In August, Yanai sees daytime highs around 29°C and nights near 25°C. Pack light clothes. Worth having: rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

Sea temperature near Yanai 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 25 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 9 to Nov 16 — about 5.3 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep25Warm
Oct23Refreshing
Nov20Refreshing
Dec17Cool

UV index in Yanai in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 Yanai peaks around June 23 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJun 23UV 10Dec 21UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May8Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Yanai 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 Yanai is worst in April — around 23 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateModerateApr 1323 µg/m³Oct 1612 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar23Moderate
Apr23Moderate
May22Moderate
Jun19Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct11Good
Nov13Moderate
Dec13Moderate
Location & terrain

Where is Yanai?

Yanai sits at 34.0°N, 132.1°E, 0 m above sea level, in Japan. The nearest listed city is Hikari, 15 km away.

Topography around Yanai

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

Within 3 km, the terrain around Yanai has significant variations in elevation — a maximum elevation change of 525 m around an average of 91 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 682 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,334 m.

The land around Yanai is covered by trees (59%) and artificial surfaces (23%) within 3 km, trees (56%) and water (32%) within 16 km, and trees (49%) and water (45%) within 80 km.

3 km
525 m
16 km
682 m
80 km
1,334 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Hikari 15 km · Kudamatsu 24 km · Iwakuni 24 km · Ōtake 28 km · Tokuyama 29 km · Shūnan 30 km · Ōno-hara 38 km · Miyajima 42 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 Yanai (33.9667°, 132.1167°, elevation 0 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).