Shiroishi weather in August

In August, Shiroishi sees average daytime highs of 27°C and overnight lows near 20°C, with 160 mm of rain across 15.8 wet days and about 13.5 hours of daylight. It is the 1st-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 26°C by the end. The sky is clear or mostly clear about 16% of the time in August, and the air most often feels muggy.

Daylight stretches from about 14 hours at the start of August to 12 h 54 min by month's end. Set against the rest of the year, August is Shiroishi's 9th-clearest and 11th-windiest month. For the whole year in context, see Shiroishi's year-round climate.

Daytime high
27°
1st warmest
Overnight low
20°
12th coldest
Rainfall
160 mm
15.8 wet days
Daylight
13 h 30 min
4:57 AM – 6:26 PM
Cloud cover
72%
9th clearest
Wind
5 km/h
11th windiest
Solar energy
4.27 kWh/m²
Travel score
5.5
out of 10

Shiroishi is city in Miyagi Prefecture, Japan.

Density
116/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

Highs ease over the month, from about 28°C in the first days to 26°C by the end.

A typical August day in Shiroishi reaches about 27°C in the afternoon and slips back to 20°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 32°C. Set against its neighbours, August runs about 1°C warmer than July and about 4°C warmer than September.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12821
22821
32821
42821
52821
62821
72821
82821
92821
102821
112821
122821
132721
142721
152721
162721
172720
182720
192720
202720
212720
222720
232720
242720
252620
262620
272620
282619
292619
302619
312619

How August really feels in Shiroishi

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.

Shiroishi weather by month

How August compares with the rest of the year at a glance. August is the 1st-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°7814.5159.70.0
Feb / -4°5811.911.710.50.0
Mar / -1°9213.48.211.71.0
Apr14° / 9512.51.8133.8
May19° / 10°9812.40145.7
Jun22° / 15°12613.6014.65.8
Jul26° / 19°18818.2014.45.2
Aug27° / 20°16015.8013.55.5
Sep23° / 16°15314012.35.8
Oct18° / 10°13511.50115.4
Nov12° / 7111.629.92.9
Dec / -1°6914.510.19.40.3

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 14% of August, with mostly cloudy or overcast conditions the remaining 70%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13070
23070
33070
43070
53070
63070
73070
83070
93070
103070
112971
123070
133070
142971
152872
162872
172971
182971
192971
203070
213070
223070
233070
243070
253070
263070
272971
283070
293070
303169
313169

Chance of precipitation in August

Any precipitation

Shiroishi gets around 160 mm of rain over 15.8 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 51% and peaks near 52% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
150
250
350
450
549
649
750
850
950
1050
1151
1251
1351
1451
1551
1651
1751
1851
1951
2051
2151
2252
2352
2452
2552
2652
2752
2851
2951
3051
3151

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 39% of days. Sticky, muggy-or-worse air turns up on roughly 77% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1041242411
2041241431
3041240431
4041240441
5031239441
6031339451
7041338451
8041338451
9041338441
10041438441
11041438441
12041438431
13041439421
14041439420
15041539410
16051539400
17051539400
18061639390
19161639380
20161739370
21171739360
22171839350
23172039340
24172139320
25172239310
26182339290
27182539280
28182639260
29182739250
30192938230
31193038220

Wind in August

Winds average 5 km/h in August.

Across August, daily wind ranges from about 5 km/h on the calmest days to 6 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
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 hours 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 66 minutes over August. Sunrise moves from 4:44 AM to 5:11 AM, and sunset from 6:43 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.04:446:43
214.04:456:42
313.94:466:41
413.94:476:40
513.94:476:39
613.84:486:38
713.84:496:37
813.84:506:36
913.74:516:35
1013.74:526:34
1113.74:536:32
1213.64:546:31
1313.64:546:30
1413.64:556:29
1513.54:566:27
1613.54:576:26
1713.44:586:25
1813.44:596:23
1913.45:006:22
2013.35:016:21
2113.35:026:19
2213.35:036:18
2313.25:036:16
2413.25:046:15
2513.15:056:14
2613.15:066:12
2713.15:076:11
2813.05:086:09
2913.05:096:08
3012.95:106:06
3112.95:116:05

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.27 kWh/m².

For context, solar energy here swings from a low near 2.03 kWh/m² to a high of 5.33 kWh/m² in May across the year — August's 4.27 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.4Bright
124.4Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.2Bright
194.2Bright
204.1Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Bright
264.0Moderate
274.0Moderate
283.9Moderate
293.9Moderate
303.9Moderate
313.8Moderate
Planning a trip in August

Hazard calendar for Shiroishi

In seasonPeak

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

Shiroishi 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 Shiroishi?

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

5.5
Sightseeing
4th-best month of the year
5.6
Beach & pool
1st-best month of the year

August is a reasonable time to visit Shiroishi for sightseeing.

What to pack for Shiroishi in August

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

In August, Shiroishi sees daytime highs around 27°C and nights near 20°C. Pack light clothes and rain gear. About 16 days see rain.

light clothesrain gear

Sea temperature near Shiroishi in August

The nearest coast averages about 24°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 46 km away) is warmest in August at about 24°C and coldest in March near 9°C.

It's comfortable for a long swim from Jul 7 to Oct 10 — about 3.2 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan11Bracing
Feb9Bracing
Mar9Bracing
Apr10Bracing
May14Bracing
Jun18Cool
Jul21Refreshing
Aug24Refreshing
Sep23Refreshing
Oct19Cool
Nov17Cool
Dec14Bracing

UV index in Shiroishi 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 Shiroishi peaks around August 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 13UV 9Jan 10UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul9Very high
Aug9Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low

Air quality in Shiroishi 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 Shiroishi is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1622 µg/m³Dec 1710 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar21Moderate
Apr22Moderate
May21Moderate
Jun16Moderate
Jul14Moderate
Aug12Moderate
Sep12Good
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Shiroishi?

Shiroishi sits at 38.0°N, 140.6°E, 57 m above sea level, in Japan. The nearest listed city is Ōkawara, 11 km away.

Topography around Shiroishi

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

Within 3 km, the terrain around Shiroishi has significant variations in elevation — a maximum elevation change of 493 m around an average of 100 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,805 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,031 m.

The land around Shiroishi is covered by trees (50%), cropland (23%) and artificial surfaces (23%) within 3 km, trees (80%) within 16 km, and trees (63%) and water (20%) within 80 km.

3 km
493 m
16 km
1,805 m
80 km
2,031 m
treesgrasslandcroplandartificial surfacesbare terrainwater
August weather nearby: Ōkawara 11 km · Kakuda 14 km · Murata 16 km · Yanagawamachi-saiwaichō 17 km · Watari 21 km · Hobaramachi 22 km · Date 23 km · Iwanuma 24 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 Shiroishi (38.0033°, 140.6183°, elevation 57 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).