Hachimantai weather in August

In August, Hachimantai sees average daytime highs of 25°C and overnight lows near 18°C, with 141 mm of rain across 14.9 wet days and about 13.6 hours of daylight. It is the 1st-warmest and 2nd-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 14 h 06 min at the start of August to 13 hours by month's end. Set against the rest of the year, August is Hachimantai's 10th-clearest and 11th-windiest month. For the whole year in context, see Hachimantai's year-round climate.

Daytime high
25°
1st warmest
Overnight low
18°
12th coldest
Rainfall
141 mm
14.9 wet days
Daylight
13 h 36 min
4:52 AM – 6:27 PM
Cloud cover
72%
10th clearest
Wind
7 km/h
11th windiest
Solar energy
4.24 kWh/m²
Travel score
5.9
out of 10

Hachimantai is city in Iwate Prefecture, Japan.

Density
29/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

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

A typical August day in Hachimantai reaches about 25°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 21°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°35°151015202531
Avg high (°C)Avg low (°C)
12619
22619
32619
42619
52619
62619
72619
82619
92619
102619
112619
122619
132619
142619
152519
162519
172518
182518
192518
202518
212518
222518
232518
242518
252518
262518
272417
282417
292417
302417
312417

How August really feels in Hachimantai

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.

Hachimantai 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-1° / -9°6010.513.29.50.0
Feb / -8°5910.412.110.40.0
Mar / -4°9014.212.111.70.2
Apr11° / 9014.14132.6
May17° / 9312.70.314.25.1
Jun21° / 13°10512.8014.85.7
Jul24° / 17°14416.4014.55.6
Aug25° / 18°14114.9013.65.9
Sep21° / 14°13812.9012.35.8
Oct15° / 11111.20.110.94.5
Nov / 7612.849.81.4
Dec / -5°7412129.20.0

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 13% of August, with mostly cloudy or overcast conditions the remaining 72%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13070
23169
33070
43070
53070
63070
72971
82971
92971
103070
112971
122872
132872
142872
152872
162872
172872
182872
192971
202971
212971
222872
232773
242773
252773
262773
272674
282674
292674
302773
312773

Chance of precipitation in August

Any precipitation

Hachimantai gets around 141 mm of rain over 14.9 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 48% and peaks near 50% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
145
245
345
445
545
645
745
845
946
1046
1146
1246
1347
1447
1548
1648
1748
1848
1949
2049
2149
2249
2349
2449
2550
2650
2750
2850
2950
3050
3150

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 57% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
121021589
221021589
321021589
421021589
521021589
6210215710
7210215710
8210215710
9210225610
10210235510
11211235410
12211245310
13211255210
14211265011
15211274911
16311274811
17312284611
18412294511
19412294410
20513294310
21513304210
2261430419
2361530409
2471531398
2571631398
2671631387
2781732376
2881832366
2981932356
3082032345
3192133335

Wind in August

Winds average 7 km/h in August.

Across August, daily wind ranges from about 7 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
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 06 min at the start of August to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over August. Sunrise moves from 4:38 AM to 5:07 AM, and sunset from 6:45 PM to 6:04 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.14:386:45
214.14:396:44
314.14:396:43
414.04:406:42
514.04:416:41
614.04:426:40
713.94:436:39
813.94:446:38
913.94:456:36
1013.84:466:35
1113.84:476:34
1213.74:486:33
1313.74:496:31
1413.74:506:30
1513.64:516:29
1613.64:526:27
1713.54:536:26
1813.54:546:24
1913.54:556:23
2013.44:566:21
2113.44:576:20
2213.34:586:19
2313.34:596:17
2413.35:006:16
2513.25:016:14
2613.25:026:12
2713.15:036:11
2813.15:046:09
2913.15:056:08
3013.05:066:06
3113.05:076:04

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.24 kWh/m².

For context, solar energy here swings from a low near 1.87 kWh/m² to a high of 5.27 kWh/m² in May across the year — August's 4.24 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.2Bright
194.1Bright
204.1Bright
214.1Bright
224.1Bright
234.0Bright
244.0Bright
254.0Moderate
264.0Moderate
273.9Moderate
283.9Moderate
293.9Moderate
303.9Moderate
313.9Moderate
Planning a trip in August

Is August a good time to visit Hachimantai?

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

5.9
Sightseeing
1st-best month of the year
5.4
Beach & pool
1st-best month of the year

August is a reasonable time to visit Hachimantai for sightseeing.

What to pack for Hachimantai in August

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

In August, Hachimantai sees daytime highs around 25°C and nights near 18°C. Pack rain gear. Worth having: light clothes. About 15 days see rain.

rain gearlight clothes

Sea temperature near Hachimantai in August

The nearest coast averages about 21°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 68 km away) is warmest in August at about 21°C and coldest in March near 6°C.

It's comfortable for a long swim from Aug 8 to Sep 25 — about 1.6 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan10Bracing
Feb8Bracing
Mar6Bracing
Apr7Bracing
May10Bracing
Jun14Bracing
Jul18Cool
Aug21Refreshing
Sep21Refreshing
Oct18Cool
Nov15Cool
Dec12Bracing

UV index in Hachimantai 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 Hachimantai peaks around August 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighVery highHighModerateLowAug 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul6High
Aug9Very high
Sep7High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Hachimantai 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 Hachimantai is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1420 µg/m³Dec 1610 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May19Moderate
Jun14Moderate
Jul12Moderate
Aug11Good
Sep11Good
Oct12Good
Nov11Good
Dec9Good
Location & terrain

Where is Hachimantai?

Hachimantai sits at 39.9°N, 141.1°E, 228 m above sea level, in Japan. The nearest listed city is Takizawa, 11 km away.

Topography around Hachimantai

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

Within 3 km, the terrain around Hachimantai has only modest variations in elevation — a maximum elevation change of 149 m around an average of 245 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,870 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,117 m.

The land around Hachimantai is covered by cropland (46%) and trees (38%) within 3 km, trees (75%) within 16 km, and trees (84%) within 80 km.

3 km
149 m
16 km
1,870 m
80 km
2,117 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Takizawa 11 km · Morioka 22 km · Shizukuishi 26 km · Yahaba 32 km · Semboku 39 km · Hizume 39 km · Hanawa 43 km · Ninohe 46 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 Hachimantai (39.8998°, 141.1299°, elevation 228 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).