Hachimantai weather in May

In May, Hachimantai sees average daytime highs of 17°C and overnight lows near 8°C, with 93 mm of precipitation across 12.7 wet days and about 14.2 hours of daylight. It is the 5th-warmest and 6th-wettest month of the year here.

Highs climb over the month, from about 15°C in the first days to 19°C by the end. The sky is clear or mostly clear about 24% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of May to 14 h 36 min by month's end. Set against the rest of the year, May is Hachimantai's 4th-clearest and 7th-windiest month. For the whole year in context, see Hachimantai's year-round climate.

Daytime high
17°
5th warmest
Overnight low
8th coldest
Precipitation
93 mm
12.7 wet days
Daylight
14 h 12 min
4:26 AM – 6:38 PM
Cloud cover
67%
4th clearest
Wind
10 km/h
7th windiest
Solar energy
5.27 kWh/m²
Travel score
5.1
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 May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 15°C in the first days to 19°C by the end.

A typical May day in Hachimantai reaches about 17°C in the afternoon and slips back to 8°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 22°C. Set against its neighbours, May runs about 6°C warmer than April and about 4°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1156
2156
3156
4166
5166
6167
7167
8167
9167
10167
11168
12178
13178
14178
15178
16178
17178
18179
19189
20189
21189
22189
23189
241810
251810
261910
271910
281910
291910
301910
311911

How May really feels in Hachimantai

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 5th-warmest and 6th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 62%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34456
44258
54159
64060
74060
83961
93862
103862
113862
123664
133664
143664
153763
163763
173664
183664
193664
203763
213763
223763
233763
243862
253961
263961
273961
283961
293862
303862
313862

Chance of precipitation in May

Any precipitationSnow

Hachimantai gets around 93 mm of rain and snow over 12.7 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 41% and peaks near 43% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1435
2435
3434
4424
5423
6423
7423
8422
9422
10421
11421
12421
13421
14420
15420
16420
17410
18410
19410
20410
21410
22410
23400
24400
25400
26400
27390
28390
29390
30390
31390

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
7991
8991
9991
10991
11991
12991
13982
14982
15982
16982
17982
18973
19973
20964
21964
22955
23955
24946
25937
26928
27928
28919
298911
308812
318713

Wind in May

Winds average 10 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 4:43 AM to 4:15 AM, and sunset from 6:23 PM to 6:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.74:436:23
213.74:416:24
313.74:406:25
413.84:396:26
513.84:386:27
613.94:376:28
713.94:356:29
813.94:346:30
914.04:336:31
1014.04:326:32
1114.04:316:33
1214.14:306:34
1314.14:296:35
1414.14:286:36
1514.24:276:37
1614.24:266:38
1714.24:256:39
1814.34:246:39
1914.34:236:40
2014.34:226:41
2114.34:226:42
2214.44:216:43
2314.44:206:44
2414.44:196:45
2514.54:196:46
2614.54:186:47
2714.54:176:47
2814.54:176:48
2914.54:166:49
3014.64:166:50
3114.64:156:51

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.27 kWh/m² — the sunniest month for solar.

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 — May's 5.27 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.2Bright
155.2Bright
165.2Bright
175.2Bright
185.2Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.4Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.5Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in May

Is May a good time to visit Hachimantai?

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

5.1
Sightseeing
5th-best month of the year
1.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Hachimantai for sightseeing.

What to pack for Hachimantai in May

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

In May, Hachimantai sees daytime highs around 17°C and nights near 8°C. Worth packing: rain gear and sun protection. About 13 days see rain.

rain gearsun protection

Sea temperature near Hachimantai in May

The nearest coast averages about 10°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. 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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).