Arai weather in May

In May, Arai sees average daytime highs of 23°C and overnight lows near 15°C, with 170 mm of rain across 11.3 wet days and about 13.8 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 22°C in the first days to 25°C by the end. The sky is clear or mostly clear about 27% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of May to 14 h 06 min by month's end. Set against the rest of the year, May is Arai's 10th-clearest and 7th-windiest month. For the whole year in context, see Arai's year-round climate.

Daytime high
23°
5th warmest
Overnight low
15°
7th coldest
Rainfall
170 mm
11.3 wet days
Daylight
13 h 48 min
4:52 AM – 6:40 PM
Cloud cover
66%
10th clearest
Wind
13 km/h
7th windiest
Solar energy
5.4 kWh/m²
Travel score
6.5
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 22°C in the first days to 25°C by the end.

A typical May day in Arai reaches about 23°C in the afternoon and slips back to 15°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 27°C. Set against its neighbours, May runs about 4°C warmer than April and about 3°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12213
22213
32214
42214
52214
62214
72214
82214
92314
102315
112315
122315
132315
142315
152315
162315
172316
182416
192416
202416
212416
222416
232416
242416
252417
262417
272417
282517
292517
302517
312517

How May really feels in Arai

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.

Arai weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan10° / 655.89.92.6
Feb11° / 816.810.73.0
Mar14° / 13510.511.74.3
Apr19° / 11°15110.412.86.0
May23° / 15°17011.313.86.5
Jun26° / 20°24215.614.35.4
Jul30° / 24°25015.814.14.2
Aug31° / 25°14415.313.33.8
Sep28° / 22°23614.612.25.2
Oct23° / 16°21111.811.16.6
Nov18° / 10°1138.910.25.9
Dec12° / 676.39.73.9

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 11% of May, with mostly cloudy or overcast conditions the remaining 62%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34357
44258
54159
64060
74060
83961
93862
103862
113763
123763
133862
143862
153862
163862
173862
183862
193862
203763
213763
223763
233763
243664
253763
263763
273664
283664
293565
303466
313367

Chance of precipitation in May

Any precipitation

Arai gets around 170 mm of rain over 11.3 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 36% and peaks near 38% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
234
334
435
535
635
736
836
937
1037
1137
1238
1338
1437
1537
1637
1737
1836
1936
2036
2136
2235
2335
2435
2535
2635
2735
2835
2936
3036
3137

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 44% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
16823810
26624910
36525910
463261010
561271020
659281120
757291220
856301220
954311320
1052321330
1151331330
1250341330
1348351330
1446371430
1545381430
1643391440
1742401540
1840411540
1939411640
2037411750
2136421850
2234421950
2333422050
2431422160
2530422260
2628412460
2727412560
2825402770
2924392971
3022383181
3121373391

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612calm
2712calm
2812calm
2912calm
3012calm
3112calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 24 min at the start of May to 14 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over May. Sunrise moves from 5:06 AM to 4:43 AM, and sunset from 6:28 PM to 6:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:066:28
213.45:056:29
313.45:046:30
413.55:036:31
513.55:016:31
613.55:006:32
713.65:006:33
813.64:596:34
913.64:586:35
1013.64:576:35
1113.74:566:36
1213.74:556:37
1313.74:546:38
1413.84:536:39
1513.84:526:39
1613.84:526:40
1713.84:516:41
1813.94:506:42
1913.94:506:43
2013.94:496:43
2113.94:486:44
2214.04:486:45
2314.04:476:46
2414.04:466:46
2514.04:466:47
2614.04:456:48
2714.14:456:48
2814.14:446:49
2914.14:446:50
3014.14:446:50
3114.14:436:51

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.4 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.62 kWh/m² to a high of 5.4 kWh/m² in May across the year — May's 5.4 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.3Bright
125.3Bright
135.4Bright
145.4Bright
155.4Bright
165.4Bright
175.4Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.4Bright
315.4Bright
Planning a trip in May

Hazard calendar for Arai

In seasonPeak

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

Arai 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 May a good time to visit Arai?

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

6.5
Sightseeing
2nd-best month of the year
5.2
Beach & pool
5th-best month of the year

May is a reasonable time to visit Arai for sightseeing.

What to pack for Arai in May

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

In May, Arai sees daytime highs around 23°C and nights near 15°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Arai in May

The nearest coast averages about 19°C in May — 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 February near 16°C.

It's comfortable for a long swim from May 25 to Nov 28 — about 6.2 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb16Cool
Mar16Cool
Apr17Cool
May19Cool
Jun22Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov21Refreshing
Dec19Cool

UV index in Arai in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May 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 Arai peaks around July 15 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 highModerateJul 15UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5Moderate
Apr7High
May9Very high
Jun10Very high
Jul10Very high
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Arai 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 Arai is worst in April — around 25 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (July, 15 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1325 µg/m³Jul 2415 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb19Moderate
Mar25Moderate
Apr25Moderate
May24Moderate
Jun20Moderate
Jul15Moderate
Aug15Moderate
Sep16Moderate
Oct18Moderate
Nov18Moderate
Dec16Moderate
Location & terrain

Where is Arai?

Arai sits at 34.7°N, 137.6°E, 2 m above sea level, in Japan. The nearest listed city is Kosai, 4.0 km away.

Topography around Arai

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

Within 3 km, the terrain around Arai has only modest variations in elevation — a maximum elevation change of 83 m around an average of 7 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 450 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,300 m.

The land around Arai is covered by water (60%) within 3 km, water (54%) and trees (21%) within 16 km, and water (44%) and trees (42%) within 80 km.

3 km
83 m
16 km
450 m
80 km
2,300 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Kosai 4.0 km · Hamamatsu 15 km · Toyohashi 19 km · Toyokawa 21 km · Kozakai-chō 23 km · Hamakita 24 km · Shinshiro 25 km · Iwata 26 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 Arai (34.6833°, 137.5667°, elevation 2 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).