Kai weather in May

In May, Kai sees average daytime highs of 18°C and overnight lows near 9°C, with 130 mm of precipitation across 12.8 wet days and about 13.9 hours of daylight. It is the 5th-warmest and 6th-wettest month of the year here.

Highs climb over the month, from about 17°C in the first days to 20°C by the end. The sky is clear or mostly clear about 22% 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 12 min by month's end. Set against the rest of the year, May is Kai's 9th-clearest and 6th-windiest month. For the whole year in context, see Kai's year-round climate.

Daytime high
18°
5th warmest
Overnight low
8th coldest
Precipitation
130 mm
12.8 wet days
Daylight
13 h 54 min
4:46 AM – 6:39 PM
Cloud cover
68%
9th clearest
Wind
6 km/h
6th windiest
Solar energy
5.51 kWh/m²
Travel score
5.4
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 17°C in the first days to 20°C by the end.

A typical May day in Kai reaches about 18°C in the afternoon and slips back to 9°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 23°C. Set against its neighbours, May runs about 5°C warmer than April and about 3°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1166
2167
3177
4177
5177
6177
7177
8178
9178
10188
11188
12188
13188
14188
15189
16189
17189
18199
19199
20199
211910
221910
231910
241910
251910
261910
271910
282011
292011
302011
312011

How May really feels in Kai

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.

Kai 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 / -7°646.879.90.0
Feb / -6°727.96.510.60.0
Mar / -3°12512.87.611.70.9
Apr13° / 12112.62.112.93.5
May18° / 13012.80.113.95.4
Jun21° / 13°17716.3014.45.2
Jul25° / 17°19917.4014.25.4
Aug26° / 18°13916.8013.35.6
Sep22° / 15°18514.6012.25.7
Oct17° / 18613011.14.9
Nov11° / 859.20.510.12.8
Dec / -3°607.44.29.60.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 63%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34357
44357
54357
64258
74159
84060
94060
104060
113862
123862
133862
143763
153763
163862
173862
183763
193664
203664
213565
223565
233565
243466
253466
263367
273367
283268
293268
303169
312971

Chance of precipitation in May

Any precipitation

Kai gets around 130 mm of rain and snow over 12.8 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 42% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
239
339
439
540
640
740
841
941
1041
1142
1242
1342
1442
1542
1642
1742
1842
1942
2041
2141
2241
2341
2441
2540
2640
2740
2840
2940
3041
3141

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 97% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3982
4982
5982
6982
7982
8982
9982
10973
11973
12973
13973
14973
15973
16973
17973
18973
19973
20973
21964
22964
23964
24964
25964
26964
27964
28955
29955
30946
31946

Wind in May

Winds average 6 km/h in May.

Across May, 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
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 24 min at the start of May to 14 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over May. Sunrise moves from 5:00 AM to 4:37 AM, and sunset from 6:26 PM to 6:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:006:26
213.54:596:27
313.54:586:28
413.54:576:29
513.64:566:29
613.64:556:30
713.64:546:31
813.64:536:32
913.74:526:33
1013.74:516:34
1113.74:506:34
1213.84:496:35
1313.84:486:36
1413.84:476:37
1513.94:476:38
1613.94:466:39
1713.94:456:39
1813.94:446:40
1914.04:446:41
2014.04:436:42
2114.04:426:43
2214.04:426:43
2314.14:416:44
2414.14:406:45
2514.14:406:46
2614.14:396:46
2714.14:396:47
2814.24:386:48
2914.24:386:48
3014.24:376:49
3114.24:376:50

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.51 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.63 kWh/m² to a high of 5.51 kWh/m² in May across the year — May's 5.51 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
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.6Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.4Bright
315.4Bright
Planning a trip in May

Is May a good time to visit Kai?

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

5.4
Sightseeing
3rd-best month of the year
1.9
Beach & pool
5th-best month of the year

May is a reasonable time to visit Kai for sightseeing.

What to pack for Kai in May

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

In May, Kai sees daytime highs around 18°C and nights near 9°C. Worth packing: rain gear and sun protection. About 13 days see rain.

rain gearsun protection

Sea temperature near Kai 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 at the nearest coast (about 63 km away) is warmest in August at about 27°C and coldest in February near 15°C.

It's comfortable for a long swim from May 30 to Nov 23 — about 5.9 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Cool
Mar15Cool
Apr17Cool
May19Cool
Jun22Refreshing
Jul24Warm
Aug27Warm
Sep26Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Kai 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 Kai peaks around July 14 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 2 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJul 14UV 11Dec 21UV 2
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Kai 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 Kai is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1821 µg/m³Dec 1810 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar19Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul15Moderate
Aug14Moderate
Sep13Moderate
Oct12Moderate
Nov11Good
Dec10Good
Location & terrain

Where is Kai?

Kai sits at 35.7°N, 138.5°E, 340 m above sea level, in Japan. The nearest listed city is Ryūō, 4.0 km away.

Topography around Kai

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

Within 3 km, the terrain around Kai has significant variations in elevation — a maximum elevation change of 349 m around an average of 343 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,154 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,735 m.

The land around Kai is covered by artificial surfaces (51%) and trees (22%) within 3 km, trees (60%) and artificial surfaces (22%) within 16 km, and trees (83%) within 80 km.

3 km
349 m
16 km
2,154 m
80 km
3,735 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Ryūō 4.0 km · Kofu 6.0 km · Nirasaki 6.0 km · Shōwa 7.0 km · Minami-Alps 9.0 km · Minamiarupusu 9.0 km · Chūō 10 km · Isawa 12 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 Kai (35.6846°, 138.5098°, elevation 340 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).