Yōkaichiba weather in May

In May, Yōkaichiba sees average daytime highs of 21°C and overnight lows near 16°C, with 128 mm of rain across 11.7 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 20°C in the first days to 23°C by the end. The sky is clear or mostly clear about 23% of the time in May, and the air most often feels comfortable.

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 Yōkaichiba's 10th-clearest and 4th-windiest month. For the whole year in context, see Yōkaichiba's year-round climate.

Daytime high
21°
5th warmest
Overnight low
16°
7th coldest
Rainfall
128 mm
11.7 wet days
Daylight
13 h 54 min
4:38 AM – 6:30 PM
Cloud cover
69%
10th clearest
Wind
14 km/h
4th windiest
Solar energy
5.44 kWh/m²
Travel score
6.1
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 20°C in the first days to 23°C by the end.

A typical May day in Yōkaichiba reaches about 21°C in the afternoon and slips back to 16°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 25°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)
12014
22014
32014
42014
52014
62014
72115
82115
92115
102115
112115
122115
132115
142115
152116
162116
172216
182216
192216
202216
212216
222216
232217
242217
252217
262317
272317
282317
292317
302317
312317

How May really feels in Yōkaichiba

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.

Yōkaichiba 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 / 828.70.79.92.1
Feb10° / 7790.810.62.3
Mar13° / 13013.10.511.73.4
Apr17° / 11°11212.6012.95.2
May21° / 16°12811.7013.96.1
Jun24° / 19°15913.2014.45.9
Jul28° / 23°14213.3014.25.4
Aug29° / 24°10111.1013.35.1
Sep26° / 22°16814012.25.8
Oct21° / 17°20913.2011.16.1
Nov17° / 11°10910.9010.15.2
Dec12° / 779.409.63.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 12% of May, with mostly cloudy or overcast conditions the remaining 65%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24357
34258
44159
54159
63961
73961
83862
93763
103565
113565
123466
133466
143466
153466
163466
173367
183367
193367
203466
213367
223367
233367
243367
253367
263367
273367
283367
293268
303268
313169

Chance of precipitation in May

Any precipitation

Yōkaichiba gets around 128 mm of rain over 11.7 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 37% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
137
236
336
436
536
636
736
836
936
1036
1137
1237
1337
1437
1538
1638
1738
1838
1938
2038
2139
2239
2339
2439
2538
2638
2738
2838
2938
3038
3138

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the comfortable band about 37% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1632881
2612991
35930101
45731111
55631121
65532121
75333131
85134141
94935152
104736162
114537162
124338172
134138182
144039193
153840193
163641203
173442213
183242223
193042244
202943254
212743264
222542285
232442295
242241315
252140326
262040346
271938367
281837378
291736389
3016353910
3114344011

Wind in May

Winds average 14 km/h in May.

Across May, daily wind ranges from about 13 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

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 4:52 AM to 4:29 AM, and sunset from 6:18 PM to 6:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.44:526:18
213.54:516:19
313.54:506:20
413.54:496:20
513.64:486:21
613.64:476:22
713.64:466:23
813.74:456:24
913.74:446:25
1013.74:436:25
1113.74:426:26
1213.84:416:27
1313.84:406:28
1413.84:396:29
1513.94:386:30
1613.94:386:30
1713.94:376:31
1813.94:366:32
1914.04:356:33
2014.04:356:34
2114.04:346:34
2214.04:336:35
2314.14:336:36
2414.14:326:37
2514.14:326:37
2614.14:316:38
2714.14:316:39
2814.24:306:40
2914.24:306:40
3014.24:296:41
3114.24:296:42

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.44 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.31 kWh/m² to a high of 5.44 kWh/m² in May across the year — May's 5.44 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.4Bright
95.4Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.4Bright
155.4Bright
165.4Bright
175.4Bright
185.4Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in May

Hazard calendar for Yōkaichiba

In seasonPeak

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

Yōkaichiba 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 Yōkaichiba?

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

6.1
Sightseeing
1st-best month of the year
4.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Yōkaichiba for sightseeing.

What to pack for Yōkaichiba in May

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

In May, Yōkaichiba sees daytime highs around 21°C and nights near 16°C. Worth packing: rain gear and sun protection. About 12 days see rain.

rain gearsun protection

Sea temperature near Yōkaichiba 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 25°C and coldest in February near 15°C.

It's comfortable for a long swim from Jun 5 to Nov 22 — about 5.6 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan16Cool
Feb15Bracing
Mar15Cool
Apr16Cool
May19Cool
Jun21Refreshing
Jul23Refreshing
Aug25Warm
Sep25Warm
Oct23Refreshing
Nov21Refreshing
Dec18Cool

UV index in Yōkaichiba in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Yōkaichiba peaks around August 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 highVery highModerateAug 12UV 10Jan 1UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar4Moderate
Apr7High
May8Very high
Jun9Very high
Jul10Very high
Aug10Extreme
Sep8Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Yōkaichiba 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 Yōkaichiba is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (December, 14 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2425 µg/m³Dec 1914 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb18Moderate
Mar25Moderate
Apr25Moderate
May24Moderate
Jun19Moderate
Jul16Moderate
Aug15Moderate
Sep15Moderate
Oct16Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Yōkaichiba?

Yōkaichiba sits at 35.7°N, 140.6°E, 10 m above sea level, in Japan. The nearest listed city is Sōsa, 2.0 km away.

Topography around Yōkaichiba

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

Within 3 km, the terrain around Yōkaichiba has only modest variations in elevation — a maximum elevation change of 53 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 72 m; within 80 km, large variations in elevation — a maximum elevation change of 840 m.

The land around Yōkaichiba is covered by trees (39%), cropland (37%) and artificial surfaces (20%) within 3 km, cropland (31%), trees (30%) and water (22%) within 16 km, and water (42%) and trees (24%) within 80 km.

3 km
53 m
16 km
72 m
80 km
840 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Sōsa 2.0 km · Yokoshiba 8.0 km · Asahi 9.0 km · Sanmu 14 km · Narutō 16 km · Ryōgoku 17 km · Omigawa 18 km · Sawara 21 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 Yōkaichiba (35.7°, 140.55°, elevation 10 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).