Kōzan weather in May

In May, Kōzan sees average daytime highs of 23°C and overnight lows near 14°C, with 129 mm of rain across 9.9 wet days and about 13.8 hours of daylight. It is the 5th-warmest and 4th-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 29% 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 Kōzan's 10th-clearest and 8th-windiest month. For the whole year in context, see Kōzan's year-round climate.

Daytime high
23°
5th warmest
Overnight low
14°
8th coldest
Rainfall
129 mm
9.9 wet days
Daylight
13 h 48 min
5:10 AM – 6:58 PM
Cloud cover
63%
10th clearest
Wind
8 km/h
8th windiest
Solar energy
5.56 kWh/m²
Travel score
6.8
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 Kōzan reaches about 23°C in the afternoon and slips back to 14°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 27°C. Set against its neighbours, May runs about 5°C warmer than April and about 3°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12212
22212
32212
42212
52213
62213
72313
82313
92313
102313
112313
122314
132314
142314
152314
162414
172414
182414
192415
202415
212415
222415
232415
242415
252415
262515
272516
282516
292516
302516
312516

How May really feels in Kōzan

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.

Kōzan weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 435.419.91.8
Feb10° / 547.21.410.72.2
Mar14° / 959.90.411.73.9
Apr19° / 1109.7012.86.0
May23° / 14°1299.9013.86.8
Jun26° / 19°19212.8014.35.8
Jul30° / 23°20713.7014.14.4
Aug32° / 24°12512.2013.33.9
Sep28° / 20°16011012.25.7
Oct22° / 13°1037.6011.17.2
Nov17° / 596.6010.25.7
Dec11° / 505.90.49.73.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 13% of May, with mostly cloudy or overcast conditions the remaining 59%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14654
24555
34555
44456
54456
64357
74357
84258
94159
104159
114159
124159
134159
144159
154159
164258
174258
184258
194258
204258
214258
224258
234159
244159
254159
264159
274060
283961
293862
303664
313565

Chance of precipitation in May

Any precipitation

Kōzan gets around 129 mm of rain over 9.9 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 32% and peaks near 33% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
330
431
531
632
732
833
933
1033
1133
1233
1333
1433
1533
1632
1732
1831
1931
2031
2131
2231
2331
2431
2531
2631
2731
2831
2931
3031
3132

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 58% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1761761
2751861
3741871
4731971
5712072
6702172
7692272
8682282
9672382
10672382
11662482
12652582
13652582
14642682
15622792
16612892
17602992
185929102
195730112
205631112
215432122
225233132
235034142
244835152
254636162
264436172
274237183
283938203
293739213
303439234
313240244

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

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 5:24 AM to 5:01 AM, and sunset from 6:46 PM to 7:09 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:246:46
213.45:236:47
313.45:226:48
413.55:216:49
513.55:206:49
613.55:196:50
713.65:186:51
813.65:176:52
913.65:166:53
1013.65:156:53
1113.75:146:54
1213.75:136:55
1313.75:126:56
1413.75:126:57
1513.85:116:57
1613.85:106:58
1713.85:096:59
1813.95:097:00
1913.95:087:00
2013.95:077:01
2113.95:077:02
2213.95:067:03
2314.05:057:03
2414.05:057:04
2514.05:047:05
2614.05:047:06
2714.15:037:06
2814.15:037:07
2914.15:027:08
3014.15:027:08
3114.15:017:09

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.56 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.24 kWh/m² to a high of 5.56 kWh/m² in May across the year — May's 5.56 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
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.6Bright
195.6Bright
205.6Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.5Bright
295.5Bright
305.5Bright
315.5Bright
Planning a trip in May

Hazard calendar for Kōzan

In seasonPeak

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

Kōzan sits in the Pacific typhoon belt; the season peaks July–October.

Kōzan's rainy season runs March–October, when most of the year's rain falls.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Kōzan?

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

6.8
Sightseeing
2nd-best month of the year
5.4
Beach & pool
5th-best month of the year

May is a reasonable time to visit Kōzan for sightseeing.

What to pack for Kōzan in May

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

In May, Kōzan sees daytime highs around 23°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

Sea temperature near Kōzan in May

The nearest coast averages about 18°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 38 km away) is warmest in August at about 27°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 3 to Nov 12 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul25Warm
Aug27Warm
Sep27Warm
Oct23Refreshing
Nov20Cool
Dec16Cool

UV index in Kōzan 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 Kōzan peaks around July 15 at about 10 (extreme) — 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 highExtremeVery highModerateJul 15UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Kōzan 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 Kōzan is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1322 µg/m³Oct 1711 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb17Moderate
Mar21Moderate
Apr22Moderate
May20Moderate
Jun18Moderate
Jul14Moderate
Aug14Moderate
Sep12Good
Oct11Good
Nov12Good
Dec11Good
Location & terrain

Where is Kōzan?

Kōzan sits at 34.6°N, 133.1°E, 337 m above sea level, in Japan. The nearest listed city is Fuchūchō, 17 km away.

Topography around Kōzan

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

Within 3 km, the terrain around Kōzan has significant variations in elevation — a maximum elevation change of 315 m around an average of 432 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 710 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,264 m.

The land around Kōzan is covered by trees (72%) within 3 km, trees (85%) within 16 km, and trees (68%) and water (22%) within 80 km.

3 km
315 m
16 km
710 m
80 km
1,264 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Fuchūchō 17 km · Mihara 21 km · Shin’ichi 21 km · Onomichi 23 km · Shōbara 30 km · Takehara 30 km · Miyoshi 30 km · Fukuyama 31 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 Kōzan (34.5833°, 133.05°, elevation 337 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).