Okayama weather in May

In May, Okayama sees average daytime highs of 24°C and overnight lows near 15°C, with 125 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 Okayama's 10th-clearest and 6th-windiest month. For the whole year in context, see Okayama's year-round climate.

Daytime high
24°
5th warmest
Overnight low
15°
8th coldest
Rainfall
125 mm
9.9 wet days
Daylight
13 h 48 min
5:06 AM – 6:55 PM
Cloud cover
63%
10th clearest
Wind
9 km/h
6th windiest
Solar energy
5.74 kWh/m²
Travel score
6.8
out of 10
Air quality
Moderate
PM2.5 11 µg/m³ · 2010

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 22°C in the first days to 25°C by the end.

A typical May day in Okayama reaches about 24°C in the afternoon and slips back to 15°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 28°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)
12213
22213
32313
42313
52313
62314
72314
82314
92314
102314
112414
122414
132415
142415
152415
162415
172415
182415
192415
202516
212516
222516
232516
242516
252516
262516
272517
282517
292517
302617
312617

How May really feels in Okayama

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.

Okayama 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
Jan10° / 405.50.39.92.4
Feb11° / 486.40.610.72.8
Mar14° / 929.30.111.74.3
Apr20° / 10°1089.7012.86.2
May24° / 15°1259.9013.86.8
Jun27° / 20°17212.2014.35.8
Jul31° / 24°18713.6014.14.0
Aug33° / 25°10810.3013.33.6
Sep29° / 21°16810.8012.25.5
Oct23° / 14°1147.7011.17.2
Nov18° / 576.1010.26.2
Dec12° / 465.30.19.73.7

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 58%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34753
44654
54555
64456
74456
84357
94357
104357
114357
124258
134258
144357
154357
164357
174357
184357
194357
204456
214258
224258
234258
244258
254159
264060
274060
283862
293763
303763
313565

Chance of precipitation in May

Any precipitation

Okayama gets around 125 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 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
132
232
332
432
532
633
733
833
934
1034
1134
1234
1334
1434
1534
1633
1733
1832
1932
2032
2131
2231
2330
2430
2529
2629
2729
2828
2928
3028
3129

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 51% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1672292
2672292
3662392
46523102
56424102
66324103
76225103
86026113
96026113
105927113
115827114
125728114
135728114
145529124
155430124
165231134
175231134
185032144
194932154
204733164
214633174
224433194
234234204
244134214
253934234
263734244
273534265
283434275
293234295
303033306
312833317

Wind in May

Winds average 9 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
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 5:20 AM to 4:58 AM, and sunset from 6:43 PM to 7:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:206:43
213.45:196:43
313.45:186:44
413.55:176:45
513.55:166:46
613.55:156:47
713.65:146:48
813.65:136:48
913.65:126:49
1013.65:116:50
1113.75:106:51
1213.75:106:52
1313.75:096:52
1413.85:086:53
1513.85:076:54
1613.85:066:55
1713.85:066:55
1813.95:056:56
1913.95:046:57
2013.95:036:58
2113.95:036:59
2214.05:026:59
2314.05:027:00
2414.05:017:01
2514.05:007:01
2614.05:007:02
2714.14:597:03
2814.14:597:04
2914.14:597:04
3014.14:587:05
3114.14:587:06

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.74 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.41 kWh/m² to a high of 5.74 kWh/m² in May across the year — May's 5.74 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Hazard calendar for Okayama

In seasonPeak

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

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

Okayama'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 Okayama?

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
5.7
Beach & pool
5th-best month of the year

May is a reasonable time to visit Okayama for sightseeing.

What to pack for Okayama in May

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

In May, Okayama sees daytime highs around 24°C and nights near 15°C. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

Sea temperature near Okayama in May

The nearest coast averages about 17°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 41 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 7 to Nov 12 — about 5.2 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb13Bracing
Mar13Bracing
Apr15Bracing
May17Cool
Jun21Refreshing
Jul25Warm
Aug27Warm
Sep26Warm
Oct24Refreshing
Nov20Cool
Dec16Cool

UV index in Okayama 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 Okayama peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 highModerateJul 13UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Okayama 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 Okayama is worst in April — around 15 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (October, 8 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Okayama's WHO annual average of 11 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1415 µg/m³Oct 168 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar14Moderate
Apr15Moderate
May14Moderate
Jun12Moderate
Jul10Good
Aug10Good
Sep9Good
Oct8Good
Nov9Good
Dec9Good
Location & terrain

Where is Okayama?

Okayama sits at 34.6°N, 133.9°E, 5 m above sea level, in Japan. The nearest listed city is Tamano, 15 km away.

Topography around Okayama

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

Within 3 km, the terrain around Okayama has only modest variations in elevation — a maximum elevation change of 171 m around an average of 13 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 503 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,811 m.

The land around Okayama is covered by artificial surfaces (79%) within 3 km, trees (41%) and artificial surfaces (26%) within 16 km, and trees (61%) and water (26%) within 80 km.

3 km
171 m
16 km
503 m
80 km
1,811 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Tamano 15 km · Sōja 17 km · Kurashiki 17 km · Setouchi 19 km · Akaiwa 20 km · Naoshima 22 km · Bizen 32 km · Takahashi 33 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 Okayama (34.65°, 133.9333°, elevation 5 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).