Rittō weather in May

In May, Rittō sees average daytime highs of 23°C and overnight lows near 13°C, with 138 mm of rain across 10.7 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 21°C in the first days to 24°C by the end. The sky is clear or mostly clear about 25% 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 Rittō's 10th-clearest and 5th-windiest month. For the whole year in context, see Rittō's year-round climate.

Daytime high
23°
5th warmest
Overnight low
13°
8th coldest
Rainfall
138 mm
10.7 wet days
Daylight
13 h 48 min
4:57 AM – 6:47 PM
Cloud cover
67%
10th clearest
Wind
9 km/h
5th windiest
Solar energy
5.41 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 21°C in the first days to 24°C by the end.

A typical May day in Rittō reaches about 23°C in the afternoon and slips back to 13°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 18°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)
12111
22111
32112
42112
52112
62212
72212
82212
92212
102213
112213
122213
132213
142213
152313
162313
172314
182314
192314
202314
212314
222414
232415
242415
252415
262415
272415
282415
292415
302516
312516

How May really feels in Rittō

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.

Rittō 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 daysSnow daysDaylight (hours)Travel score
Jan / 618.32.59.91.2
Feb / 6492.510.71.6
Mar12° / 11012.20.611.73.2
Apr18° / 11911012.95.5
May23° / 13°13810.7013.86.5
Jun26° / 18°17712.9014.35.8
Jul30° / 23°18214.8014.14.3
Aug32° / 24°10311.1013.34.0
Sep28° / 20°15311.5012.25.8
Oct22° / 13°1489.6011.16.7
Nov16° / 746.8010.25.3
Dec10° / 587.71.19.72.5

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% 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 63%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24159
34159
44159
54159
64060
74060
83961
93862
103862
113763
123763
133763
143763
153763
163763
173763
183763
193763
203664
213664
223664
233664
243664
253664
263466
273367
283367
293367
303268
313268

Chance of precipitation in May

Any precipitation

Rittō gets around 138 mm of rain over 10.7 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 34% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
134
234
334
434
534
635
735
836
936
1037
1137
1237
1337
1437
1537
1637
1737
1836
1935
2035
2134
2234
2333
2432
2531
2631
2730
2829
2929
3029
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 60% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1801550
2781651
3761761
4761761
5751861
6731971
7722071
8722071
9702181
10692281
11692281
12682381
13662491
14652591
15642691
16632791
17622891
186029101
195930101
205731111
215532112
225333122
235134132
244935132
254736142
264538152
274339163
284140173
293941183
303641193
313442213

Wind in May

Winds average 9 km/h in May.

Across May, daily wind ranges from about 9 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
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

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 5:11 AM to 4:49 AM, and sunset from 6:35 PM to 6:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:116:35
213.45:106:36
313.55:096:37
413.55:086:37
513.55:076:38
613.55:066:39
713.65:056:40
813.65:046:41
913.65:036:42
1013.75:026:42
1113.75:016:43
1213.75:016:44
1313.85:006:45
1413.84:596:46
1513.84:586:46
1613.84:576:47
1713.94:576:48
1813.94:566:49
1913.94:556:50
2013.94:546:50
2114.04:546:51
2214.04:536:52
2314.04:526:53
2414.04:526:53
2514.04:516:54
2614.14:516:55
2714.14:506:55
2814.14:506:56
2914.14:496:57
3014.14:496:58
3114.24:496:58

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.41 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.23 kWh/m² to a high of 5.41 kWh/m² in May across the year — May's 5.41 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
305.5Bright
315.4Bright
Planning a trip in May

Hazard calendar for Rittō

In seasonPeak

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

Rittō 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 Rittō?

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
4.9
Beach & pool
5th-best month of the year

May is a reasonable time to visit Rittō for sightseeing.

What to pack for Rittō in May

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

In May, Rittō sees daytime highs around 23°C and nights near 13°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Rittō 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 59 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 May 31 to Nov 9 — 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
Mar14Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul26Warm
Aug27Warm
Sep26Warm
Oct22Refreshing
Nov19Cool
Dec16Cool

UV index in Rittō 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 Rittō peaks around July 14 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 14UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar5High
Apr7High
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep9Very high
Oct6High
Nov3Moderate
Dec2Moderate

Air quality in Rittō 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 Rittō is worst in April — around 24 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1723 µg/m³Oct 1812 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb17Moderate
Mar22Moderate
Apr24Moderate
May22Moderate
Jun19Moderate
Jul17Moderate
Aug17Moderate
Sep14Moderate
Oct12Good
Nov13Moderate
Dec12Moderate
Location & terrain

Where is Rittō?

Rittō sits at 35.0°N, 136.0°E, 107 m above sea level, in Japan. The nearest listed city is Kusatsu, 3.0 km away.

Topography around Rittō

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

Within 3 km, the terrain around Rittō has only modest variations in elevation — a maximum elevation change of 138 m around an average of 113 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 778 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,416 m.

The land around Rittō is covered by artificial surfaces (62%) within 3 km, trees (43%) and artificial surfaces (23%) within 16 km, and trees (59%) within 80 km.

3 km
138 m
16 km
778 m
80 km
1,416 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Kusatsu 3.0 km · Moriyama 5.0 km · Yasu 8.0 km · Konan 9.0 km · Ōtsu 12 km · Ōmihachiman 14 km · Kōka 15 km · Minakuchichō-matoba 17 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 Rittō (35.0275°, 135.9997°, elevation 107 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).