Isawa weather in May

In May, Isawa sees average daytime highs of 18°C and overnight lows near 9°C, with 147 mm of precipitation across 15.1 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 19°C by the end. The sky is clear or mostly clear about 19% 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 Isawa's 8th-clearest and 6th-windiest month. For the whole year in context, see Isawa's year-round climate.

Daytime high
18°
5th warmest
Overnight low
8th coldest
Precipitation
147 mm
15.1 wet days
Daylight
13 h 54 min
4:45 AM – 6:38 PM
Cloud cover
71%
8th clearest
Wind
5 km/h
6th windiest
Solar energy
5.33 kWh/m²
Travel score
5.1
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 19°C by the end.

A typical May day in Isawa reaches about 18°C in the afternoon and slips back to 9°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 13°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)
1167
2177
3177
4177
5177
6177
7178
8178
9188
10188
11188
12188
13189
14189
15189
16189
17189
18189
19199
201910
211910
221910
231910
241910
251910
261910
271911
281911
291911
301911
312011

How May really feels in Isawa

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.

Isawa 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 / -6°6676.59.90.0
Feb / -6°718.46.610.70.0
Mar / -2°12913.57.911.71.0
Apr13° / 13113.92.212.93.5
May18° / 14715.10.213.95.1
Jun21° / 14°20519.8014.44.6
Jul25° / 18°23421.9014.24.8
Aug26° / 18°18921.7013.34.9
Sep22° / 15°22018.6012.25.1
Oct16° / 21215.5011.14.5
Nov11° / 8810.10.510.12.8
Dec / -3°607.64.19.60.4

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 67%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24258
34060
44060
53961
63961
73763
83763
93565
103565
113565
123466
133367
143367
153367
163268
173268
183268
193169
203169
213070
223070
232971
242971
252971
262872
272872
282773
292773
302575
312575

Chance of precipitation in May

Any precipitation

Isawa gets around 147 mm of rain and snow over 15.1 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 48% and peaks near 53% on the wettest days, and about 0 day brings snow. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
143
243
343
444
544
645
745
846
947
1047
1148
1248
1349
1449
1549
1650
1750
1850
1950
2050
2150
2250
2350
2450
2551
2651
2751
2851
2952
3052
3153

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 95% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19910
29910
39910
49820
59820
69820
79820
89721
99631
109631
119631
129631
139541
149541
159541
169541
179541
189451
199451
209451
219361
229361
239361
249271
259271
269271
279181
289181
299091
3089101
3188111

Wind in May

Winds average 5 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
135calm
145calm
155calm
165calm
175calm
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 6:25 PM to 6:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:006:25
213.54:596:26
313.54:586:27
413.54:576:28
513.64:566:29
613.64:556:30
713.64:546:31
813.64:536:31
913.74:526:32
1013.74:516:33
1113.74:506:34
1213.84:496:35
1313.84:486:36
1413.84:476:36
1513.84:466:37
1613.94:456:38
1713.94:456:39
1813.94:446:40
1914.04:436:40
2014.04:426:41
2114.04:426:42
2214.04:416:43
2314.04:416:43
2414.14:406:44
2514.14:396:45
2614.14:396:46
2714.14:386:46
2814.24:386:47
2914.24:376:48
3014.24:376:49
3114.24:376:49

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.33 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.57 kWh/m² to a high of 5.33 kWh/m² in May across the year — May's 5.33 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
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.4Bright
205.4Bright
215.4Bright
225.4Bright
235.4Bright
245.4Bright
255.4Bright
265.3Bright
275.3Bright
285.3Bright
295.3Bright
305.3Bright
315.2Bright
Planning a trip in May

Is May a good time to visit Isawa?

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

5.1
Sightseeing
1st-best month of the year
1.8
Beach & pool
5th-best month of the year

May is a reasonable time to visit Isawa for sightseeing.

What to pack for Isawa in May

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

In May, Isawa sees daytime highs around 18°C and nights near 9°C. Pack rain gear. Worth having: sun protection. About 15 days see rain.

rain gearsun protection

Sea temperature near Isawa 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 58 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 Isawa 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 Isawa peaks around July 16 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 highExtremeVery highModerateJul 16UV 10Dec 23UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Very high
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec2Moderate

Air quality in Isawa 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 Isawa 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 Isawa?

Isawa sits at 35.6°N, 138.6°E, 269 m above sea level, in Japan. The nearest listed city is Fuefuki, 2.0 km away.

Topography around Isawa

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

Within 3 km, the terrain around Isawa has significant variations in elevation — a maximum elevation change of 519 m around an average of 308 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,549 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,735 m.

The land around Isawa is covered by artificial surfaces (46%), cropland (28%) and trees (22%) within 3 km, trees (63%) and artificial surfaces (20%) within 16 km, and trees (77%) within 80 km.

3 km
519 m
16 km
1,549 m
80 km
3,735 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Fuefuki 2.0 km · Kofu 6.0 km · Yamanashi 6.0 km · Shōwa 9.0 km · Enzan 11 km · Kai 12 km · Ryūō 12 km · Chūō 13 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 Isawa (35.65°, 138.6333°, elevation 269 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).