Climate and average weather in Sukumo

In Sukumo, the summers are muggy, hot, wet, and partly cloudy and the winters are cool and partly cloudy.

Best: late September to late November

Over the course of the year, the temperature in Sukumo typically varies from 5°C to 30°C, and is rarely below 1°C or above 33°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Sukumo for warm-weather activities are from early April to mid June and late September to late November.

Hottest
Aug
30°
Coldest
Jan
Wettest
Jun
328 mm
Driest
Jan
66 mm
Rain / yr
2017 mm
137 wet days
Daylight
9.8–14.2 h
shortest–longest
Elevation
12 m
32.9°N
Clearest
Nov
47% cloud

Sukumo is city in Kōchi Prefecture, Japan.

Density
67/km²
people per km²
Founded
1954

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Sukumo weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late September to late November.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Sukumo, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 3.6 months, from June 16 to October 2, with daily high temperatures above 25°C. The hottest month of the year in Sukumo is August, with an average high of 30°C and low of 25°C.

The cool season lasts 3.1 months, from December 7 to March 11, with daily high temperatures below 14°C. The coldest month of the year in Sukumo is January, with an average low of 5°C and high of 11°C.

Days typically run about 6°C warmer than nights year-round.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan115
Feb125
Mar158
Apr1912
May2316
Jun2520
Jul2924
Aug3025
Sep2822
Oct2317
Nov1812
Dec137

How hot and cold Sukumo really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Sukumo feels like about 36°C (around August 4). About 56 days a year carry some heat stress, peaking in August.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan111115
Feb121225
Mar151558
Apr19191212
May23231616
Jun25252020
Jul33292424
Aug35302525
Sep29282222
Oct23231717
Nov18181112
Dec131347

Average hourly temperature in Sukumo

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on August afternoons, near 30°C, and coldest before dawn in January, near C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Sukumo weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan11° / 666.310.12.8
Feb12° / 848.210.83.1
Mar15° / 13611.311.74.4
Apr19° / 12°1601112.86.0
May23° / 16°1891213.76.4
Jun25° / 20°32816.614.15.4
Jul29° / 24°25215.8144.6
Aug30° / 25°19215.413.24.4
Sep28° / 22°23914.912.25.4
Oct23° / 17°18310.111.27.0
Nov18° / 12°1088.710.36.1
Dec13° / 806.79.94.1

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Sukumo gets about 2017 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.4 months, from around May 26 to Oct 7, peaking in June at about 64% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 1.

June is the wettest month by volume, with 328 mm over about 17 wet days; January is the driest, with 66 mm.

0%10%20%30%40%50%60%70%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 24 · 64%Jan 1 · 18%
Rain on a day (%)Rain days
Jan216
Feb298
Mar3611
Apr3711
May3812
Jun5517
Jul5116
Aug5015
Sep4915
Oct3310
Nov299
Dec217

Monthly rainfall

Over a full year, Sukumo collects about 2017 mm of rain across 137 wet days — roughly 168 mm in an average month.

It doesn’t fall evenly. June is the wettest month with 328 mm, while January is the driest at just 66 mm. The three wettest months alone bring about 41% of the year’s total.

050100150200250300350400JanFebMarAprMayJunJulAugSepOctNovDec668413616018932825219223918310880
Rainfall (mm)Rain days
Jan666
Feb848
Mar13611
Apr16011
May18912
Jun32817
Jul25216
Aug19215
Sep23915
Oct18310
Nov1089
Dec807

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Sukumo, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around September 23 and lasts for 6.6 months, ending around April 10. The clearest month is December, when the sky is clear, mostly clear, or partly cloudy 61% of the time on average.

The cloudier part of the year begins around April 11 and lasts for 5.4 months, ending around September 22. The cloudiest month is June, when it is overcast or mostly cloudy 78% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecJan 1 · 63%Jun 24 · 18%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan5644
Feb5644
Mar5149
Apr4753
May3763
Jun2278
Jul3169
Aug4456
Sep4654
Oct5842
Nov6139
Dec6139

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 15, brings about 14 h 12 min of light; the shortest, around December 14, only 9 h 48 min — a swing of roughly 4 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan10.17:175:20
Feb10.87:005:47
Mar11.76:266:11
Apr12.85:456:34
May13.75:156:56
Jun14.15:057:14
Jul14.05:157:14
Aug13.25:366:50
Sep12.25:576:09
Oct11.26:195:29
Nov10.36:465:03
Dec9.97:105:00

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Sukumo averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 15 days.

The sunnier stretch runs 3.7 months, from around Sep 25 to Jan 14. The sunniest month is October, with roughly 14 sunny days (mixed).

The greyest month is June, down near 4 sunny days — about 73% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergloomymixedbrightOct 2315 daysJun 203 days
Sunny daysSky
Jan11Mixed
Feb11Mixed
Mar12Mixed
Apr11Mixed
May8Mixed
Jun4Gloomy
Jul6Gloomy
Aug9Mixed
Sep10Mixed
Oct14Mixed
Nov14Mixed
Dec13Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Sukumo, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.8 months, from around May 22 to October 14. The muggiest month is July, when the air feels humid, muggy or worse about 100% of the time.

The most comfortable stretch runs from around October 15 to May 21, and February is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecFeb 5 · 100%Jul 5 · 0%miserablemuggydryhumidoppressivecomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan9910000
Feb9820000
Mar9451000
Apr72188200
May3332241110
Jun292835223
Jul001145729
Aug00175140
Sep3817263611
Oct3525211450
Nov77138200
Dec9730000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Sukumo is typically light breeze, near 13 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.3 months, from around Nov 15 to Apr 23. The windiest month is January, averaging about 16 km/h (light breeze).

The calmer part of the year runs from around Apr 24 to Nov 14, with September the calmest month at about 11 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeJan 7 · 16 km/hSep 1 · 10 km/h
Wind speed (km/h)Feels
Jan16light breeze
Feb16light breeze
Mar14light breeze
Apr13light breeze
May12calm
Jun11calm
Jul11calm
Aug11calm
Sep11calm
Oct11calm
Nov13light breeze
Dec15light breeze

Hazard calendar for Sukumo

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

Sukumo's rainy season runs April–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

Best time to visit Sukumo

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Sukumo throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid November, Sukumo is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best times of year to visit Sukumo for general outdoor tourist activities run from early April to mid June and again from late September to late November, with a peak score in the third week of October.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationOct 18 · 7.2

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan2.8poor
Feb3.1poor
Mar4.4fair
Apr5.9good
May6.4good
Jun5.4fair
Jul4.6fair
Aug4.4fair
Sep5.5fair
Oct6.9good
Nov6.1good
Dec4.1fair

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Sukumo for hot-weather activities is from mid May to late October, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 23 · 6.0

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Sukumo, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around August (highs near 30°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 11°C), pack a warm layer.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Sukumo sees daytime highs around 30°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.

Sea temperature near Sukumo

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea offshore is warmest in August at about 28°C and coldest in February near 18°C.

It's comfortable for a long swim from May 1 to Dec 23 — about 7.8 months when the water holds above 20°C.

15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan19Cool
Feb18Cool
Mar18Cool
Apr19Cool
May21Refreshing
Jun23Refreshing
Jul26Warm
Aug28Warm
Sep27Warm
Oct25Warm
Nov23Refreshing
Dec20Refreshing

UV index (midday) in Sukumo by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Sukumo peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJun 23UV 11Dec 23UV 3
UV index (midday)Level
Jan3Moderate
Feb5Moderate
Mar6High
Apr7Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug10Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec3Moderate

Average hourly UV index in Sukumo

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan1.50
Feb4.50
Mar61
Apr73.5
May7.54.5
Jun8.56
Jul8.56
Aug85.5
Sep7.55
Oct5.52
Nov3.50
Dec10

Air quality in Sukumo by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Sukumo is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1420 µg/m³Oct 1410 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb15Moderate
Mar19Moderate
Apr20Moderate
May18Moderate
Jun15Moderate
Jul11Good
Aug11Good
Sep10Good
Oct10Good
Nov11Good
Dec10Good
Almanac & agriculture

Growing season

Chance of a frost-free day

Sukumo is mild enough that a frost-free day stays more likely than not even in midwinter.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDec
Frost-free chance (%)Frost nights
Jan960
Feb940
Mar980
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec990

Growing degree days

Degree days (base 10°C)

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Sukumo banks about 2,847 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar41
Apr170
May296
Jun382
Jul510
Aug538
Sep441
Oct311
Nov145
Dec14

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Sukumo receives about 4.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.6 and 5.5 kWh/m².

The brighter stretch of the year lasts 6.5 months, from around Mar 7 to Sep 20. The brightest month is May, averaging about 5.4 kWh/m² (bright).

The dimmest month is December, down near 2.6 kWh/m² — roughly 52% less than the May peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseMay 185.5 kWhDec 142.6 kWh
Solar energy (kWh/m²)Level
Jan2.8Moderate
Feb3.6Moderate
Mar4.4Bright
Apr5.3Bright
May5.5Bright
Jun4.7Bright
Jul5.3Bright
Aug5.2Bright
Sep4.3Bright
Oct3.7Moderate
Nov2.9Moderate
Dec2.6Moderate

Where is Sukumo?

Sukumo sits at 32.9°N, 132.7°E, 12 m above sea level, in Japan. The nearest listed city is Mishōhirajō, 16 km away.

Topography around Sukumo

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

Within 3 km, the terrain around Sukumo has significant variations in elevation — a maximum elevation change of 454 m around an average of 116 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,052 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,528 m.

The land around Sukumo is covered by trees (76%) within 3 km, trees (79%) within 16 km, and water (62%) and trees (36%) within 80 km.

3 km
454 m
16 km
1,052 m
80 km
1,528 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Mishōhirajō 16 km · Nakamura 19 km · Shimoda 24 km · Uwajima 36 km · Uwa 52 km · Yawatahama 65 km · Ōzu 65 km · Uchiko 69 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 Sukumo (32.9333°, 132.7333°, elevation 12 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).