Climate and average weather in Ishikari

In Ishikari, the summers are humid, warm, showery, and partly cloudy and the winters are very cold, snowy, and mostly cloudy.

Best: early June to early October

Over the course of the year, the temperature in Ishikari typically varies from -6°C to 24°C, and is rarely below -10°C or above 27°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Ishikari for warm-weather activities is from early June to early October.

Hottest
Aug
24°
Coldest
Jan
-6°
Wettest
Aug
167 mm
Driest
Mar
62 mm
Rain / yr
1176 mm
171 wet days
Daylight
8.8–15.2 h
shortest–longest
Elevation
0 m
43.2°N
Clearest
Apr
56% cloud

Ishikari 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 early June to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.8 months, from June 11 to October 3, with daily high temperatures above 18°C. The hottest month of the year in Ishikari is August, with an average high of 24°C and low of 19°C.

The cool season lasts 3.6 months, from December 3 to March 20, with daily high temperatures below 3°C. The coldest month of the year in Ishikari is January, with an average low of -6°C and high of -2°C.

Days typically run about 5°C warmer than nights year-round.

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan-2-6
Feb-1-6
Mar3-3
Apr92
May148
Jun1813
Jul2218
Aug2419
Sep2116
Oct1510
Nov83
Dec1-3

How hot and cold Ishikari 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 coldest nights, wind chill pulls the feels-like down to about -13°C (around January 28), with roughly 162 freezing days a year (feels-like at or below 0°C) 66 of them bitterly cold — worst in January.

-10°10°20°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan-2-2-12-6
Feb-1-1-12-6
Mar33-8-3
Apr99-12
May141468
Jun18181313
Jul22221818
Aug24241919
Sep21211616
Oct1515810
Nov88-13
Dec11-8-3

Average hourly temperature in Ishikari

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 24°C, and coldest before dawn in January, near -6°C.

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

Ishikari weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -6°8019.222.59.20.0
Feb-1° / -6°6416.118.410.20.0
Mar / -3°6212.51211.60.0
Apr / 6310.92.613.21.6
May14° / 83110.114.54.0
Jun18° / 13°7410.1015.15.7
Jul22° / 18°12712.2014.96.2
Aug24° / 19°16713.2013.86.3
Sep21° / 16°13913.4012.35.9
Oct15° / 10°10113.90.210.84.2
Nov / 11117.77.49.51.0
Dec / -3°10420.320.48.90.0

Chance of rain

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

Ishikari gets about 1176 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.1 months, from around Oct 29 to Mar 3, peaking in December at about 66% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 22.

August is the wettest month by volume, with 167 mm over about 13 wet days; March is the driest, with 62 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%70%80%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetDec 18 · 66%Jun 22 · 32%
Rain on a day (%)Rain days
Jan6319
Feb5816
Mar4113
Apr3611
May3611
Jun3410
Jul3812
Aug4313
Sep4513
Oct4514
Nov5818
Dec6520

Monthly rainfall

Over a full year, Ishikari collects about 1176 mm of rain across 171 wet days — roughly 98 mm in an average month.

It doesn’t fall evenly. August is the wettest month with 167 mm, while March is the driest at just 62 mm. The three wettest months alone bring about 37% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100125150175200JanFebMarAprMayJunJulAugSepOctNovDec806462638374127167139101111104
Rainfall (mm)Rain daysSnow days
Jan801923
Feb641618
Mar621312
Apr63113
May83110
Jun74100
Jul127120
Aug167130
Sep139130
Oct101140
Nov111187
Dec1042020

Snow in Ishikari

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Ishikari averages about 84 snowy days a year. Snow season runs roughly Oct 24 to May 1 — about 6.2 months.

January is snowiest, with roughly 22 days of snow and an estimated 89 cm of snowfall. Over the year that adds up to an estimated 348 cm of snow.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 5
Snow daysSnowfall (cm)
Jan2389
Feb1880
Mar1241
Apr39
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov736
Dec2093

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Ishikari, 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 August 31 and lasts for 2.6 months, ending around November 16. The clearest month is October, when the sky is clear, mostly clear, or partly cloudy 56% of the time on average.

The cloudier part of the year begins around November 17 and lasts for 3.7 months, ending around March 10. The cloudiest month is January, when it is overcast or mostly cloudy 73% 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%JanFebMarAprMayJunJulAugSepOctNovDecOct 19 · 59%Feb 1 · 25%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2773
Feb3070
Mar4555
Apr5149
May4456
Jun3961
Jul3664
Aug3961
Sep4555
Oct5644
Nov4258
Dec3268

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 13, brings about 15 h 12 min of light; the shortest, around January 1, only 8 h 48 min — a swing of roughly 6 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.27:104:18
Feb10.26:424:56
Mar11.65:555:33
Apr13.24:596:10
May14.54:166:45
Jun15.13:597:10
Jul14.94:137:07
Aug13.84:456:32
Sep12.35:205:38
Oct10.85:564:43
Nov9.56:364:04
Dec8.97:063:55

Sunny days

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

Ishikari averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 11 days.

The sunnier stretch runs 3.7 months, from around Mar 15 to Jul 4. The sunniest month is April, with roughly 10 sunny days (mixed).

The greyest month is January, down near 2 sunny days — about 86% fewer than the April peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedApr 1711 daysJan 191 days
Sunny daysSky
Jan2Gloomy
Feb2Gloomy
Mar7Gloomy
Apr10Mixed
May10Mixed
Jun8Gloomy
Jul6Gloomy
Aug7Gloomy
Sep9Mixed
Oct9Mixed
Nov5Gloomy
Dec2Gloomy

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 Ishikari, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 3.1 months, from around June 21 to September 22. The muggiest month is August, when the air feels humid, muggy or worse about 85% of the time.

The most comfortable stretch runs from around September 23 to June 20, and May 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%JanFebMarAprMayJunJulAugSepOctNovDecMay 25 · 100%Aug 8 · 11%oppressivemuggycomfortablehumiddrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar1000000
Apr1000000
May982000
Jun51361210
Jul62340256
Aug313313716
Sep333221112
Oct909100
Nov1000000
Dec1000000

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 Ishikari is typically light breeze, near 14 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.9 months, from around Oct 3 to Mar 31. The windiest month is December, averaging about 18 km/h (light breeze).

The calmer part of the year runs from around Apr 1 to Oct 2, with July the calmest month at about 11 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyDec 4 · 19 km/hJul 10 · 10 km/h
Wind speed (km/h)Feels
Jan17light breeze
Feb16light breeze
Mar15light breeze
Apr14light breeze
May13light breeze
Jun11calm
Jul11calm
Aug11calm
Sep13light breeze
Oct16light breeze
Nov18light breeze
Dec18light breeze

Hazard calendar for Ishikari

In seasonPeak

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

Ishikari 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

Best time to visit Ishikari

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late September, Ishikari 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 time of year to visit Ishikari for general outdoor tourist activities is from early June to early October, with a peak score in the last week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 30 · 6.4

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
Jan0.0poor
Feb0.0poor
Mar0.0poor
Apr1.6poor
May4.0fair
Jun5.7good
Jul6.2good
Aug6.3good
Sep5.8good
Oct4.2fair
Nov1.1poor
Dec0.0poor

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 Ishikari for hot-weather activities is from mid July to early September, with a peak score in the first week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 6 · 5.4

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 Ishikari, 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 24°C), the essentials are light clothes and rain gear. In the cold season around January (highs near -2°C), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Ishikari sees daytime highs around 24°C and nights near 19°C. Worth packing: light clothes and rain gear. About 13 days see rain.

Sea temperature near Ishikari

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

The sea at the nearest coast (about 15 km away) is warmest in August at about 22°C and coldest in February near 5°C.

It's comfortable for a long swim from Jul 31 to Sep 22 — about 1.8 months when the water holds above 20°C.

10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan7Bracing
Feb5Bracing
Mar5Bracing
Apr7Bracing
May10Bracing
Jun14Bracing
Jul19Cool
Aug22Refreshing
Sep21Refreshing
Oct17Cool
Nov13Bracing
Dec9Bracing

UV index (midday) in Ishikari 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 Ishikari peaks around August 18 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighHighVery highHighModerateLowAug 18UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5High
May7Very high
Jun7High
Jul5Moderate
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Average hourly UV index in Ishikari

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 August the burn window is concentrated in the middle of the day: about 7.5 hours a day reach index 3 (protection recommended), and 4.5 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)
Jan00
Feb00
Mar20
Apr60
May7.54
Jun7.52.5
Jul60
Aug7.54.5
Sep61
Oct30
Nov00
Dec00

Air quality in Ishikari 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 Ishikari is worst in April — around 21 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (December, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1121 µg/m³Dec 169 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb15Moderate
Mar21Moderate
Apr21Moderate
May19Moderate
Jun13Moderate
Jul12Moderate
Aug11Good
Sep10Good
Oct12Good
Nov11Good
Dec9Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Ishikari typically lasts about 241 days, from around April 3 to November 29 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 19 to November 12.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 1210%Apr 350%Apr 1990%Nov 1290%Nov 2950%Dec 1910%
Frost-free chance (%)Frost nights
Jan231
Feb228
Mar1831
Apr7918
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov8117
Dec1731

Growing degree days

Degree days (base 10°C)Frost-free shaded

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. Ishikari banks about 1,200 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

05001,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr0
May40
Jun171
Jul305
Aug358
Sep252
Oct73
Nov0
Dec0

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.

Ishikari receives about 3.7 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.5 and 5.6 kWh/m².

The brighter stretch of the year lasts 6.5 months, from around Mar 4 to Sep 16. The brightest month is May, averaging about 5.5 kWh/m² (bright).

The dimmest month is December, down near 1.5 kWh/m² — roughly 72% less than the May peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseMay 305.6 kWhDec 101.5 kWh
Solar energy (kWh/m²)Level
Jan1.9Dim
Feb2.9Moderate
Mar4.3Bright
Apr5.2Bright
May5.5Bright
Jun5.4Bright
Jul5.0Bright
Aug4.4Bright
Sep3.8Moderate
Oct2.8Moderate
Nov1.8Dim
Dec1.5Dim

Where is Ishikari?

Ishikari sits at 43.2°N, 141.4°E, 0 m above sea level, in Japan. The nearest listed city is Tōbetsu, 13 km away.

Topography around Ishikari

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

Within 3 km, the terrain around Ishikari has only modest variations in elevation — a maximum elevation change of 14 m around an average of 3 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 414 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,859 m.

The land around Ishikari is covered by water (43%) and cropland (26%) within 3 km, water (45%) and cropland (20%) within 16 km, and trees (57%) and water (26%) within 80 km.

3 km
14 m
16 km
414 m
80 km
1,859 m
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Tōbetsu 13 km · Sapporo 19 km · Ebetsu 22 km · Otaru 29 km · Iwamizawa 33 km · Kitahiroshima 34 km · Bibai 42 km · Eniwa 43 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 Ishikari (43.2397°, 141.3539°, elevation 0 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).