Sapporo weather in September

In September, Sapporo sees average daytime highs of 20°C and overnight lows near 13°C, with 155 mm of rain across 14.7 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 18°C by the end. The sky is clear or mostly clear about 22% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Sapporo's 6th-clearest and 9th-windiest month. For the whole year in context, see Sapporo's year-round climate.

Daytime high
20°
3rd warmest
Overnight low
13°
10th coldest
Rainfall
155 mm
14.7 wet days
Daylight
12 h 18 min
5:20 AM – 5:38 PM
Cloud cover
66%
6th clearest
Wind
8 km/h
9th windiest
Solar energy
3.74 kWh/m²
Travel score
5.5
out of 10

Sapporo is city on Hokkaido, Japan.

Air quality
Moderate
PM2.5 14 µg/m³ · 2010
Density
1,760/km²
people per km²
Founded
1922

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 22°C in the first days to 18°C by the end.

A typical September day in Sapporo reaches about 20°C in the afternoon and slips back to 13°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 24°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12316
22316
32216
42216
52215
62215
72215
82215
92215
102114
112114
122114
132114
142114
152013
162013
172013
182013
192012
201912
211912
221912
231911
241911
251811
261811
271810
281810
291810
301710

How September really feels in Sapporo

Once humidity and wind are folded in, September 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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Sapporo weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-3° / -10°5110.316.39.20.0
Feb-2° / -9°469.814.110.20.0
Mar / -6°6412.112.811.60.0
Apr / 7311.95.413.11.8
May15° / 9312.60.414.44.3
Jun19° / 12°8911.9015.15.7
Jul23° / 16°13813.9014.96.0
Aug24° / 18°19114.2013.86.1
Sep20° / 13°15514.7012.35.5
Oct14° / 9913.60.710.83.8
Nov / -0°8814.49.29.50.7
Dec-1° / -6°7312.717.78.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 61%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13466
23466
33565
43565
53565
63565
73565
83664
93664
103664
113763
123862
133961
143961
154060
164060
174159
184258
194258
204258
214258
224258
234258
244357
254357
264357
274357
284456
294456
304456

Chance of precipitation in September

Any precipitation

Sapporo gets around 155 mm of rain over 14.7 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 49% and peaks near 50% on the wettest days.

0%20%40%60%151015202530
Rain chance (%)
147
247
347
448
548
648
749
849
949
1049
1150
1250
1350
1449
1549
1649
1749
1849
1949
2049
2149
2249
2349
2449
2549
2649
2749
2849
2949
3048

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 44% of days. Sticky, muggy-or-worse air turns up on roughly 9% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1122936212
2133035202
3143034192
4163133182
5173232172
6193331162
7203330152
8233428142
9253427132
10273525121
11293523111
12323522101
1335352091
1438351881
1541341781
1644341571
1747331361
1850331250
1953321050
205731840
215930740
226229630
236428530
246727420
256926320
267324210
277423210
287622110
297920100
308118100

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:03 AM to 5:36 AM, and sunset from 6:05 PM to 5:11 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:036:05
213.05:046:03
312.95:066:02
412.95:076:00
512.85:085:58
612.85:095:56
712.75:105:54
812.75:115:53
912.65:125:51
1012.65:135:49
1112.55:155:47
1212.55:165:45
1312.45:175:43
1412.45:185:41
1512.35:195:39
1612.35:205:38
1712.25:215:36
1812.25:235:34
1912.15:245:32
2012.15:255:30
2112.05:265:28
2212.05:275:26
2311.95:285:24
2411.95:295:23
2511.85:315:21
2611.85:325:19
2711.75:335:17
2811.75:345:15
2911.65:355:13
3011.65:365:11

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.74 kWh/m².

For context, solar energy here swings from a low near 1.64 kWh/m² to a high of 5.5 kWh/m² in May across the year — September's 3.74 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.1Bright
24.0Bright
34.0Bright
44.0Bright
54.0Moderate
64.0Moderate
73.9Moderate
83.9Moderate
93.9Moderate
103.9Moderate
113.8Moderate
123.8Moderate
133.8Moderate
143.8Moderate
153.8Moderate
163.7Moderate
173.7Moderate
183.7Moderate
193.7Moderate
203.6Moderate
213.6Moderate
223.6Moderate
233.6Moderate
243.5Moderate
253.5Moderate
263.5Moderate
273.5Moderate
283.4Moderate
293.4Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Sapporo

In seasonPeak

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

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

Sapporo's rainy season runs May–November, 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 September a good time to visit Sapporo?

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

5.5
Sightseeing
4th-best month of the year
3.0
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Sapporo for sightseeing.

What to pack for Sapporo in September

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

In September, Sapporo sees daytime highs around 20°C and nights near 13°C. Pack rain gear. About 15 days see rain.

rain gear

Sea temperature near Sapporo in September

The nearest coast averages about 21°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 34 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 in Sapporo in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sapporo 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

Air quality in Sapporo in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Sapporo is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 9 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Sapporo's WHO annual average of 14 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1222 µg/m³Dec 159 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb16Moderate
Mar21Moderate
Apr22Moderate
May20Moderate
Jun14Moderate
Jul13Moderate
Aug11Good
Sep10Good
Oct12Good
Nov10Good
Dec9Good
Location & terrain

Where is Sapporo?

Sapporo sits at 43.1°N, 141.3°E, 26 m above sea level, in Japan. The nearest listed city is Ebetsu, 17 km away.

Topography around Sapporo

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

Within 3 km, the terrain around Sapporo has only modest variations in elevation — a maximum elevation change of 37 m around an average of 20 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,095 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,863 m.

The land around Sapporo is covered by artificial surfaces (90%) within 3 km, trees (44%) and artificial surfaces (36%) within 16 km, and trees (57%) and water (27%) within 80 km.

3 km
37 m
16 km
1,095 m
80 km
1,863 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ebetsu 17 km · Ishikari 19 km · Kitahiroshima 20 km · Tōbetsu 22 km · Eniwa 27 km · Otaru 31 km · Iwamizawa 36 km · Chitose 37 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 Sapporo (43.0667°, 141.35°, elevation 26 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).