Date weather in September

In September, Date sees average daytime highs of 21°C and overnight lows near 15°C, with 134 mm of rain across 11.7 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 23°C in the first days to 19°C by the end. The sky is clear or mostly clear about 28% 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 Date's 6th-clearest and 9th-windiest month. For the whole year in context, see Date's year-round climate.

Daytime high
21°
3rd warmest
Overnight low
15°
10th coldest
Rainfall
134 mm
11.7 wet days
Daylight
12 h 18 min
5:22 AM – 5:39 PM
Cloud cover
64%
6th clearest
Wind
10 km/h
9th windiest
Solar energy
3.72 kWh/m²
Travel score
6.1
out of 10

Date is city in Hokkaidō, Japan.

Density
79/km²
people per km²
Founded
2006

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 23°C in the first days to 19°C by the end.

A typical September day in Date reaches about 21°C in the afternoon and slips back to 15°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 24°C. Set against its neighbours, September runs about 3°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12318
22317
32317
42317
52317
62317
72217
82216
92216
102216
112216
122216
132215
142115
152115
162115
172115
182114
192114
202014
212014
222013
232013
242013
251913
261913
271912
281912
291912
301812

How September really feels in Date

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.

Date 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-1° / -7°447.911.79.20.0
Feb-1° / -7°406.98.910.30.0
Mar / -4°549.67.911.60.0
Apr / 7010.31.913.11.8
May14° / 8910.9014.44.2
Jun18° / 13°759015.15.8
Jul22° / 17°13112.7014.86.0
Aug24° / 19°16512013.76.4
Sep21° / 15°13411.7012.36.1
Oct15° / 8610.70.110.84.4
Nov / 74113.19.61.1
Dec / -4°6010.312.38.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 58%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43862
53763
63763
73763
83961
93961
104060
114060
124060
134159
144159
154258
164258
174357
184456
194456
204456
214555
224654
234753
244753
254753
264753
274654
284654
294753
304753

Chance of precipitation in September

Any precipitation

Date gets around 134 mm of rain over 11.7 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 39% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
140
240
340
440
540
640
740
840
940
1040
1140
1240
1339
1439
1538
1638
1738
1838
1938
2038
2138
2238
2338
2439
2539
2639
2739
2839
2939
3039

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 35% of days. Sticky, muggy-or-worse air turns up on roughly 13% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
182138267
292238257
3102338246
4112337226
5122437216
6142537205
7152636185
8172635175
9182734164
10202833154
11232932134
12252930123
13273029113
14303027103
1533312592
1635312382
1738322172
1841321962
1943321762
2046321651
2148321441
2250331241
2352331131
245532931
255732821
265832721
276231610
286430510
296628510
306927400

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

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 5:06 AM to 5:38 AM, and sunset from 6:07 PM to 5:14 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:066:07
213.05:076:05
312.95:086:03
412.95:096:01
512.85:105:59
612.85:115:58
712.75:125:56
812.75:145:54
912.65:155:52
1012.65:165:50
1112.55:175:49
1212.55:185:47
1312.45:195:45
1412.45:205:43
1512.35:215:41
1612.35:225:39
1712.25:235:37
1812.25:255:36
1912.15:265:34
2012.15:275:32
2112.05:285:30
2212.05:295:28
2311.95:305:26
2411.95:315:25
2511.85:325:23
2611.85:335:21
2711.75:355:19
2811.75:365:17
2911.65:375:15
3011.65:385:14

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.72 kWh/m².

For context, solar energy here swings from a low near 1.71 kWh/m² to a high of 5.39 kWh/m² in May across the year — September's 3.72 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.9Moderate
23.9Moderate
33.9Moderate
43.9Moderate
53.9Moderate
63.8Moderate
73.8Moderate
83.8Moderate
93.8Moderate
103.8Moderate
113.8Moderate
123.8Moderate
133.7Moderate
143.7Moderate
153.7Moderate
163.7Moderate
173.7Moderate
183.7Moderate
193.7Moderate
203.6Moderate
213.6Moderate
223.6Moderate
233.6Moderate
243.6Moderate
253.5Moderate
263.5Moderate
273.5Moderate
283.5Moderate
293.4Moderate
303.4Moderate
Planning a trip in September

Hazard calendar for Date

In seasonPeak

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

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

Date's rainy season runs May–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

Is September a good time to visit Date?

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

6.1
Sightseeing
2nd-best month of the year
3.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Date for sightseeing.

What to pack for Date in September

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

In September, Date sees daytime highs around 21°C and nights near 15°C. Worth packing: rain gear. About 12 days see rain.

rain gear

Sea temperature near Date in September

The nearest coast averages about 20°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 21°C and coldest in February near 4°C.

It's comfortable for a long swim from Aug 9 to Sep 13 — about 1.2 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan6Bracing
Feb4Bracing
Mar4Bracing
Apr6Bracing
May9Bracing
Jun14Bracing
Jul18Cool
Aug21Refreshing
Sep20Refreshing
Oct17Cool
Nov12Bracing
Dec9Bracing

UV index in Date 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 Date 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 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighVery highHighModerateLowAug 18UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5High
May8Very high
Jun7High
Jul5Moderate
Aug9Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Date 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 Date is worst in April — around 20 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (December, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1219 µg/m³Dec 158 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb14Moderate
Mar19Moderate
Apr20Moderate
May18Moderate
Jun12Moderate
Jul11Good
Aug10Good
Sep9Good
Oct11Good
Nov9Good
Dec8Good
Location & terrain

Where is Date?

Date sits at 42.5°N, 140.9°E, 6 m above sea level, in Japan. The nearest listed city is Muroran, 19 km away.

Topography around Date

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

Within 3 km, the terrain around Date has only modest variations in elevation — a maximum elevation change of 147 m around an average of 23 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 901 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,867 m.

The land around Date is covered by water (33%), artificial surfaces (23%) and cropland (21%) within 3 km, water (48%) and trees (41%) within 16 km, and trees (53%) and water (38%) within 80 km.

3 km
147 m
16 km
901 m
80 km
1,867 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Muroran 19 km · Noboribetsu 26 km · Shiraoi 41 km · Niseko 41 km · Kutchan 49 km · Yakumo 55 km · Tomakomai 63 km · Honchō 65 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 Date (42.4681°, 140.8681°, elevation 6 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).