Sendai weather in September

In September, Sendai sees average daytime highs of 24°C and overnight lows near 17°C, with 167 mm of rain across 14.3 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 21°C by the end. The sky is clear or mostly clear about 18% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Sendai's 9th-clearest and 9th-windiest month. For the whole year in context, see Sendai's year-round climate.

Daytime high
24°
3rd warmest
Overnight low
17°
10th coldest
Rainfall
167 mm
14.3 wet days
Daylight
12 h 12 min
5:24 AM – 5:38 PM
Cloud cover
72%
9th clearest
Wind
8 km/h
9th windiest
Solar energy
3.53 kWh/m²
Travel score
5.8
out of 10

Sendai is city in Miyagi Prefecture, Japan.

Air quality
Good
PM2.5 7 µg/m³ · 2010
Density
1,395/km²
people per km²
Founded
1889

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 26°C in the first days to 21°C by the end.

A typical September day in Sendai reaches about 24°C in the afternoon and slips back to 17°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 28°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12620
22620
32620
42519
52519
62519
72519
82519
92519
102518
112418
122418
132418
142418
152417
162417
172317
182317
192316
202316
212316
222216
232215
242215
252215
262215
272215
282114
292114
302114

How September really feels in Sendai

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.

Sendai weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°6310.99.99.60.0
Feb / -3°499.27.710.50.0
Mar / -0°8711.65.411.71.4
Apr14° / 9411.21.1134.0
May19° / 11°10311.40145.8
Jun22° / 16°12913.4014.65.8
Jul26° / 20°18717.4014.45.3
Aug27° / 21°16916.2013.55.4
Sep24° / 17°16714.3012.35.8
Oct18° / 11°141110115.6
Nov12° / 639.30.99.93.3
Dec / -0°581169.40.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 13% of September, with mostly cloudy or overcast conditions the remaining 69%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13070
23070
33169
43169
53070
63070
73169
83169
93169
103169
113169
123070
133169
143070
153169
163070
173169
183070
193070
203169
213169
223169
233268
243268
253367
263367
273466
283466
293466
303466

Chance of precipitation in September

Any precipitation

Sendai gets around 167 mm of rain over 14.3 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 54% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
153
253
354
454
554
654
753
853
953
1052
1152
1252
1351
1451
1550
1649
1749
1848
1947
2046
2145
2244
2344
2443
2543
2643
2742
2842
2942
3042

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 28% of days. Sticky, muggy-or-worse air turns up on roughly 35% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1082438282
2082538272
3192637252
41102737242
51112737232
61122836212
72132836202
82142835191
93162934181
104172933171
115182932151
126193030141
137203029131
149223027120
1510233025110
1612243124100
171425312290
181626302080
191827301870
202028301660
212229301550
222430291340
232631281230
242832281030
25293327920
26313426820
27333524710
28353523610
29363622510
30383620500

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 72 minutes over September. Sunrise moves from 5:10 AM to 5:36 AM, and sunset from 6:02 PM to 5:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:106:02
212.85:116:01
312.85:125:59
412.75:135:58
512.75:145:56
612.75:155:54
712.65:165:53
812.65:165:51
912.55:175:50
1012.55:185:48
1112.55:195:46
1212.45:205:45
1312.45:215:43
1412.35:225:41
1512.35:235:40
1612.25:245:38
1712.25:245:37
1812.25:255:35
1912.15:265:33
2012.15:275:32
2112.05:285:30
2212.05:295:28
2311.95:305:27
2411.95:315:25
2511.95:325:23
2611.85:335:22
2711.85:345:20
2811.75:345:19
2911.75:355:17
3011.75:365:15

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.53 kWh/m².

For context, solar energy here swings from a low near 2.06 kWh/m² to a high of 5.34 kWh/m² in May across the year — September's 3.53 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.8Moderate
43.7Moderate
53.7Moderate
63.7Moderate
73.7Moderate
83.6Moderate
93.6Moderate
103.6Moderate
113.6Moderate
123.5Moderate
133.5Moderate
143.5Moderate
153.5Moderate
163.5Moderate
173.5Moderate
183.4Moderate
193.4Moderate
203.4Moderate
213.4Moderate
223.4Moderate
233.4Moderate
243.3Moderate
253.3Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.3Moderate
303.2Moderate
Planning a trip in September

Hazard calendar for Sendai

In seasonPeak

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

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

Sendai's rainy season runs March–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 Sendai?

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

5.8
Sightseeing
1st-best month of the year
4.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Sendai for sightseeing.

What to pack for Sendai in September

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

In September, Sendai sees daytime highs around 24°C and nights near 17°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Sendai in September

The nearest coast averages about 23°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 28 km away) is warmest in August at about 24°C and coldest in March near 9°C.

It's comfortable for a long swim from Jul 7 to Oct 10 — about 3.2 months when the water holds above 20°C.

5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan11Bracing
Feb9Bracing
Mar9Bracing
Apr10Bracing
May14Bracing
Jun18Cool
Jul21Refreshing
Aug24Refreshing
Sep23Refreshing
Oct19Cool
Nov17Cool
Dec14Bracing

UV index in Sendai in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sendai peaks around August 16 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateAug 16UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun8Very high
Jul8Very high
Aug9Very high
Sep8Very high
Oct5High
Nov3Moderate
Dec2Low
Location & terrain

Where is Sendai?

Sendai sits at 38.3°N, 140.9°E, 53 m above sea level, in Japan. The nearest listed city is Natori-shi, 11 km away.

Topography around Sendai

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

Within 3 km, the terrain around Sendai has only modest variations in elevation — a maximum elevation change of 173 m around an average of 67 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 513 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,978 m.

The land around Sendai is covered by artificial surfaces (74%) and trees (24%) within 3 km, trees (44%) and artificial surfaces (29%) within 16 km, and trees (57%) and water (26%) within 80 km.

3 km
173 m
16 km
513 m
80 km
1,978 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Natori-shi 11 km · Rifu 12 km · Tagajō-shi 12 km · Tomiya 14 km · Shiogama 16 km · Shōbudahama 17 km · Iwanuma 18 km · Yoshioka 19 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 Sendai (38.2667°, 140.8667°, elevation 53 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).