Saijō weather in September

In September, Saijō sees average daytime highs of 26°C and overnight lows near 21°C, with 216 mm of rain across 14.1 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 24°C by the end. The sky is clear or mostly clear about 30% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Saijō's 9th-clearest and 8th-windiest month. For the whole year in context, see Saijō's year-round climate.

Daytime high
26°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
216 mm
14.1 wet days
Daylight
12 h 12 min
5:55 AM – 6:08 PM
Cloud cover
62%
9th clearest
Wind
9 km/h
8th windiest
Solar energy
4.27 kWh/m²
Travel score
6.0
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 28°C in the first days to 24°C by the end.

A typical September day in Saijō reaches about 26°C in the afternoon and slips back to 21°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 28°C. Set against its neighbours, September runs about 3°C cooler than August and about 5°C warmer than October.

15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12823
22823
32823
42823
52823
62723
72723
82722
92722
102722
112722
122722
132622
142621
152621
162621
172621
182621
192521
202520
212520
222520
232520
242420
252419
262419
272419
282419
292419
302319

How September really feels in Saijō

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.

Saijō 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 / 7813.53.4101.1
Feb / 8412.13.210.71.5
Mar12° / 12213.4111.72.9
Apr17° / 10°13411.60.112.85.1
May21° / 15°15811.2013.76.3
Jun24° / 19°24915.1014.25.7
Jul28° / 23°22815.60145.1
Aug29° / 24°15113.8013.35.0
Sep26° / 21°21614.1012.26.0
Oct21° / 16°16611011.16.4
Nov15° / 10°909.9010.24.8
Dec10° / 9012.81.69.82.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% 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 53%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24654
34555
44555
54555
64555
74555
84555
94654
104654
114753
124753
134753
144753
154753
164654
174654
184753
194753
204654
214753
224654
234753
244753
254753
264753
274852
284951
294951
305050

Chance of precipitation in September

Any precipitation

Saijō gets around 216 mm of rain over 14.1 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 47% and peaks near 51% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
150
250
350
451
551
651
751
851
951
1050
1150
1249
1349
1448
1547
1647
1746
1846
1945
2045
2144
2244
2343
2443
2542
2642
2742
2842
2942
3042

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 31% of days. Sticky, muggy-or-worse air turns up on roughly 61% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
101928602
2011029591
3021030571
4021131551
5021232531
6131333501
7131433481
8141534461
9151634441
10151735411
11261835391
12271934371
13282034351
14392133321
153112233301
164122432281
174132531261
185142630240
196152729220
206172828200
217182927190
228193026170
238203126150
249213225140
2510213224120
2610223323110
2711233323100
281224332290
291324342180
301425342070

Wind in September

Winds average 9 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
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 42 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 60 minutes over September. Sunrise moves from 5:45 AM to 6:06 AM, and sunset from 6:29 PM to 5:48 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:456:29
212.75:456:28
312.75:466:26
412.65:476:25
512.65:486:24
612.65:486:22
712.55:496:21
812.55:506:19
912.55:506:18
1012.45:516:17
1112.45:526:15
1212.45:536:14
1312.35:536:12
1412.35:546:11
1512.25:556:09
1612.25:556:08
1712.25:566:06
1812.15:576:05
1912.15:576:03
2012.15:586:02
2112.05:596:01
2212.06:005:59
2312.06:005:58
2411.96:015:56
2511.96:025:55
2611.86:035:53
2711.86:035:52
2811.86:045:50
2911.76:055:49
3011.76:065:48

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.27 kWh/m².

For context, solar energy here swings from a low near 2.35 kWh/m² to a high of 5.61 kWh/m² in May across the year — September's 4.27 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
144.4Bright
154.3Bright
164.3Bright
174.3Bright
184.2Bright
194.2Bright
204.2Bright
214.2Bright
224.1Bright
234.1Bright
244.1Bright
254.0Bright
264.0Bright
274.0Moderate
284.0Moderate
293.9Moderate
303.9Moderate
Planning a trip in September

Hazard calendar for Saijō

In seasonPeak

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

Saijō 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

Is September a good time to visit Saijō?

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

6.0
Sightseeing
3rd-best month of the year
5.7
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Saijō for sightseeing.

What to pack for Saijō in September

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

In September, Saijō sees daytime highs around 26°C and nights near 21°C. Pack rain gear. Worth having: light clothes. About 14 days see rain.

rain gearlight clothes

Sea temperature near Saijō in September

The nearest coast averages about 27°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 24 km away) is warmest in August at about 28°C and coldest in February near 13°C.

It's comfortable for a long swim from Jun 3 to Nov 14 — about 5.4 months when the water holds above 20°C.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb13Bracing
Mar13Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul25Warm
Aug28Warm
Sep27Warm
Oct24Refreshing
Nov20Cool
Dec17Cool

UV index in Saijō in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Saijō peaks around July 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highModerateJul 12UV 10Dec 22UV 3
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep10Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Saijō 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 Saijō is worst in April — around 22 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (October, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1321 µg/m³Oct 1311 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb16Moderate
Mar20Moderate
Apr22Moderate
May19Moderate
Jun16Moderate
Jul13Moderate
Aug12Moderate
Sep11Good
Oct11Good
Nov12Good
Dec11Good
Location & terrain

Where is Saijō?

Saijō sits at 33.9°N, 133.2°E, 8 m above sea level, in Japan. The nearest listed city is Niihama, 12 km away.

Topography around Saijō

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

Within 3 km, the terrain around Saijō has significant variations in elevation — a maximum elevation change of 275 m around an average of 16 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,886 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,900 m.

The land around Saijō is covered by artificial surfaces (46%) and cropland (25%) within 3 km, trees (50%) and water (31%) within 16 km, and trees (58%) and water (34%) within 80 km.

3 km
275 m
16 km
1,886 m
80 km
1,900 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Niihama 12 km · Imabari 24 km · Tōon 30 km · Shikokuchūō 34 km · Shinagawa 35 km · Hōjō 38 km · Kawanoechō 38 km · Matsuyama 40 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 Saijō (33.9167°, 133.1833°, elevation 8 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).