Osaka in September: weather, what to wear and what's on

Osaka weather in September

Averages for 1991–2020 at the JMA's Osaka station (23 m above sea level).

High

29.5°C (85°F)

Low

21.9°C (71°F)

Precipitation

152.8 mm

Wet days

9.5 days

Sunshine

162 hours

Highs fall 4.2°C from August and drop another 5.8°C into October.

That is 8.2°C above Osaka's yearly average high of 21.3°C.

Of our 14 places with temperature records, Osaka is the 2nd warmest in September: 1.1°C cooler than Naha and 0.3°C warmer than Kyoto.

September is Osaka's 3rd wettest month (152.8 mm).

Of our 15 places, Osaka has the 2nd lowest precipitation in September: 6.2 mm less than Nara and 10.6 mm more than Sapporo.

Rain of 1 mm or more falls on 9.5 days, and 10 mm or more on 4.6 days.

Rain of 30 mm or more in one day falls on 1.5 days, and 50 mm or more on 0.6 days.

14.4 days reach 30°C or more, and 0.8 reach 35°C or more.

On 4.1 nights the low stays at 25°C or above.

The sun is out for 40% or more of the possible hours on 16.6 days, and 3.3 days have under 0.1 hours of sunshine.

By the JMA's cloud records, 1.3 days are clear and 12.9 are overcast.

On 15 September 2027 the sun rises at 5:40 and sets at 18:06 in Osaka, giving 12 hours 26 minutes of daylight (NAOJ).

Average temperature

25.2°C (77°F)

Humidity

67%

Days of 25°C or more

26.9 days

Early, mid and late September

By the last ten days of September the average high in Osaka is 4.1°C lower than in the first ten.

By ten-day totals, 21–30 September is the wettest (55.1 mm) and 1–10 September the driest (48.7 mm).

What to wear in Osaka in September

Warm: highs around 29.5°C

• Short sleeves or thin long sleeves, with a light layer for air-conditioning and evenings.
• Heat: 14.4 days reach 30°C or more. A hat, water and sunscreen.
• A folding umbrella: rain falls on 9.5 days.

Pack

• Folding umbrella
• Hat, sunscreen and a water bottle
• A light layer for air-conditioning

• Our clothing rules

Rainy season and typhoons

In an average September, 1.1 typhoons come within 300 km of the Kinki region; across Japan, 3.3 come within 300 km and 1.0 make landfall (JMA, 1991–2020).

September records in Osaka

The extremes the JMA has measured in September at its Osaka station.

Hottest September day

36.5°C (98°F) on 1 September 2025 (records since 1883)

Coldest September night

10.4°C (51°F) on 28 September 1883 (records since 1883)

Wettest September day

174.0 mm on 3 September 1989 (records since 1883)

Holidays and crowds in September

National holidays in September 2027:

• Mon 20 September — Respect for the Aged Day
• Thu 23 September — Autumnal Equinox Day

• Sat 18 September to Mon 20 September: 3 days off in a row

In September 2025, hotels and inns across Osaka Prefecture were 83.4% full on average (2nd busiest of 12 months). Foreign guests spent 1.50 million nights there that month (Japan Tourism Agency). That compares with 80.7% in August and 84.9% in October.

• Japan in September: visitor numbers and busy travel days
• Holidays in September
• Silver Week

What's on in Osaka in September

Osaka before and after September

• Osaka in August
• Osaka in October
• All 12 months in Osaka

Other places in September

• All 15 places in September

Related items

• Osaka by month
• Japan in September
• Osaka in August
• Osaka in October