Osaka Weather in September

Season: Autumn
In short:
1. As autumn of Osaka begins in September, the temperature sees a small decrease this month.
2. The precipitation of the city this month is high, mainly caused by typhoon activities.
3. Not too many visitors travel to Osaka this month, thus leading to not-so-high prices of hotel rooms and air flights.

Famous Tsutenkaku in Bustling Shinsekai

Slightly Decreasing Temperature

Hozenji Temple, Osaka

Osaka in September experiences a transition from summer to autumn, and its temperature has a slight decrease this month.

In early-to-mid September, the weather of Osaka is still hot, with the daily high between 30 and 34 degrees Celsius (86 and 93 degrees Fahrenheit) on most days. As for the daily low in this period, it mostly ranges from 25 to 28° (77 to 82°F), a much cooler level compared with that during the daytime. Given this, you are recommended to take full use of the early morning and evening to travel around.

In late September, people can practically feel the start of cool autumn: the highest temperature in a day decreases to a range from 25 to 28°C (77 to 82°F), so the daytime gradually becomes pleasant for outdoor sightseeing. It’s further noteworthy that the daily low can be 19 or 20°C (66 or 68°F), resulting in a large temperature variation for 8°C (14°F) on some days. So, you’re suggested to bring additional clothes to reduce the discomfort caused by the temperature decrease in a day.

High Precipitation Brought by Typhoons

In September, Osaka gets high rainfall, which sums up to about 153 mm and is scattered over about 9 days on average. Typhoon activities are frequent this month, and the city may be affected by the periphery of typhoons, which means rainstorms can happen and the city can experience rainy days in a row. To minimize the impact of typhoons on your tour, you’re advised to keep an eye on the latest weather conditions and make according adjustments to your itinerary if necessary.

Even outside the typhoon periods, complicated precipitation situations can occur this month: sometimes, patchy rain falls all day long; and sometimes, a downpour with lightning happens in the afternoon, probably leading to suspension of all the amusement facilities in Universal Studios Japan. In view of this, high precipitation in September becomes an unfavorable factor for people to enjoy an Osaka tour, and this month thus becomes a relatively slack period of the city in a year.

Sometimes Quite Muggy Weather

Shitennoji Temple on Clear Day

The average humidity of Osaka in September can be around 70%, which is quite high throughout the year. This factor on hot days causes the actual sensible temperature to be higher than the real one, and people will feel even hotter.

Daytime & UV Index

Daytime of Osaka in September shortens day by day, from about 13 to 12 hours. Due to relatively high precipitation, the city doesn’t get too long daily sunshine duration averagely this month, which lasts for around 5 hours. Another unneglectable factor is the UV index, whose maximum value can be high at 8, and people had better take enough measures to protect their skin from strong UV radiation, especially around sunny noon in early-to-mid this month.

Clothes Advice in Osaka in September

In early-to-mid September: Thin clothes made of quick-dry materials are suitable. For example, you can pick a vest or a T-shirt as your top, and wear shorts as bottoms. Ladies can also bring skirts and dresses. Here is another option: to ensure both comfort and sun protection, you can consider long-sleeved and loose outfits made of linen.

In late September: To cope with occasional large temperature differences between day and night, in addition to the above clothes, a thin jacket is needed.

Shoes: Sandals, breathable sneakers, and flats are recommended to bring. It’s necessary to wear ones with anti-slippery property, in case you visit waterside spots in mountain areas.

Others: An all-weather umbrella, a portable fan, and sun-protective products.

Top Things to Do in Osaka in September

1. Visit the Landmark Osaka Castle

As an undoubtedly must-go attractions in the city, the Osaka Castle welcomes tourists with its magnificent keep, complete moat, and attractive natural views. In the early morning and late afternoon on sunny days, the good visibility and less hot weather make it suitable to enjoy all of these.

Osaka Castle Keep in September

2. Admire the Ancient Complex in Sumiyoshi Taisha Shrine

This shrine is probably the only place where you can find so many ancient buildings like stone torii gates and great halls in Osaka. This month, pine trees here are covered with green branches, setting well against the iconic vermilion arch bridge under the clear blue sky.

Sumiyoshi Taisha Shrine with Arch Bridge

3. View Maritime Animals in Osaka Aquarium Kaiyukan

Indoor places are suitable to visit on either hot or rainy days. In the aquarium, active jellyfish, otters, and penguins are all unmissable to view, and you can further go through the “water tunnel” to see ray fish swimming slowly.

View Tropical Fish in Osaka Aquarium Kaiyukan

People Enter Aqua Gate

4. Feast both Eyes and Stomach in Dotonbori

Dotonbori is famous for fabulous night views with neon lights and also authentic food like okonomiyaki and Takoyaki. This place is the first option for people who want to have a night tour in Osaka, and at night this month, the weather is just ideal and favorable for visiting.

Impressive Street View by Dotonbori River

What’s Else Special about Osaka in September?

1. Kishiwada Danjiri Festival

Osaka’s Kishiwada Danjiri Festival 2026 falls on September 13 and 14, when people hold the most exciting activity in a year to pray for a good harvest and stability. People stand on the elaborately designed floats, which are pulled on the street at top speed, even when passing by corners. Anyone who closely watches the grand parade will be amazed by the carnival atmosphere it’s in.

2. Suito Kurawanka Fireworks

The Suito Kurawanka Fireworks are usually displayed in mid-to-late September, to welcome babies newly born in the past year. What’s even more memorable is that the number of fireworks is equal to that of the newborn babies. Many people choose to rent and wear the traditional Japanese costume yukata, and take photos with the exploding fireworks in the dark sky.