Best month to buy cheapest summer clothes?

Planning to visit Osaka for a week either on September / October / November. Would like to ask which week of which month would have the best summer clothes sales. Thank you in advance.

I wouldn't think that summer sales would be around October/November. Most shops have their Fall/Winter stock displayed. September would be the latest I think, even late August, even if the temperatures are still high. You should go to Uniglo, they are never expensive even at full price, are fashionable, and if they are discounting, it is usually a good sale. You may have issues with some sizes, but they are now a big international company so I would recommend them.

I agree with the poster above. Stores are already selling autumn fashions by August even though it is still midsummer. It could be difficult to find summer clothes in October or later.

Thank you both for your reply.
I already booked my flight on 26th August for a week's trip.