Summer Kimonos or Yukata
As you may know, the summer heat in Japan is harsh…However, we still want to enjoy wearing kimonos even during the summer season. In the month of July and August, we wear kimonos made from thinner materials than a usual kimono which is often called “Usu-hitoe”. Like Yukata, the summer kimonos are made from the materials that are thin and see through which is the reason why you need “Nagajuban (a simple robe)” that is normally worn underneath the kimonos. The summer kimono is lighter than the one you wear during the winter time so even though the way you wear it is not much different than the winter kimono, it feels a bit different when you touch it and try to wrap it around your body. You may feel it is not worth having the summer kimonos because they are only useful in July and August, but you may find a lot more events during the summer time than the winter time that you can go to with your kimonos, as normally, there is a lot of summer festivals held in Japan in July and August (only if we are not under the COVID-19 pandemic). Also, in the summertime, you would wear Nagajuban for summer which is also thinner than the one for winter.
So what kind of kimono would you wear after August?
You would wear a type of kimono called “Hitoe” which can be worn in June and September. The typical type of Hitoe is called “Ro-Chirimen” which is similar to “Chirimen (Crêpe, also spelt crepe or crape, which is a silk, wool, or synthetic fiber fabric with a distinctively crisp, crimped appearance according to Wikipedia)” but has a bit of space in stiches so that it feels cooler than the winter kimono.
However, as you know, September in Japan still feels like in the middle of summer most of the time, so you can still wear the summer kimono in early September.

Summer Obi
Same as kimonos, there is an obi belt for summer. The summer obi has a pattern of weaving or structure of a fabric that is different from the winter obi belt. The rough texture of the summer obi has a clearance at a texture which gives your kimono a cool, summer appearance.
Some famous summer style obi belts are:
“Ro fabric” – This type of fabric is woven with a space between a few treads which creates a striped pattern.
“Sha fabric” – This is a type of silk gauze that is even lighter than “Ro fabric.”
“Ra fabric” – This fabric has spaces within geometric patterns. Obi made from Ra fabric is the lightest obi among all summer obi belts.
“Asa fabric” – This is the fabric made from hemp clothes. It is stiff so easier to make a nice otaiko shape with the obi.
“Hakata obi” – This obi is a traditional Japanese textile that has been produced in Fukuoka Prefecture. Hakata obi can be also used in the winter time but depending on the color you choose, it may not be suitable for summer.

In the picture above, I wore the summer Nagoya obi in the otaiko shape. I am so proud that I wore these (kimono and obi) by myself! One of the most difficult parts in wearing the kimono and obi above is to bring the flower patterns in the obi belt in the right position of the otaiko shape.