The local dishes that can be eaten in Hokkaido in September are “Chanchan-yaki”, “Ishikari-nabe”, and “Jingisukan”.
In the season of salmon, “Chanchan-yaki”, which is made by grilling salmon and vegetables and seasoning with miso, and “Ishikari-nabe”, which is made by boiling salmon with seasonal vegetables, are exactly the taste of autumn in Hokkaido. In addition, since “Jingisukan” can be eaten all year round, all three types of Hokkaido’s local cuisine listed in the “100 selections of local cuisine” selected by the Ministry of Agriculture, Forestry and Fisheries can be eaten in September.
https://www.maff.go.jp/j/nousin/kouryu/kyodo_ryouri/attach/pdf/190131-1.pdf
In addition, I have previously reported that “Uni-ikura-don (sea urchin salmon roe bowl)” and “Soup curry” are listed as local dishes in Hokkaido in the “Local dishes loved by the nation” announced by the Ministry of Agriculture, Forestry and Fisheries.
https://www.maff.go.jp/j/nousin/kouryu/kyodo_ryouri/attach/pdf/190131-6.pdf
The season for raw salmon roe is from September to November. Sea urchins are not caught in Hokkaido from September to November, so it is the best season for those who like salmon roe of “Uni-ikura-don”, but it is a disappointing season for those who like sea urchins. Of course, “Soup curry” can be eaten all year round.