These claim there were raids on Hokkaido on July 14 and 15.
https://www.city.sapporo.jp.e.ain.hp..._21/index.html
https://pacificwrecks.com/date/1945/07/14.html
https://pacificwrecks.com/date/1945/07/15.html
https://pacificwrecks.com/provinces/japan_sapporo.html
On this last link
"Wartime History
On July 14, 1945 and July 15, 1945 thirty B-29 Superfortress bombers dropped
889 tons of E-46 500 lbs incendiary cluster bombs and 500 lbs T4E4 fragmentation cluster bombs into Sapporo at midday during two separate air raids. In the resulting firestorm 190 civilians were killed, 6,788 were injured, 78,000 others remained homeless, and many structures burned. A total of 17.5 percent of Sapporo was destroyed during the Pacific War."