July holidays...
July 13, Wednesday, Asanha Bucha Day
July 14, Thursday, Khao Phansa Day (Buddhist Lent)
July 15, Friday, Extra public holiday
July 28, Thursday, King Vajiralongkorn's Birthday
July 29, Friday, Additional special holiday
All above dates includes immigration, land transport and other government offices are closed.
13, 28, 29 only are bank holidays. Main branches closed, satellite offices such as in malls normally open. 13, 14 - Buddhist holidays so dry days (Not about possible rain, but no sales of alcohol).
If your Admitted or permitted to stay is on one of the closed days and you can not manage to go before that day, you can go the first working day after. You may get an extra stamp with overstay but no fines due to closed for holidays.
Take care
TLDR : Answer Summary
In July, Thailand has several public holidays that affect immigration and government services. Key dates include Asanha Bucha Day on July 13, Khao Phansa Day on July 14, King Vajiralongkorn's Birthday on July 28, and additional holidays on July 15 and 29. During these days, immigration and transport offices are closed. Notably, July 13, 28, and 29 are also bank holidays where main branches shut down, though satellite offices may remain open. On Buddhist holidays (July 13 and 14), the sale of alcohol is prohibited. If your stay is affected by these closures, you can visit an office on the next working day without fines for overstays.