Total fire bans have been put in place for five districts in South Australia, with hot weather and northerly winds forecast for Wednesday.

Operation Nomad, which monitors known firebugs and checks suspicious activity, will target bushfire prone areas throughout the state, police say.

The CFS says the fire bans have been declared for the Northwest Pastoral, West Coast, Eastern Eyre Peninsula, Mount Lofty Ranges and Lower South East districts.

The Mount Lofty Botanic Gardens is closed to the public on Wednesday.

Adelaide is expected to reach 36C.