The lack of water in streams and rivers in the region, combined with warming water temperatures, have created vulnerable conditions for fish in those systems. However, the ban does not apply to lake fishing.
The province also announced a Level 3 drought for the South Thompson, Nicola, Similkameen, Okanagan-Kettle and Skagit regions.
Last week the province banned angling on parts of Vancouver Island and the Gulf Islands when the drought rating there was increased to Level 4.
The ban in the South Okanagan will be in place from July 15 to September 15.
Dry conditions throughout the province could lead to additional fishing bans. Biologists are monitoring conditions in about 60 key angling streams throughout the province.