Downhole gas separators, artificial lift systems including the downhole gas separators, hydrocarbon wells including the artificial lift systems, and methods of separating a gas from a liquid hydrocarbon within a hydrocarbon well. The downhole gas separators include an elongate outer housing that defines an enclosed volume, a fluid inlet port, and a gas outlet port. The downhole gas separators further include an elongate dip tube that extends within the enclosed volume, and the gas outlet port is configured to selectively provide fluid communication between the enclosed volume and an external region.