The bad news just keeps coming for CNN.

May was the network's worst month for total viewers during primetime in over 20 years. CNN drew an average of just 389,000 primetime viewers from April 30 to May 27. In comparison, MSNBC drew an average of 674,000 total viewers, while Fox News boasted an average of 1,692,000 total viewers.

It was also the network's second-worst month in primetime for viewers in the key demographic since October 1991.

Things were especially bad at the 7 p.m. and 9 p.m. timeslots. Piers Morgan drew an average of 417,000 total viewers and 117,000 viewers age 25-54 — the lowest numbers the 9 p.m. slot has seen in two decades. Erin Burnett received just 89,000 viewers in the key demo at 7 p.m.

The news is the latest development in CNN's worsening ratings struggle. The network had its lowest-rated month in over a decade in April. That prompted management to issue stern warnings about improving numbers. However, the recent dismal results are not surprising, given that the network hit a 20-year primetime low during the week of May 14.