“Siren,” 7 p.m. on Freeform
Mating season turns out to be far less successful than both humans and merfolk had hoped, leading to new conversations over the possibility of the mermaids trying to procreate on land in a new episode called “The Last Mermaid.” For the good of the colony, Ryn (Eline Powell) brings a new mate ashore, but that action only serves to raise some painful emotional questions for Ben and Maddie (Alex Roe, Fola Evans-Akingbola).
“Unspouse My House,” 9 p.m. on HGTV
A single father of two in Huntington Beach, Calif., wants to make a fresh start, but his tired and outdated home is depressing, not least because it constantly reminds him of the ex-wife who walked out on him and his children. Luckily, Orlando Soria has a plan to breathe new life and freshness into this living space, starting with throwing out the ugly tile and gaudy, over-the-top furniture.
“Forecast: Shark Attack,” 9 p.m. on National Geographic
Shark expert Dr. Greg Skomal and meteorologist Joe Merchant travel together to the Bahamas to test a theory that weather has a direct correlation to shark attacks, in this new special. The duo is convinced that wind may drive sharks closer to the shore for their hunting, which in turn brings them into closer contact with swimmers in those waters.