1) “Celebrity Who Wants to Be a Millionaire” season-opener, 8 p.m., ABC. The season starts with two interesting duos. First, Larry David is paired with his daughter Cazzie, a writer and actress. (They’re shown here.) Then Ben Affleck teams with Jamie Ding, who won 31 straight nights of “Jeopardy.”
2) “Pompeii: Out of Time,” 8-11 p.m., National Geographic. People are familiar with the volcanic eruption that buried a town and killed more than 1,000 people. But now Tom Hiddleston, an actor and history buff, brings a fascinating approach, both humanistic and scientific, He visits the site, talks with experts and traces three individual lives.
3) “Nation’s Dumbest,” 9 p.m., Fox. Yes, this show is wildly unfair at times. Questions vary widely in difficulty; one round give a huge advantage to people sitting at the end. Still, it’s great fun. Last week, Elle King (her own school years tattered) topped brainy Andrew Yang and Drew Pinsky; now JoJo Siwa and Steve-O flash some impressive moments.
4) “In the Heat of the Night” (1967), 10 p.m. ET, Turner Classic Movies. Two great actors — Rod Steiger and Sidney Poitier — collided brilliantly. There were Oscars for Steiger, the movie, the script and more. Also: a nomination for director Norman Jewison, whose excellent “Thomas Crown Affair” and “A Soldier’s Story” — are at 8 and midnight.
5) MORE: CBS has its new Wednesday line-up, with “Big Brother” at 8 p.m. and a “Survivor” rerun at 9:30. From 9-11 p.m., ABC has “Shifting Gears” reruns and Freeform has the season-finales of “Million Dollar Nannies.”