NEW YORK— It’s a frightful world on TV these days.

A rash of scripted summer thrillers cautions viewers to batten down the hatches. Watch out who you let nibble on your neck! Hold your loved ones tight before they vanish into thin air! And with all the deadly viruses at large, you better bathe in Purell!

A certain brand of TV drama has always kept its audience on high alert, at least as far back as “The Twilight Zone.” But these days, with agencies hacking your email, new diseases cropping up, ice caps melting and drones overhead, viewers are sitting ducks for the titillation of dramatized threats to offer welcome distraction from the real thing.

The message is clear: Danger lurks everywhere. On your airline flight, you might get something even worse than the food, resulting in a plane that lands at JFK full of passengers-turned-corpses.

That’s the big start of “The Strain,” premiering July 13. And things quickly worsen. Side effects for each victim on this FX series include rapid hair loss and a blood-sucking proboscis.

This apocalypse has been loosed by evil forces. The only hope for humanity’s salvation is Dr. Ephraim Goodweather (played by series star Corey Stoll). He vows to save the day.

Same with the pandemic on TNT’s new “The Last Ship” (airing Sundays). By chance, an Arctic-stationed Navy destroyer has evaded this mass outbreak, leaving the crew with the duty of saving what’s left of humanity. Good thing they just happen to have onboard a renowned paleomicrobiologist, Dr. Rachel Scott (played by Rhona Mitra). She’s humanity’s only hope for salvation. She vows to save the day.

This virus of unknown origin has already killed 80 percent of the world’s population.

By contrast, a relatively meager 2 percent have disappeared on “The Leftovers,” abracadabra, with no warning. But the 98 percent left behind are reeling from the mass exodus.

This HBO series (premiering Sunday) focuses on what’s left of tiny Mapleton, New York, as citizens scratch their heads and feud about the root cause: rapture, or random catastrophe?

Meanwhile, birth control — in outer space — poses a dilemma on the CBS drama “Extant” (premiering July 9).

Halle Berry plays an astronaut who returns home from a yearlong solo mission only to discover that, on her flight, she was somehow impregnated. Pretty awkward, since she has a husband who was waiting faithfully back at home — and who, like her, had long believed she was unable to conceive.

Could she be the victim of an extraterrestrial roofie? But who’s the dad? Something sinister seems to be afoot, with a NASA official part of the mischief. And to make matters worse, the adorable robot child she and hubby are raising as their flesh-and-blood son just might be a psychopath, not to mention the harbinger of a robot uprising.

Is there any refuge from robot bullies, killer germs and cosmic abductions?

Well, you might look to Chester’s Mill, Maine, a once-serene village that was cut off from the outside world, with no notice or explanation, by a Pyrex-on-steroids prison.

This, of course, is the plight on “Under the Dome,” the CBS hit returning for its second season tonight. The citizens of Chester’s Mill are protected from invaders all right, but they manage to create plenty of grief for themselves, isolated claustrophobically within.

So pick your poison:

Cajun Country is plagued by the sexy but menacing vampires of “True Blood” (airing its final season on HBO on Sundays).

In post-apocalyptic Boston, civilians battle an intergalactic alien invasion on TNT’s “Falling Skies” (in its fourth season on Sundays).

And if they know what’s good for them, New Yorkers are bracing for the signature assault of the summer. A sequel to last year’s goofy Syfy horror film, “Sharknado,” is set for August, when a torrent of man-eating sharks will terrorize the Big Apple.

Not that well-heeled residents will be in harm’s way. They’ll all be safe and comfortable, out in the Hamptons.