It only happens when the weather gets really cold, like in the lower 30s, which doesn’t happen very often down here in southeastern Louisiana.

Last year, winter was a virtual no-show, so it didn’t happen then.

But a couple years back, when the temperatures plunged into the low-to-mid 30s in January and February and parked there for a couple days, it happened big time.

What was this great event?

Redfish moved into the Yscloskey Bayou all around the drawbridge to Shell Beach and Hopedale, and they ganged out right there until the temperatures rose into the 40s.

But as soon as it warmed up, they vanished.

The fishing, which can be frenetic, happens whenever the temperatures plummet.

But word spreads fast and anglers line up on both sides of the bridge and both sides of the bayou, casting from the bank into the middle, just waiting for hungry reds to inhale their offerings.

Usually you didn’t have to wait for long. Dead shrimp on the bottom is the ticket to success, and you don’t have to tie a fancy Carolina rig or drop-shot rig to get their attention.

A wad of shrimp on a plain 3/8-ounce jighead is all you needed to get a good-sized red on the end of your line.

A couple years ago, I made five casts and caught five keeper reds. That’s how thick the fish were stacked up.

So when the temperature plunges into the low 30s this January, I called a buddy who keeps his finger on the pulse of the bayou.

“They’re here,” he said. “Come on down; I’ll save you a spot.”

The thermometer said it was 30 degrees when I left home, and by the time I got there it was a balmy 35.

Trucks were parked all along the side of the bayou, and quite a few anglers were lined up fishing despite the cold and the wind. And I watched several reel in redfish.

I also saw a Louisiana Department of Wildlife and Fisheries agent keeping an eye on things.

This section of the bayou has a thick layer of oyster shells on the bottom that attracts these fish.

There’s no guarantees February will serve up the necessary frigid temperatures to send the reds back in there — but if the forecast calls for bitter, miserable cold, bundle up and go fishing.

Just leave the boat at home.