CONCORD, N.H. -- Turn on the TV news, open a newspaper, heck, step out the front door and you can't miss it: It's been cold this winter.

Really cold.

Take your breath away cold.

Forehead aching cold.

So, naturally, ice on the state's numerous and popular-in-winter lakes is ... uneven and in some cases, dangerous.

Wait, what?

New Hampshire's Fish and Game Department is warning anglers, snowmobilers, hockey players and others who find fun in the freeze that ice levels are unpredictable and they ought to check for thickness whenever and wherever they head out.

That's despite a November and December that were almost 3 degrees colder than normal and a couple of wicked snaps where temperatures in the teens were a welcome respite.

A recent aerial survey of Lake Winnipesaukee by the New Hampshire Civil Air Patrol shows treacherous ice conditions in some parts, including an area of open water in a stretch called The Broads.

The state's largest lake at 71 square miles, it reaches a maximum depth of 212 feet.

"The cold part of this winter definitely sticks in people's minds but we can't forget that we had some very warm weather in the middle of January," said Mary Stampone, state climatologist and an assistant professor of geography at the University of New Hampshire.

When you have that warm-up/refreeze cycle, the ice weakens, Stampone said.

Throw in the size of Winnipesaukee, where the wind can push surface ice around, and a lack of sun-reflecting snow cover, and predicting the ice gets tricky.

Fish and Game Lt. James Goss said some areas that have traditionally been safe are not this year, and he advises people not to drive onto the ice.

The U.S. Army Cold Regions Research & Engineering Laboratory in Hanover offers a "rule of thumb" on ice thickness: There should be a minimum of 6 inches of hard ice before foot travel, and 8 to 10 inches for snow machine or all-terrain vehicles.

Ice is a big deal in New Hampshire.

In Meredith, more than 1,400 players on 223 hockey teams are headed to Lake Winnipesaukee for this weekend's New England Pond Hockey Classic and next weekend, anglers will converge on the tourist town for the 35th Meredith Rotary Ice Fishing Derby.

Classic founder and tournament director Scott Crowder said Friday morning that ice in Meredith Bay was 16-20 inches thick.

"We work with the states to make sure the ice is safe and we wouldn't be hosting the event if it wasn't," Crowder said about an hour after the first puck dropped.

The ice warning, he said, is just good advice when venturing out on the ice.

"At any time, ice isn't going to be 100 percent safe," Crowder said. "It freezes in different ways."

The number of teams has tripled since 2010 so canceling would be an economic blow to the region.

"It's honestly become a great weekend for the region up here," Crowder said. "Before it was really a slow period for the hotels and restaurants."

Another winter tourism draw, the ice fishing derby, has seen a 7 percent increase in ticket sales over last year.

Ice-lovers take heart: Stampone said the long-range outlook that forecasts into the middle of February calls for temperatures below normal.

That means mostly below freezing.