Fun in the sun is how most people picture their summer, but New Zealanders are being urged to see sense when it comes to water.

December has one of the worst drowning rates of the year, with 12 deaths reported already -three of these were incidents at North Island beaches yesterday alone.

Water Safety New Zealand chief executive Daniel Gerrard said the numbers so far this month were horrendous.

"We had really low drowning rates over lockdowns and now it seems like we're trying to make up for that, unfortunately," he said.

Gerrard acknowledged that New Zealanders lived in an incredible water environment, but urged people to think before they swim.

"We live in the most amazing environment. We've got water all around us. We've got lakes and beautiful rivers, we've got oceans that everyone is just enticed towards," he said.

Water Safety New Zealand (WSNZ) Chief Executive Officer Daniel Gerrard.

Water Safety New Zealand chief executive Daniel Gerrard. Photo: Supplied/Water Safety New Zealand

"We've just got to enjoy them properly, have a good time and make sure that everyone comes home."

Gerrard urged people to follow the old rule, 'if in doubt, stay out'.

"That could be you heading out in a boat to go fishing with your mates and actually, the conditions are a bit dodgy, [and you] think maybe you shouldn't go, right through to 'oh, the surf looks OK but it's actually probably bigger than I can handle, maybe I'll stay out today'," he said.

He said everyone should know their limits in water and be mindful of conditions, especially at the beach.

"If you are at the beach, you should swim between the flags and if anyone is unsure of the conditions, you should chat to a lifeguard before going into the water."

Gerrard said the country had fantastic lifeguards, some of whom gave their time to keep New Zealanders safe in the water over the summer.