WINNEBAGO COUNTY, Wis. (WFRV) - Despite this extended period of bitter cold weather here in Northeast Wisconsin, local authorities continue to urge caution for anybody going out on the ice. In Lake Poygan, there's several large open water spots in the middle of the lake. Don Herman, the owner of Sunk? Dive and Ice Service, regularly monitors ice conditions on Lake Winnebago. "This is crazy (the open water in Lake Poygan), the wind is keeping it open, sometimes this happens on Lake Poygan but there's a big open spot out here," Herman said. He said that there's about 17 inches of ice on Lake Poygan in the spots that aren't near the open water. This is more then enough for cars to drive on and Local 5 News saw lots of people ice fishing on Lake Poygan on Thursday afternoon. All-Canada Show returns to Green Bay at Oneida Casino promoting best fishing & hunting spots "You got to pay attention, I wouldn't go out at dark unless you know where you're going (and I wouldn't go out on the ice) during a fog unless you have GPS," said Herman. Lake Poygan is a popular spot for sturgeon spearing and the Wisconsin Department of Natural Resources has a lottery system to limit the number of people that can hunt for sturgeon on this lake. Sturgeon spearing season begins on Feb. 8. Herman said the ice on Lake Winnebago, another popular spot for sturgeon spearing and ice fishing, is looking really good right now. He says there's about 15-17 inches of ice on Lake Winnebago. Outagamie Forage Council Annual Meeting "Lake Winnebago the conditions are great, probably the best in six, seven, eight years," Herman told Local 5 News. "Ice conditions are going to be really good for all of those events." Herman said normally its Lake Poygan that has better ice conditions than Lake Winnebago, but this year the trend reversed itself. Herman and other local authorities remind people that ice is never 100 percent safe. Many local fishing clubs post ice conditions on their social media pages.