Lower elevation areas such as Mogollon Rim and Flagstaff-Williams lakes will only be safe if the conditions in the area have been steadily cold. It is not uncommon for Arizona's winter nights to reach 0 degrees accompanied by day temperatures in the 40s, 50s, and 60s. Temperature fluctuation can produce effects in ice making its structural integrity questionable. Ice which looks thick and solid may actually be riddled with water pockets and soft spots. When choosing a place to fish, there are a few things you need to look out for before you cut.
Slush ice is about half as strong as clear blue ice, while new ice stronger than old ice.
River ice is 15 percent weaker than lake ice. As stated above, conditions are most hazardous when alternately freezing and thawing occurs. Continuous travel over the same route will weaken the ice. Remember to cut only small holes in the ice, preferably less than 10 inches in diameter. The holes should be large enough for a big fish, yet small enough to ensure a person cannot fall into it.