A reported "freezing" level is the altitude where it is forecasted to remain below 32 degrees for the entire forecasted time period.SEATTLE - A reported "freezing" level is the altitude where it is forecasted to remain below 32 degrees for the entire forecasted time period. Thus, even though there are some mornings where you have frost on your lawn, we might report a freezing level of 4,000 feet since that is where it's supposed to stay at freezing all day.