However, this can be dangerous when salt is applied to some snow and melts that snow, because then, if the overnight temperature drops below 15 degrees, that snow melt (which essentially becomes a saltwater solution) can refreeze into a layer of ice.

Ammonium sulfate will melt ice down to 20 degrees F. The downside for this treatment is it may put pits in your concrete if you use too much or it sits on there too long. Potassium is another good chemical to sprinkle on your sidewalk if temps are below freezing and above 20 degrees.

“Regular rock salt ice melt only works down to 20 degrees, so there’s other ice melts that work down to other temperatures. Like your calcium chlorides, your magnesium chlorides will melt ice down to a lower temperature, down to -30 degrees” said Carl Combs of Rocky’s Ace hardware in Springfield.

At temperatures below 32°F (0°C), liquid water freezes; 32°F (0°C) is the freezing point of water. At temperatures above 32°F (0°C), pure water ice melts and changes state from a solid to a liquid (water); 32°F (0°C) is the melting point.

Salt has proven itself as the most effective cost-efficient melting material for icy or snow-covered roads. However, as the temperature falls below 10-15(degrees), salt loses its melting power and becomes ineffective.

There is a quantity called the Accumulated Freezing Degree Days, or AFDD. Freezing Degree Days (FDD) are simply the freezing temperature minus the daily mean temperature. The AFDD is the sum of the daily computed freezing degree days.

a measure of how cold it has been and how long it has been cold; the cumulative fdd is usually calculated as a sum of average daily degrees below freezing for a specified time period (10 days, month, season, etc.).

32° Fahrenheit

4 inches

A tenth of an inch of freezing rain becomes a nuisance. It’s not enough for power outages, but it can cause sidewalks and overpasses/bridges to turn slick. A half an inch of ice damages trees. Widespread power outages become more likely.

Using a ruler, measure the thickest part of the ice, from the edge of the object to the edge of the ice. Then measure the thinnest part of the ice the same way. Lastly, add the two values together and then divide by two. The resulting value is your ice accumulation.

If less than a quarter-inch of ice is produced, it’s usually more of a nuisance event with less severe impacts. However, it’s important to remember that even a light glaze of ice can make travel hazardous.

Just to give you an idea, a layer of ice that’s a fourth of an inch to half an inch thick can break smaller branches. It would take half an inch of ice or more to break a large branch. But, the amount of ice isn’t the only consideration—some tree types are more tolerant to ice damage.