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Science behind icy sidewalks: How winter sun angles affect slickness of sidewalks, parking lots

KSHB 41 Meteorologist Jeff Penner explains how sun angles affect the slickness of surfaces after winter storms
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Winter sun angles

KANSAS CITY, Mo. — We see it every year: The ice and snow that occurs during the winter often make roads slick and hazardous, causing many crashes.

But, the ice and snow does not discriminate, as it makes sidewalks and parking lots slick, as well.

So, make sure you're not *just* keeping your eyes on the road, but also on the sidewalks you walk every day.

It's also important to know what direction your home or apartment faces.

Did you know that the slickness of a sidewalk or parking lot can be affected by what side of a building they are on?

During the main winter months of December, January and February, the sun angle is at its lowest of the year in the southern sky.

winter solstice sun angles
The sun angle at noon on Dec. 21, 2023, in Kansas City will be at 27 degrees.

At noon on Dec. 21, the angle is 27 degrees; at noon on Jan. 21, it is 31 degrees; and by Feb. 21, the sun angle at noon increases to 40 degrees.

On March 19, 2024, the first day of spring, the sun angle will be 50 degrees, and on June 20, 2024, the first day of summer, the sun angle will be 73 degrees.

summer solstice sun angles
The sun angle at noon on June, 20, 2024, in Kansas City will be at 73 degrees.

This creates an effect where the south side of any structure sees direct sunlight during the day, while the north side does not see any sun at all.

sun angles winter weather special
The angle of the sun in the winter in Kansas City makes it so that the south side of buildings receive more sun than north-facing sides of buildings.

Because of that, the south side of a building can be much warmer during the day than the north side.

If there is ice and snow on the ground, it is possible for the snow to melt on the south side while remaining frozen on the north side as temperatures can vary up to 50 degrees between the north and south sides.

Keep this in mind when you are walking out of your house or apartment. The south side may be the safest.

But, always look where you are walking, especially when ice and snow are on the ground. You may be able to avoid injury and years of pain.