Why is the pavement wet when it hasn’t rained?

Credit: DaytonDailyNews

caption arrowCaption
Chief Meteorologist McCall Vrydaghs explains.

Credit: DaytonDailyNews

For the past few days, the pavement has appeared wet, but there is no sight of rain.

Storm Center 7 Chief Meteorologist McCall Vrydaghs has followers on Facebook who are asking why.

Chief Meteorologist McCall Vrydaghs I have a question; Why are pavements, sidewalks, etc wet? It hasn’t rained. We’re stumped!

Posted by Natalie Jones on Thursday, December 26, 2019

After Vrydaghs did some digging, she two possible reasons it could be happening.

Due to the wet ground caused by recent snow melt, it’s possible water could be seeping into the concrete. Vrydaghs said this is called “sweating,” and is caused by hydrostatic pressure pushing water and moisture through the concrete from below the surface.

The more likely cause is that the concrete is colder than the air, causing condensation, making it appear wet, Vrydaghs said.

About the Author