Moose Jaw residents may wake up to some crystalized grass on Saturday morning, as temperatures are expected to hover around zero overnight with the possibility of frost for the first time this summer.  

Environment Canada Meteorologist, Terri Lang says the freezing temperatures are due to cold air mass that is sweeping across the province.  

“We are expecting generally clear skies and dry air,” says Lang. “All those conditions combined will make for patchy frost, it’s probably not going to be a widespread killing of frost, but in low-lying areas it's possible.” 

Friday night will definitely be a change of pace after overnight lows of anywhere between 15 to 25 degrees throughout most of the summer. It’s safe to say that the expected overnight low is very unusual for this time of the year, but not irregular. 

“The record temperatures for this time of the year are –5 to –6 [degrees] would tell us that this has happened in the past. The average frost for Moose Jaw, like a killing frost, is September 18th so we’re kind of getting into that zone where it’s possible.” 

Overnight lows will continue to be in single digits moving forward, which can be contributed to two factors – one of them being the longer evenings.  

“We’re losing daylight each day and that allows the earth to cool more as opposed to those shorter nights. As well the air is quite dry, a change from when we had more humid conditions and when the air is quite dry it can cool off quite fast.” 

Lang concluded by saying that as overnight temperatures continue to drop, especially on Friday, people should look to take the proper precautions to protect their plants or garden from the frost.  

The first day of fall is Sept. 22.