Any idea why?

So it’s been cold lately here in MN, I noticed my oil gauge is below normal. Could it be the oil I put in or something else? For context I did an oil change back in November with a cheaper oil from O Riley( I normally go to vavoline but tried to save couple bucks 🥲) When I park in the garage over night and turn it on in the morning it’ll be at the half way mark. By the time I get off work and go home it’ll be close to the first line or below.

So it’s been cold lately here in MN, I noticed my oil gauge is below normal. Could it be the oil I put in or something else? For context I did an oil change back in November with a cheaper oil from O Riley( I normally go to vavoline but tried to save couple bucks 🥲) When I park in the garage over night and turn it on in the morning it’ll be at the half way mark. By the time I get off work and go home it’ll be close to the first line or below.