The cold weather can cause your transmission system to have a low line pressure by freezing and leaking fluid from the transmission seals. When a transmission has a low line pressure it can mean multiple things such as inadequate fluid within the system, slipping transmission, and improper function of gears.
Can cold weather make your transmission slip?
Cold weather causes the parts of the transmission to contract and sometimes the gears can freeze which leads to slipping. Cold temperatures cause the fluid to thicken which means it can't move around as freely to do its job.
Is it bad if your transmission slips?
Transmission slipping does not always mean your transmission is going to fail, but it is a signal that maintenance is required. Because your car's transmission is one of its most complicated systems, it is important to accurately diagnose the cause of the symptoms.