In cold weather, sensor on garage door opener malfunctions
In the USA, there are usually two &quot;sensors&quot;. An optical sensor near the floor to detect obstructions and a motor current detector to sense force. You can usually adjust the force, but if you increase it you may defeat the safety mechanisms. Read your instruction manual carefully.
Most garage openers have a shuttle that rides on a rail. There should be an emergency handle to disconnect the door from the shuttle so you can open/close the door manually without power. With the shuttle disconnected, test the door for binding. It may only require lubrication.
The springs should balance the door such that only a small amount of force is necessary to open and close the door. If the springs are strongly pulling the door up or down, hire a professional to adjust them. This is not a DIY job, the tension is enormous and you can seriously injure yourself.