Having trouble starting the car, especially during cold winter?

I’ve been having trouble starting the car, especially during cold winter temperatures. A week ago, I started the car in the evening, and while it started fine, it struggled a bit, taking a few extra seconds to turn over. The next morning, it had trouble starting again, and it took about an hour and a half before it started normally.

Last night, I started the car again because of the cold temperatures (around -18°C), but this morning it wouldn’t start at all. The fuel level is above half, and I’ve ruled out leaving lights or other accessories on for long periods.

The car makes a clicking sound when I try to start it, as if it’s struggling to turn over, but it doesn’t fully start. Could this be related to a weak or failing battery? I would appreciate your help in diagnosing and advising on the best next steps.