For many of us, exercise is routine. But before it becomes a habit, you need motivation. So, think of why you want to run: Do you want to live longer? Lose weight? Boost mental health? Build up to a 5k or a marathon?
Concentrating on the benefits will help you get over the motivation challenges in the early days (and possibly the cold mornings!). Eventually, the need for motivation diminishes when routine takes over. Habit formation can take anything from days to months, depending on various factors (like the individual and the habit itself). So, at worst, if you start exercising regularly in January, it could be a habit by March.
Another form of motivation is a goal or a deadline. For instance, you might want to sign up for a 5k fun run or race that’s taking place in a couple of months. That becomes something to build towards.
Write your motivation down and keep it somewhere visible. Tape it to your fridge if it helps!