When it comes to running, warming up before every outing is very important. Start with a few minutes of walking and then progress to a slow jog to begin. Gradually increase your speed to get your heart rate up.
Depending on the type of training you did over the winter, you might want to consider starting your outdoor running regime gradually, alternating between intervals or running and walking.
Someone who was quite sedentary over the winter may consider starting with intervals of 1 min of running followed by 1 minute of walking, repeating this sequence 3 to 5 times at the beginning. Someone who has been running inside regularly may consider starting with intervals of 4 minutes of running followed by 1 minute of walking when transitioning to the outdoors.