If you were are looking to do a side walk and front stoop i would have to suggest doing it as soon as the weather breaks. most years the second or third week in march . If you were doing a pool deck i would say open up the pool earlier then memorial day ,late march early may into the beginning of June , patios, stair ways and any other place you can have an overlay done anytime over 41 degrees. the key factor is the temperature you don't want it to be too hot or too cold mostly for the sealer to work right also when there is less then 60% chance of rain you want to be careful not to rush it . If you have a project to do chances are you have thought about it for at least 10 days so keep in mind to Waite another day or 2 till it warms up cools off or just dries up it is definitively worth waiting for .