As it warms up there are several things to keep in mind for your grass. Outstanding of feeding and watering it correctly, how you mow it is important as well.  When it is hot outside you actually want to cut your grass taller for several reasons.  First you don’t want to expose the root system and have it get stressed out from the heat.  Taller grass will offer protection to the root systems as well as shade from the heat.  If the roots are healthy then the grass will grow thicker leading to a better overall lawn.  Hope this helps!