When should you apply your lawn pre emergent 🤔

To prevent summer weeds, apply a pre-emergent herbicide once the ground temperature has been 55 degrees for at least 48 hours. To prevent winter weeds, apply a pre-emergent herbicide in the fall when ground temperatures reach 70 degrees and continue to drop.

[kwilliams]

When should I apply pre emergent if I plan on leveling off with sand?