The short answer
The best time to pave in Northern California is typically spring through fall, when the air is warm and the weather is dry. Asphalt needs adequate temperatures to be placed and compacted properly, and sealcoating needs dry weather to cure, so rainy winter days are usually avoided.
Why temperature and moisture matter
Hot-mix asphalt has to be placed and compacted while it is still warm. In cold air it cools too fast to compact well. Moisture is just as important: wet bases and rain-soaked surfaces do not bond or cure properly.
Spring: book early
Once the rainy season ends, schedules fill up quickly. Booking in late winter gets you a spot as soon as the weather turns.
Summer: reliable weather, hot surfaces
Dry weather makes summer dependable for paving and sealcoating. Very hot days can keep fresh surfaces soft longer, so keep vehicles off new asphalt longer than usual and avoid turning the wheel while stopped.
Fall: a sweet spot before the rain
Early fall is a popular time to finish repairs, fill cracks and sealcoat ahead of winter rain, so water cannot get into the base during the wet season.
Winter: possible but weather-dependent
Dry winter stretches do occur in the Valley, and some repairs can be done, but jobs may shift with the forecast. Foothill locations can see colder conditions than the Valley floor.
