Weather in Big Sur can vary by more than 30°F / 16°C between different locations at any given time.  Accordingly, consider bringing clothing for a variety of temperatures.  The climate is mild Mediterranean, generally cooler in the valleys and hotter in the Santa Lucia Mountains.  Wind often blows ashore in the afternoon, occasionally with force.  

Big Sur weather forecasts:

National Weather Service

AccuWeather

The Weather Network

Surfline

The Weather Channel