A combination of a few things will bring chilly overnight temperatures this weekend. First, we remain under the influence of northerly flow in the upper levels of the atmosphere, which typically supports cooler temperatures overall. We'll also be watching for an incoming cold front that will arrive late tonight or early tomorrow. While it brings a few light showers this evening, by Saturday evening low temperatures will be dropping into the mid 30's. You'll want to bring in or cover any sensitive plants with frost looking more and more likely. By Sunday night the atmosphere will be primed for optimal radiational cooling, which will again bring temperatures into the mid 30's. We will have mainly clear skies and light winds into Monday morning.
At least there is a light at the end of the tunnel, with a forecast high of 72° on Tuesday.