The National Weather Service has announced a frost advisory covering Napa and the North Valley region, as near-freezing temperatures are possible Friday and Saturday nights.
The advisory is in effect from 2 to 8 a.m. Saturday in the interior North Valley, due to a cool air mass settling over Northern California on Friday. The coldest temperatures are expected in the hours immediately before sunrise.
Homeowners are advised to cover outdoor plants or take them inside to avoid frost damage.
Overnight lows early Saturday morning are forecast to reach 33 degrees at Napa County Airport under partly cloudy skies and a light south-southwest wind. Areas of frost are expected to linger through 10 a.m.
The weather service lists a 40 percent of overnight showers, likely before 4 a.m. An overcast morning is expected to give way to a mostly sunny afternoon with a high of 59, before the return of frost after 10 p.m. and a Saturday night low of 37.
Here is the five-day temperature outlook for Napa:
Saturday: 59 / 37 — 20 percent chance of showers before 10 a.m.; frost possible before 10 a.m. and after 10 p.m.
Veterans Day: 62 / 44 — frost possible before 10 a.m.
Monday: 64 / 46
Tuesday: 65 / 45 — slight chance of rain
Wednesday: 63 / 44 — chance of rain