If you planning to travel to Trefethen Family Vineyard, Napa, California, here is your 6-day travel weather forecast to make sure you have all the essentials needed during your stay. Start your day when the sunrises at 1:50 PM. The temperature feels like 53.050000000000004 with a humidity level of 71 so dress accordingly. Cloud coverage is 7 percent with visibility at 12.6 percent. Today’s UV index is 8, don’t forget the sunscreen if you need it! Today’s winds are traveling southwest at a speed of 3 MPH. At the end of the day don’t miss the sunset at 2:35 AM.