If you planning to travel to Hetch Hetchy Reservoir, Groveland, 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 1:19 PM. The temperature feels like 70.05 with a humidity level of 33 so dress accordingly. Cloud coverage is 2 percent with visibility at 14.9 percent. Today’s UV index is 9, don’t forget the sunscreen if you need it! Today’s winds are traveling south-southeast at a speed of 7 MPH. At the end of the day don’t miss the sunset at 2:45 AM.