Weather like high humidity all the time, after afternoon can be pretty cold until next morning, and I recomened you must spent couple of day to yosemite national park , no regret all about it.
It probably won't rain, but there have been years when it's rained a lot in April. So, don't forget your umbrellas. As I write this it has rained today (3/10) and will rain tomorrow.
It's very cold. A low of about 40 degrees and highs in the low to mid-50s -- Alright, we're weather wimps. Last night we had snow down to 500 feet. This was so unusual that everyone was talking about it and it made all the newscasts.
Bring clothes for cold weather and warm weather, but probably not hot weather. If you stay in the city, you can expect 50s to high 60s. If you venture North, East or South, it can get warm, let's say up to high 70s. If you venture West, bring your scuba suit.
Folks around here tend to think of dressing in layers.