Fog occurs on a regular basis-this is why the trees thrive.
I love Redwoods NP. I really like James Irvine Trail all the way to the ocean(passes thru Fern Canyon too). This is from Praire Creek Visitor Center.

Fog - but probably no rain or not much anyway. Our weather has been wacky the past few Junes. Our roses have had problems growing because of colder-than-normal Junes. During "bad" periods, you may see very little sunshine along the coast.

Stu Dudley

I would go in June. We've had rain in May even if infrequently, and at least in the SF area, June tends to be less foggy than July and August.

http://www.flickr.com/photos/mksfca/sets/72157631954074484/show/

Is your heart set on driving to the most northern part of California? If not (in case you don't know), there are several places to visit the redwoods much closer to San Francisco and the stretch of Highway 1 just south of San Francisco (which passes through Half Moon Bay) is as spectacular as other parts of the highway.

HTtY

All good advice above. With 10 days after Memorial Day you could extend your trip up US 199 to Grants Pass Oregon and go through the south entrance of Crater Lake National Park.
You probably won't be able to stay at the Lodge but you can drive back and stay in Medford. You will still see some snow next to the roads in Crater Lake NP but the view of the lake is beautiful. San Francisco (or Napa) is an easy days drive from Medford using I-5.
The north entrance to Crater Lake (off Rt. 138) won't be open until early July.

Thanks to all for your advice.I previouusly driven Hwy 1 from San Luis Obispo to San Fransisco. Have been to Muir Woods and have seen Crater Lake on a previous trip. The main thing on this trip is to go to Point Reyes to hike around and then just enjoy beautiful scenery and do at least one hike per day while driving up the coast. Redwood National Park seemed to be as good as place as any to turn around. I just found out about the Lost Coast drive that I must do. It might take me a week just to reach Redwood National Park!

To get to the Lost Coast from the south, one needs to take the Usal Road shortly after CA 1 turns away from the coast north of Fort Bragg. Unfortunately it is not well marked. It is a dirt road that climbs steeply off CA 1 and can also be deeply rutted and inappropriate for two-wheel drive cars--it depends on the season. Type Usal Road, CA in Google map and it will locate the road north of CA 1, but playing with the map will give its location and the type of turn necessary to enter it.

The Best Western in Garberville is a good place to stay in the Redwood area. The people are welcoming, the rooms are big, breakfast is good, and there is a wine and cheese reception every evening.

HTtY

PS When we were at Point Reyes earlier this month, I was surprised how far the road is from the ocean and that we had to take a bus to get to the lighthouse.

When we were at Point Reyes earlier this month, I was surprised how far the road is from the ocean and that we had to take a bus to get to the lighthouse.

Only on weekends during whale watching season, or that is what the ranger told us a couple of weeks ago.