Hi - I checked the weather and it is sunny this weekend between SFO and Seattle. I am not an expert driver but an okay driver and have driven to Lake Tahoe on sunny days. I want to know whether I should choose I5 or 101 ? WHich route is going to be more safe this weekend? Also, I want to have a stopover. I am open to all suggestions. Thanks

SFO is an airport and San Francisco is a big city. Why not just fly to Seattle? Another (maybe better) option might be to take the Amtrak Coast Starlight overnight from Emeryville to Seattle or Portland.
It takes quite a lot longer to drive US 101 than I-5. Your logical stop along I-5 would be Ashland or Medford Oregon. How long do you intend to stay in Washington or Oregon?
By the way, welcome to Fodors!

Thank you Tomfuller. Actually, I have to take my car to Seattle as we are moving there. Yes, US 101 will take longer and that's fine. What I am looking for is a safe drive. I am a new driver (not very new though). Weather wise, today and tomm are looking good. But anything else in terms of safety, that I am not aware of (snow, wind, sharp turns, narrow roads) and hence this question.

Welcome to the PNW! I really prefer driving US 101 going southbound. The scariest part of I-5 for me is north of Mountain Gate to Weed. There is a big bridge at Lakehead and a lot of sharp curves that you must slow to less than 60. If you go with US 101, you might not make it into Oregon before stopping for the night.

Between San Francisco and Seattle using US 101 on my preferred route is around 3 hours slower (wheels turning) than using I-5, but at this time of year that differential can be negated by poor weather over the Siskiyou Mountains on the California/Oregon border. Here's a map with my preferred route - https://goo.gl/maps/yhbxVeUbLopPkrSd6

This route takes you north on US 101 all the way through the redwoods and into Oregon. At Reedsport, Oregon, you'd take Oregon Hwy 38 east to its junction with I-5 near Cottage Grove, then north on I-5 through the Portland area and on to Seattle.

US 101 is mainly divided highway (with a few undivided stretches) all the way to the Eureka area. There are some stretches through the redwoods between Eureka and Crescent City where the road is a little twisty - not unsafe at all, but not especially fast. Watch for truck traffic. Once you cross into Oregon, US 101 is a fast undivided highway, quite scenic in spots. OR 38 is two-lane but also quite scenic, then once you reach I-5 near Cottage Grove, it's back to freeway all the rest of the way.

Google's "street view" is a terrific tool to get a preview of what a driver's-eye view of the road might be; here are a couple of samples from this drive.

US 101 between Eureka and Crescent City - https://goo.gl/maps/Q9aj42rxPhD9KE4FA
US 101 along the Oregon Coast, not far from Gold Beach - https://goo.gl/maps/Ev4brYU7xqo8XJS77
OR 38 just east of Reedsport. The area on the right is a wildlife refuge where you'll probably see some Roosevelt elk - https://goo.gl/maps/p83Mcg98ocM1PDMr8
OR 38 a little farther east, where the road parallels the lower Umpqua River - https://goo.gl/maps/LBQ1jioa4h1Juqzb8

Now if you choose the I-5 route instead (map - https://goo.gl/maps/A4tF2kzCKSG7eeXu6 ) the areas to watch out for are the Siskiyou mountains, roughly between Redding and Ashland, Oregon, and some low passes in the hills between Medford, Oregon and Roseburg, where black ice can appear overnight, making things treacherous. I looked at the forecast and there doesn't appear to be any snow in the forecast for that area for the next few days, so if you want to go that route you ought to be okay. I would advise not driving after dark or in the early morning hours in order to avoid icy roads. This is not as scenic as the coast route, but as long as you can avoid snow and ice, it's not at all challenging from a driving point of view. Boring, maybe.

Good luck!

Thank you, Tomfuller again

Thank you Gardyloo for such detailed and valuable information

We do this drive a lot since we are based in Seattle and spend most winters in Southern CA. Here is a link to the webcams at the Siskiyou Summit you might find useful. But I suspect you are on your way by now.

I-5 at Siskiyou Summit, Oregon Road and Traffic Cam