West coast USA ,best time of year to go

Just thought I'd seek some opinion from you knowledgable lot on the best time of year to do a little road trip including the obvious,San Fran ,LA ,Las Vegas etc .
Never been to west coast so thought it was time to put that right , don't really want to go in the blazing summer heat nor want to go when it's its too cold , I know this subject has been discussed many times but as I'm out of my comfort zone I thought I'd ask what everyone thought .
Thanks in advance

Have been to SFO a few times but not anywhere else)

September was still a little too hot on a couple of days for me but my mate thought is was fine.

May was a tad chilly - especially in the evening and early morning but OK during the day.

November (2 visits) was fine - not too hot or cold. I have pics of me on the ferry across to Sausilito in short sleeves but I was also carrying a hoodie too as the wind can sometimes pick up.

May or October...can't go wrong

Hi Blacky

We always go to Vegas in April - we find it's comfortable to walk around in shorts & t-shirts and can even have a pool day but it's not overbearingly hot - my hubby really suffers in the heat

I'll let you know about LA and San Francisco in 92 and 99 sleeps respectively!

With best wishes

ScoobySu

Last year (2014), we travelled from SFO to Las Vegas in June, via a number of places. We found San Francisco to be OK, but certainly not warm. Sacramento was lovely, Lake Tahoe a bit cooler (but is at 6,000 ft). Yosemite was perfect. Death Valley was up to 116F, which was a bit warm for June, but then if you go there you would be disappointed if it wasn't hot. Finally Vegas was over100F, which I think was above average for June.

I think May would have been a bit better, but then you are taking chances with snow on the Tioja pass in Yosemite, if that is on your itinery.

We did that trip a few years ago and went in early May, the weather was just about perfect everywhere. You do get the mists rolling in, in SFO we had a really lovely day clear and 72c at Alcatraz , day of our tour of the city on the bus was marred by high winds and low cloud.

Vegas can get very hot in later May, but if you like 80 to 100 then not a problem. Death Valley apart from now is about the same 100 plus every day, it can get unbearable for walking and getting out of the air condition car can be a killer.

Went in early/mid June 2012 to all three cities. San Francisco was by far the coolest at around 15C needing long sleeve clothing. LA was OK hoovering around 20C with just a short sleeve but got cool in the evening. Las Vegas was boiling hot hitting 40C.

In California, July, August and September can be hot inland. San Francisco and the coast down to Santa Barbara can be cool(and overcast) in June through August because of the Pacific Fog. May and September are often the best months weather wise.

Coldest winter I ever spent was the summer in San Francisco comes to mind

Even though I'm in Palo Alto right now, it most definitely isn't warm. We are usually averaging around 21-25 in the summer but right now heating is most definitely required as its only hitting 16-18C in the day and 3-6C at night. When the sun comes out during the day, it feels great but still jeans, hoodie, shirt weather. I generally find SF not particularly warm unless July/August/September time however that is somewhat balanced out by the afternoon fog incursions bringing the temps right back down.

My vote goes for May, June, September, October.

September

Coldest winter I ever spent was the summer in San Francisco comes to mind

Even though I'm in Palo Alto right now, it most definitely isn't warm. We are usually averaging around 21-25 in the summer but right now heating is most definitely required as its only hitting 16-18C in the day and 3-6C at night.

When they come over to visit, my Central Europe employees seem to enjoy these temperatures in December and January, tho'

mid-May to mid-June and September, yeah. You will need to plan a bit for temperature variations no matter when - in summer the difference between my place (I'm pretty much smack in the middle of SF) and Palo Alto or Berkeley alone can be 15 degrees easily and with the places you're looking to hit it may be more extreme. These time windows will let you do coastal experiences without needing to deal with the marine layer - you'd feel silly coming all the way out to SF and not being able to see the Golden Gate Bridge (I'm not kidding).

September for San Fran & LA. October for Las Vegas.

Thanks for all the feedback everyone , April/May is a bit too soon for me so think I'll plump for sept/oct .
Time to get planning the trip

September for San Fran & LA. October for Las Vegas.

That's exactly what we are doing

I looked into this before booking. Blacky, if you are looking to drive down the coast as we are, then the summer months can get quite foggy. Late September was a winner based on what I've read, and the added bonus for us is that our trip will cover OH's 30th

Enjoy planning/booking, and we might bump into you in CA

Another vote for September, although avoid the labor day weekend

Avoid May or June for coastal California, It is often cold and foggy in these months, even has it's own name "May grey June gloom." Vegas can be very hot in July and August, although I went in August last year and it was only low 80's. Late September would be my choice, California is still warm but Vegas is beginning to cool down.