We want to primarily avoid the cruise ship crowds and throngs of tourists descending upon the city during high season.

We live in San Francisco and I imagine that Venice in late autumn (mid-October) probably has a similar climate. I could be mistaken.

My wife detests cold and especially the combo of wind + cold. I know we can't get it all, but I'm trying to determine what would offer the best of both worlds; ie. decline of tourists but also relatively mild weather and sunshine. We'll be in Vienna and Salzburg for a week afterwards, so I'll have to check the climate there as well. I imagine it will be a lot cooler in the mountains. Hopefully no snow that early in season though!

The other concern is flooding, though I'm told it's really just a minor inconvenience for several hours at worst, if we encounter it at all. Is this something we're likely to expect in Venice in October? The thought of cool winds and rainboots doesn't appeal strongly to the missus. The circus of tourists in summer months even less, to me.

I assume that all museums, palazzos, trattorias and osterias, etc. stay open year-round at reasonable hours, despite low season; correct?

What's the ideal middleground then? Should I plan for April or October?

Sweater and trench coat weather is fine, but heavier winter coats isn't really what we want for this trip.

Is there a particular week in Spring that sees less tourist traffic? Would late-March be more ideal than October in terms of crowds and climate? What about the risk of flooding? Google Images "Venice in October" and you'll understand my concerns.

What's the general cut-off in September for tourism? Would we be alright to travel by the last week of September or is it still pretty packed with vacationers trying to get a last breath of summer in? Honestly, the October floods worry me more than the cold, though it would be nice to be able to sit outside at a caffe in the early mornings and evenings without the chilly winds. At least if travelling in Spring, we could avoid crowds by spending evenings and early mornings touring without the effects of the cold. If a chilly night in Venice drops to around 10°C (or below with windchill) and the streets are flooded due to high tides, I imagine the missus would not enjoy walking around late at night, which looks to be the most intriguing time to explore the city streets. I'd really appreciate some advice from those who've travelled to the city in either Spring or Autumn.

Thanks so much!