I remember being on the top floor of the UCSB Physics Department and seeing snow on the tops of the mountains. But I never saw snow in Santa Barbara or Goleta during the ~35 yrs I lived there.

-Here's snow in the mountains in April last year:
watch here

-And in the mountains in March 2016:
watch here

-And in May 2011, from the top of a parking garage, but I don't see much snow - or any snow on the ground:
video

And longer ago:
The following cities have never reported a measurable snowfall… but have reported a trace (T) of snow:
San Diego, CA (T-1949, T-1967)
Santa Barbara, CA (T-1939))

Read more in this interesting site:
places never snows

I don't know. I am sure it will happen, but it's very rare. Normally to see snow you need to be in the Santa Ynez mountains.

Snow is pretty rare in Santa Barbara (at least where we live, and not in the mountains) but it looks like the last reported snowfall was in 1949.

Unfortunately, scientists don’t know when it will happen again. Meterology is the science of predicting weather, but current technology only allows specific predictions like whether or not it will snow about a week ahead. This is because it is incredibly complex! All sorts of things like the winds and ocean currents affect the weather which makes it hard to model and predict.

I saw that someone said 1949, but I was born in 1968 and I am now 51 in 2020. When I was a kid around 5th grade maybe, one day at school it snowed and they let all the kids go outside and play in the snow! It was awesome I'll never forget! I think I was around 10 or 11, so around 1978 perhaps? Sorry not sure, but it fully snowed when I was a kid going to school in SB!