I'd caution against looking at continuing rain in late spring and early summer as good news. (Yes, in the big picture, it is good for the long term water reserves)
I'd also caution against such massive generalizations such as "most of the farmers haven't even started working the fields yet". For example, where I live (west of Sacramento, in prime Central Valley farm area) the fields are almost always being worked to some degree. Right now on my drive home from work every day I see strawberry, sunflowers, corn, and tomatoes.
CA is a massive state and the farming conditions, needs, and seasons vary just as massively.
But for farmers its a very mixed bag. The wet springs have a lot of farmers here worried. Some crop planting have been delayed, others already planted may have lower yields do to the unseasonal rains.
Of course, there are others for whom this has no bearing or may be good.