Mine comes in the fall. Easy enough to figure out why, I miss the foliage change and I get really depressed. Hits me in the springtime too, but not quite as hard.
After living on the other coast for 35 years, the last few years out here my body/mind want to reset to the different seasons, but the change is so minimal here I think it makes my system "hiccup".
Plus I see the few foliage trees you have out here sorta change color and I actually feel bad for them... good try though.
And as you can see by my ramblings..... the springtime depression has started kicking in.
Hang in there.. you're not alone.