Yes, because there are different types of melancholia. Usually, autumn brings the one I welcome: I start living slowly, being more contemplative, taking time to read, etc. Melancholy is not always a negative thing, it is a potentially creative feeling. It started like this, it was feeling like autumn very early on actually, but since we have this quasi Indian summer, it messed up my state of mind. Today when I went out, I had to put sun cream on my skin! In October! And I had shades. Sure, the leaves were falling down, but the heat was so out of place. So I am not wearing warm, comfortable clothes and however light my clothes are I feel too hot anyway. I don't feel like eating hearty food either. But more importantly, instead of relaxing and gathering energy, I have my energy sucked off me by the heat. So I don't feel quite right all the time, I have difficulties to focus when I read and I have a taste for nothing.
On the plus side, it takes very little to change this state of mind: a change in temperature will bring back balance. And according to the weather news this will not last for much longer.