Seriously I hate gloomy weather. It brings me down. I not only feel lethargic (which might be a commonly felt amongst people in such weather) but I also feel slightly depressed. Maybe I am exaggerating but maybe I am not.
I hate grey days. I totally do.
About SAD from Wikipedia -
Seasonal Affective Disorder (SAD), also known as winter depression or winter blues, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or, less frequently, in the summer,[1] repeatedly, year after year.
More at - http://en.wikipedia.org/wiki/Seasonal_affective_disorder