I'm relatively new at this fiction thing, but I've been writing long enough to know my moods affect my writing. When I'm upbeat and happy, the prose flows and I come up with some funny lines. But when I'm tired or down, I have to force the words onto the page only to wish I hadn't bothered.
What about you? Do your moods and energy level affect your writing? Do you write anyway? Or put off the word count until your sun comes out again?