"Pinapple Express" is an ironic term for what is, in fact, days of shitty weather. There are waves of heavy rain. The air might not be that cold, but you will be if you're soaked.
11 degree water, on the other hand, is like out of the cold water tap. Not so great for outdoor activity. Add to that the windchill factor if you're running or cycling.
Clear, sunny weather and -3 degrees is better than pouring rain and 11 degrees.
Staying warm isn't much of an issue for outdoor activity. It's not hard to achieve: an extra layer, some head gear and gloves; being dry is more important.