Hottest: 108*F on my bike computer.
Coldest: estimate -25*F - the bike computer only goes down to -19*F, it was pegged there the whole time and parts of my ride are always a few degrees colder.
Windiest: Heck, how should I know? It's just "windy" - I don't have an anemometer on my bike. I'd guess 30 MPH steady headwinds with perhaps 45 MPH guests.
Rainiest: Really heavy, drenching downpours. Not often, but once a year or so.
One time, with pea-sized hail.
Snowiest: 12" on the ground, unplowed, going through car tire ruts, with it still snowing heavily.
Smoggiest: N/A - air quality here is in the top 10 percentile nationwide.
Pollen: Also N/A because it doesn't affect me. I grew up on a farm and honestly had never heard of allergies until I got to high school - I never saw anyone who had them before that. I can swim in the stuff and not notice.