Time once again to remind riders in the north that even if the sun is still up, its low angle may blind drivers so they don't see you.
With the sun at your back you may forget that an oncoming driver will have to squint into that glare. Just as an oncoming driver may turn in front of a cyclist in dusk or darkness, so might a dazzled driver hook a turn in the middle of what looks to you like a clear, bright afternoon.
As funny as it sounds, be extra alert when the weather is really nice. As the autumn advances, the sun stays at low angles for more and more of the day. A little light overcast can be your friend.