Bright sunshine (and I remembered my sunglasses)
Blue sky
Set off a bit early, and it's half term, so the roads were somewhat de-populated of cars
Wore shorts and nobody laughed or vomited (I usually wear 3/4s)
And a driver in a black Audi waited patiently behind me as I cycled down the 'middle' of the road [out of the door zone of a row of parked cars], and once the other lane was completely clear, he overtook me by going completely over to that side of the road. Thank you, sir, for you consideration!