Twenty-seven degrees. London boils, sweats, shimmers in a heat-haze. Tarmac oozes and melts.
Everywhere ants are on the move, while greenflies swarm in the sticky shade beneath trees and tickle the sweat on bare arms. Fledgelings feast on them, begging beakfuls from harried parents by dint of a blur of wings and their insistent churrs.
It's top-down weather, stereo on - though the arterial roads are busy and nobody's getting anywhere fast. Dogs pant; blood moves warm and slow beneath hot skin slick with lotion. Barbecues send cooking smells and smoke to blanket the city in a swelter of car exhausts and mirages, and above it swifts ride the thermals, screaming high and faint, far overhead.