How hot is it in the tube today?
Predicted Underground platform temperature, line by line.
Hotter on board
Cooler on board
vs street level
The District, Circle, Hammersmith & City and Metropolitan lines are shown as a single "Sub-surface lines" figure — why one number, not four.
London clay absorbs heat slowly over weeks and releases it just as slowly — which is why the deep tube can still feel stifling days after a heatwave has broken, long after the streets above have cooled.