North London and Hertfordshire woke up to a thin carpet of snow this morning.
A yellow weather warning of ice and cold weather is in force across the boroughs, but no more snow is expected to fall today.
Drivers are being warned to take extra care on dangerously icy roads and people are being told to expect delays.
There are currently two lanes closed at Potters Bar on the M25.
London Underground is running smoothly, with only the central Line part suspended.
But commuters traveling on Thameslink Govia’s London to Bedford line through Elstree & Borehamwood, Mill Hill Broadway and Hendon are expected to experience a miserable journey due to major delays.
According to rail bosses, a water main which burst last Friday is still causing problems across the track meaning trains will be four coaches instead of the usual eight.
The news is likely to irritate passengers, who have experienced nothing but problems across the line for more than one week.
People are being told to take a rail-replacement bus, which will run through Radlett, Elstree and Borehamwood and Edgware.
Despite the bitterly cold conditions, temperatures will rise to 4c today.
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