It's been a mixed night for Labour but really they should have done better against a divided Tory party.
But on the subject of bad days... The Conservatives were soundly trashed four years ago and made further losses in this round. More than Labour, even. Their second place in Scotland only looks good because it's unexpected, but still only patches up the truth that at the moment Scotland is a one-party nation with a couple of also-rans; the SNP won more votes than Labour and the Tories put together (at the constituency level; in party lists Lab+ Tory just barely edge ahead).
In Wales the Conservatives came third behind Plaid Cymru overall -- losing to a nationalist party in a country where nationalism really doesn't matter to most people.
In London, the Tories tried their hardest to drag Sadiq Khan's name through the biggest pile of s*** they could find, and he's come out clean on the other side over their man Zac.
And, across England, Conservatives are obliged to hide behind the old mantra of local elections being votes against the incumbent government in order to hide their poor performance. Non-party Labour have lost 24 councillors and one council, it is true. The Tories lost 33 overall so far; and starting from a massively lower total already at that.
It's been a bad day for Labour, but while the Tories point and laugh, they might do well to look at their own messy house. Neither of the two main parties comes out of yesterday with anything to celebrate much. Labour didn't implode, which is in itself remarkable, but despite the "circus party" of Labour being the main opposition, the Tories went backwards.
The only two parties to do well out of Thursday are the Lib Dems, for some reason, and UKIP. The latest round of elections have seen just another shift away from mainstream politics in general.