A mini-heatwave is forecast for week one of the Easter school “holidays”, with temperatures in the mid-20s.
Britain will be warmer than Sydney and Los Angeles, with the fine weather set to last into the weekend and beyond.
Such a fine spell usually sparks a rush to the coast and countryside – but self-isolating Brits will have to make the most of it at home instead.
Police repeated warnings that people must not sunbathe or picnic in public.
The mercury hit 22C in London over the weekend due to a plume of hot air from Africa.
It is now forecast to soar even higher, peaking at 24C on Wednesday and Thursday.
Most areas will enjoy above-average temperatures.
The Met Office said: “Over the Easter weekend there should be a lot of dry, settled weather with sunny spells.
“The South should be the warmest and driest, with the greatest chance of rain and high winds in the far North.
Beyond next weekend this pattern is expected to continue, with dry weather dominating.”
The Met Office also warned hay fever sufferers to expect a high pollen count.
As the fortnight-long Easter holidays for pupils begins, most schools are staying open to care for the children of key workers and the vulnerable.