But sunbathers and groups were criticised on Wednesday morning, as grounds were left covered in litter.
Police were forced to break up groups of more than six, as friends and families “pushed the boundaries” on the easing of restrictions.
Nottingham city council leader councillor David Mellen said: “We have taken steps to prevent a repeat of the appalling scenes we witnessed at the Arboretum on Monday evening. Today, the Arboretum is closed along with Lenton Recreation Ground where similar problems arose.
He blamed the actions of a “thoughtless minority” for spoiling the joy of lockdown easing and said they would keep the restrictions under review.
He added that it was “unacceptable and unsustainable” for “thinly-stretched crews” to have to clear up the mess left behind at parks.
Andrea Leadsom MP responded to an image of Abington Park in Northampton, which showed beer cans and plastic cups scattered across the green, and said it was “unbelievable”.
This is what beautiful Endcliffe Park looks like today after one day of warm weather. Barbecues, clothes, booze bottles, and at least one wallet that people didn’t bother to take home pic.twitter.com/OdZgBjqR0j
Further footage shows London’s Hyde Park similarly littered on Wednesday, as was Primrose Hill, where Police placed a Section 60 order following violence and knife crime.
In Wales, rubbish was strewn across the steps of the Senedd in Cardiff Bay and the beach in Barry Island.
Steve Treharne, of South Wales Police Federation, said: “People have lost loved ones, people’s businesses have been affected and it’s really important that people are responsible so we can all get out of this together as safely as we can.
“As the rules are sort of relaxed there will be people who will want to push the boundaries and go beyond those boundaries into the next stage of what they can and can’t do.
“I’d just ask people to be a little bit responsible now as we come to the end of the tunnel.”
Richard McIlwain, Deputy Chief Executive of environmental charity Keep Britain Tidy, said: “Litter is a disaster for our environment and for the wildlife that we share these beautiful places with and so it is so important that people take some responsibility and dispose of their rubbish correctly.
“Walking away from the debris left after a picnic or sharing a few drinks with friends is not acceptable. It should be put in a bin and, if there is no bin or the bin is full, it should be taken home with you.”
Matt Hancock issued a warning on Twitter on Tuesday evening, saying: “Let’s enjoy the sun but let’s do it safely. We have come so far, don’t blow it now.”
His comment comes after the Prime Minister said he hoped people would take advantage of the “beautiful weather” to play sport or exercise, while also emphasising the country should still “proceed with caution”.
Met Office forecaster Alex Burkhill said it was a “possibility” that Wednesday’s temperatures could surpass the March record of 25.6C (78F), set in 1968 at Mepal in Cambridgeshire.
Mr Burkill said: “Temperatures could be a touch higher tomorrow (Wednesday) than they were today. Whether it will beat the 25.6C, I’m not so sure. It’s on a knife-edge.”
“It’s not out of the question, but I’m not expecting it to. It’s a possibility.”
Temperatures are forecast to hit 24C (75.2F) to 25C (77F), with the highest figures expected around London.