The BBC news and sport pundit, 43, took to social media to express his disappointment.
He shared a photo of rubbish littered across a park, with his pet dog lurking nearby.
Sharing to his some 139,000 Instagram followers, Dan expressed his dismay.
He wrote: "Another beautiful day in Sheffield but this is so frustrating."
"Think of others"
After adding several angry face emojis he continued: "Find a bin. Take it with you. Think of others. #PickItUp."
Dan's followers overwhelmingly agreed with his sentiments.
One user wrote: "Shameful. Need to start a new 'keep Britain Tidy' campaign."
A second user commented: "And we are told that the pandemic has increased community awareness, really? From my own area there’s more litter and dog fouling etc."
A third user lamented: "I absolutely love how many carrier bags there are amongst this rubbish... wouldn't common sense tell you to put the rubbish in it and find a bin at the very least."
And a fourth user complained: "Just can't understand people. Bag it up and put it in your car or carry it home. It's not difficult!!!"
The current heatwave - coupled with the lockdown easing - has led to thousands of Brits flocking outdoors.
Unfortunately a very noticeable side effect has been masses of rubbish appearing in public areas.
ITV presenter Lorraine Kelly also just complained about the same issue.
The star, 60, replied to another Twitter user's post of another messy park scene.
The original user tweeted: "6am, Lorraine..."
To which Lorraine replied, in view of her some 609,700 Twitter followers: "Ridiculous - so selfish - drives me nuts."
Other Twitter users have vented their anger over littered public spaces in recent days.
"We are creating a pandemic"
Many beachgoers have noticed extensive rubbish build-ups on the beaches.
Beach clean-ups have even been organised - despite the heatwave only lasting a few days.
One irritated Twitter user tweeted: "12 tonnes of rubbish left on Bournemouth beach yesterday. People had even defecated in burger boxes & left on beach. We are creating a pandemic & pollution hell on Earth #Covid19UK #plasticpollution."
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