The Big Jubilee Lunch’s organizers warned Britons Monday to get their garages ready as a backup site in case Sunday’s event is rained out.
As the Queen’s Platinum Jubilee approaches, much of the UK is expecting milder weather, but rains threaten to damper the festivities in certain parts.
While many of the millions attending more than 200,000 special dinners expect sunny skies on Sunday, rain is anticipated for London and the south east.
Lindsey Brummitt, Programme Director at Eden Project Communities, organisers of The Big Lunch, suggested it was best to prepare for any eventuality.
‘While sunshine isn’t guaranteed, we know that a bit of rain won’t dampen British people’s passion for street parties and community get-togethers!’ she told MailOnline.
‘Luckily, it’s not too difficult to weatherproof a street party and adapt to the elements – we’d recommend gathering in the garage, bringing out the brollies or even taking the celebrations indoors if needed. Rain or shine, it’s set to be a corker!’
However rain is likely to put some plans in danger in western Scotland and Northern Ireland.
Saturday looks dry, with temperatures in the low 20s and spells of sunshine for much of the country as an area of high pressure moves in.
However, there is a risk of some heavy showers to areas ‘south of the M4’ in England, Mr Claydon said, threatening the Epsom Derby and later the BBC’s Party at the Palace open-air concert.
Sunday promises to be dry and bright for many of the millions gathering at more than 200,000 special lunches due to be held that day.
There is still a possibility that people might need their umbrellas, with a chance that the warm air edges back into the south east and brings rain to the Jubilee Pageant parade through the streets of London.
‘If you were to look at the northern portion of the UK, it’s a fairly decent long weekend, but the uncertainty and the chance of heavy showers in the south is still up for grabs,’ Mr Claydon said.
The Met Office urged Britons heading outdoors to pack sunglasses and sun cream, as UV levels will be high when the June sun does appear.
‘For the four days there’ll be a lot of dry weather around. Yes, still some showers here and there… but many places will see sunny spells and certainly after a cool start this week it is going to be feeling warmer,’ Met Office meteorologist Alex Deakin said.
It comes as hardcore royal fans who have camped out days ahead of the Platinum Jubilee laughed off torrential downpours which they said were “worth it” to be part of the celebrations.
Rain failed to dampen the spirits of those for whom a handful of tents along the side of The Mall in central London will be home this week.
The royalists secured their spots early near Buckingham Palace in the hope they will get the best view of the Queen and her family.
Pat Hart, 46, and his wife Angie, 51, travelled to the capital on Saturday with their two daughters, from near Toronto in Canada.
Mrs Hart is on her third trip for a big royal event, having camped out for the weddings of the Cambridges and the Sussexes.
She described camping out as “lots of fun”, adding: “Brits know how to do pomp.”
They will spend their first night camping on Tuesday and stay in position until after Trooping the Colour on Thursday.
Speaking after a downpour, Mrs Hart said: “We had some lovely British hail, and wind and rain but it’s worth it. By the end of it it’s always worth it and I think the harder it is maybe the more rewarding it is.”
Laughing, she added: “I’ll keep telling myself that anyway.”
Explaining why she wanted to travel to the UK and camp out to see the royals, she said: “I love the rich history. My grandmother was British and she taught me about England and Britain and the royal family.
“I have real respect and love for the Queen who has worked so tirelessly hard her whole life. And it’s the jubilee year and, honestly, the British know how to do ceremonial, the pomp and the pageantry, like nobody else. It’s pretty special.”
She described seeing the Queen as “the bucket list”, adding: “That’s why we’re camping out.”
Mrs Hart said they are “hoping and praying she’s up to it physically”.
The Queen has limited the Platinum Jubilee Trooping the Colour balcony appearance to working members of her family who carry out official public duties.
Eighteen royals will appear on Thursday including the monarch, if mobility problems allow, the Prince of Wales, the Duchess of Cornwall and the Duke and Duchess of Cambridge.
The Duke and Duchess of Sussex are returning to the UK for the jubilee but will not be on the balcony on Thursday.
Another royal fan and camper, Mary-Jane Willows, said she is hoping to spot Harry at some stage, having “missed him” since his move to the US.
The 69-year-old, from Penzance in Cornwall, a retired chief executive of a children’s charity, said: “I think we’ve missed him, personally. I think I’m pleased he did what he did for his own mental health but I’ll be thrilled to see him back here.”