The Olympic Park in east London has come under criticism for the lack of shelter available to visitors.
Angry ticket-holders to the Stratford venue have spoken out about their frustration at the lack of shaded areas during hot weather and the dearth of covered space when it rains.
The criticism comes as temperatures are expected to creep up into the mid-20s this week and sports fans attending events at the weekend are also warned to prepare for thundery showers.
Deluges last weekend saw crowds flock to the only two places of shelter inside the park - the official London 2012 merchandise store and the 1,500 seat capacity McDonald’s - both of which resulted in large queues and visitors forced to take cover under bridges.
Nicola Foster-Ward, who went to the park to watch the basketball on Sunday, said: "Olympic volunteers had ponchos for protection but there was nothing for spectators.
"The only place to go to hide from the rain was the official shop and McDonalds but both were so busy that people were queuing for hours."
When Sky News weather presenter Isobel Lang visited the Aquatics Centre, inside the Olympic Park, she said the lack of shelter from the rain was noticeable even on a dry evening.
She added: "I was lucky to have fine weather at the Olympic Park on Monday, if fairly breezy. However, if the forecast is for rain, I would take an umbrella and a mac as there doesn't seem to be anywhere to shelter."
With sunshine and showers a matter of course during the British summer, others have taken to Twitter to vent their anger.
One called Anthony Davis wrote: "The heavens opened and with nowhere to shelter in the #OlympicPark it was time to head for the exit."
Another, writing as chrisspyrou, said: "I'd avoid McDonalds in the Olympic Park, but... the side entrance is proving to be an excellent shelter from the rain."
Laura Snoad added: "Biggest criticism of the Olympic park: not enough covered spaces. Not on people having to shelter under the bridges."
A sports fan writing as crumbsfordinner said: "Major flaw at Olympic park: told to get here far too early. Nowhere to shelter in event of torrential rain #soaked."
A blogger called Diamond Geezer has even come up with a list of "places to hide when it rains" inside the park.
Hot and sunny weather has also caused problems, with parents voicing their concern on the popular web forum Mumsnet.
Under London 2012 rules, visitors are only allowed to bring in up to 200ml of sun cream into the park and it "must be in its original packaging and in a container with a maximum capacity of 200ml".
One mother, named ImaginateMum, posted: "Yes, you can take sun cream up to 200 ml. It was more that people got taken by suprise and had bigger bottles. It was a very hot and sunny day.
"I am from down under and at an event as sunny as that, they would usually have a cancer charity with free sun cream available - and that is when they haven't taken it off you at the door!"
Use of oversized hats and large golf-style umbrellas to protect against the elements are also restricted inside venues.
Official advice to visitors on the Games websites says: "The Stadium is an open-air venue, so please check the weather forecast and come prepared."
A Locog spokeswoman told Sky News: "There are many places where people visiting the Olympic Park can sit and relax, for example, cafes.
"A lot of our venues are also indoors. We advise those visiting the Park to check the weather forecast and plan accordingly."