We had a 24'X 30' space dug up and lined then sand brought in for my child care center, the kids loved it. They had their climbing equipment in that area and we kept the fall zone clear of toys, they had buckets, shovels, everything possible, and we just had to make sure we checked it for cat pooh, and things that can blow in like trash before letting the kids go outside. Sand is easy to get off and vacuum up, the kids just have to make sure they take off their shoes and shake the sand out before entering the building.
I had several staff and could spare the time for one of them to walk the playground before hand each time. If you are alone then the only way I would do it is with a tight fitting cover that won't blow off.
The kids are required to go outside every day according to my state reg's. But we don't go outside if it's below 50 or stormy. An option you might want to consider is a type of sensory box. We had one a LaPetite when I worked there. It was a large wooden box on wheels and it had a good sturdy cover. The kids could sit in their chairs and play with it sitting. It had pasta, rice, beans, measuring cups, cars, etc...so many different things. The kids got to experience many textures and they would just sit and play for hours if allowed.
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Just an idea, for St. Patricks Day I had a largish tub (almost big enough to hold a 5-10 gallon fish tank)and I filled it with green Easter grass, the paper kind not that clingy nylon/plastic stuff, I hid lots of little things in it like hot wheels, blocks, I had a list beside the box on the wall and the kids each got a turn to find the items, the items went back in after the child was done and I stirred it back up so they were all around inside it. When it got to be St.Patricks Day I put candy coins in it too along with the other items and let the kids keep a coin when they found it. I bought them at the Dollar Tree or Dollar Store, where everythings a dollar or less.