How to protect a washing machine from weather?

The best "hack" I imagine is to bring a water connection and drainage indoors (where you already have electricity). It should be easier and safer, from all points of view.

Installing the machine outdoors has more than the problems you mentioned (rain and heat). Dust, moist in the air (rain not needed), fog. The greatest danger actually occurs in the winter: freezing. Not only that you cannot use the machine, the insides being blocked by the ice, but the ice will actually physically break the insides of the machine (especially tubes / pipes).

---

I can't differentiate between iron and steel

It cannot be iron, so it is steel - especially that washing machines are not made of cast iron.

Place the machine on a pallet and cover it with a barbecue large cover or a large mower cover. Keep it off the ground and that will let you get more years and use out of it. Good luck.

Shopping bags usually have ventilation holes so they are not very waterproof. Plastic sheeting might do, but will soon develop splits and tears. If you can't find a servicable tarpaulin (perhaps one that is no longer useful on a truck), I suggest a way to move the washing machine.

---

My hack to move a washing machine or a cooker easily and simply, is to use a blanket as a sling. The two people carrying it go one each end so it is easy to get through doorways, without skinning your knuckles.

Lay the blanket on the floor. One person tips the machine from side to side so that the other person can work the blanket underneath, to get the machine in the middle of the blanket (side to side) but a bit nearer one end than the other, so that when it is tipped over backwards (next para) it will be central.

Then one person winds a corner of the blanket around each hand. The other person tips the machine back towards the first person, so it is supported by them, and by the blanket trapped underneath one edge. Then the second person winds the other corners of the blanket around each hand, and you are ready to go.

Moreover it is kinder on the hands, because you are not holding the sharp and uncomfortable metal edges of the machine.

I suggest a Hack for easier moving as an alternate to a light-weight washing machine cover.

Consider moving your heavy washing machine a lot more easily [if a little slower] from storage to the washing space using rollers rather than the bad tyres.

You need two planks for either side of a "skid" to make a flat bottom surface.
and
You need four or five lengths of PVC drain pipe to make "rollers" instead of your tyres.

• Place your washing machine on the skid with two legs on each of the two planks.
  
• Fasten the washing machine to the skid securely as this will be the new support for your washer. You may want to remove the old tyres when you do this.
  
• Lift the skid containing the washing machine onto the rollers. Alone, you can lift one plank at a time to place the rollers under the skid using a lever or with help.
  
• After the washer is sitting on the rollers, one person can push the load stopping periodically to replace the "free" roller from the back to the front as you continue toward your washing space or vise-versa returning to your shelter from the weather. The washer will be much easier to roll instead of carrying.
  TIP: You might even find it is easier control your direction by pulling instead of pushing your load.
• When you get to the washing area, leave the washing machine on the skid. You do not have to load or unload it again until you have found a suitable permanent arrangement.

This is the way great stones for the pyramids and also quarry stones for Stone Henge in England were moved (I'm told).

Here's an illustration of very early work on one of the pyramids in Giza. Larger rollers and closer spacing make rolling easier over the ground.

Good luck.