Decathlon MT500 60 L Hiking Rain Poncho

Skip the single-use plastic ponchos that end the weekend as litter. This one has long sleeves, so you can hold a drink or a phone without water running down your arms, and it is cut to cover a backpack of up to 60 L, which makes it just as useful on the rainy trudge from the parking lot as in front of the main stage. A 2,000 mm coating and fully taped seams keep a real downpour out. It costs a fraction of a good rain jacket. The trade-off is breathability: there is no breathable membrane, so you will get clammy if you dance in it, but you can throw it on in seconds when a shower rolls in.