styrofoam coolers
 

Going to Iceland in mid June. Are Styrofoam coolers available in stores in Reykjavik.

I can't answer your question but can advise that they may be called something else. When we arrived in New Zealand we asked for a styrofoam cooler and, after much discussion, we found that we really wanted a polystyrene chilly bin! Armed with that information, we asked for a polystyrene chilly bin when we got to Australia, only to discover that we actually wanted an "Eskie" (short for Eskimo which is a brand name there). Amazing that we all spoke English!!!

BTW, I should have mentioned that we got them free in grocery stores because their produce from off shore is packaged in them.

Sorry, I can't help, either, but I did get a chuckle thinking that anyone would ever need a cooler of any kind in Iceland, no matter what time of year.

When traveling, we take a soft sided cooler that folds flat. Some people use the cooler bags sold in the US in grocery stores for not much money.
Even if the temp is only 60, we prefer perishables, like dairy products, to be in a cooler with ice packs.