Are they named, so you have x number of clumps that cannot be mixed with any other clump? Did you dig them in clumps with some dirt still on each clump, or clean them off as you dug them?

Are they a variety of colors and you just have a pile of iris rhiz?

Get yourself a clothes basket or two from the dollar store,
pile them in the baskets wily nily, set the baskets on a slant under a shade tree so the rain won't sit in the bottom and rot any of them, and hold them there until you replant.

If they are named, and you have several clumps, write the names on the mid-most fan piece of each one, and put them
on the ground around the trunk of a shade tree until you can replant them. If you have an old mini blind, pull it apart, cut the plastic pieces in 6" sections, and stick a couple of sections with the color/name on them in the middle of each clump. If weathered as normal, they will be dry and go dormant, but the name will survive on the mini blind section.

I would clean them and store them in a cardboard box inside where it isn't so hot or humid. I would also take them out of the box about once a week to give them a water spritz and allow them to dry completely off before returning them to the box again.