In Iowa, the first Friday and Saturday (but not Sunday) of August is Iowa’s Annual Sales Tax Holiday. All clothing and footwear considered appropriate for everyday wear and selling for less than $100 will not be subject to sales tax. Some view this as a savings of 6% (or more if there is a local option sales tax also). The Iowa Department of Revenue has thought about all the ways to work around the $100 requirement, and has rules to prevent those tactics. For examples, a store cannot sell each shoe for $60 in order to qualify when the shoes are typically sold as a pair for $120.Similarly, you cannot average the price of two items purchased as part of a "Buy one get one free" sale to get below the $100 limit. If you are so inclined to read the rules and details, the Iowa Department of Revenue provides more information on its website.
Nationwide I found it interesting to see the map of which states have sales tax holidays. The states are for the most part grouped together and are mostly in the south. (Note the holidays are not all this weekend, each state sets its own dates).
I also found it interesting to see what each states includes in the tax-exemption. The majority of states focus on back-to-school items, some include computer and school supplies. States like Alabama, Louisiana, and Virginia also have a sales tax holiday in the spring for hurricane preparedness supplies.