(WVEC) -- What better way to cool off on a hot day than with a free iced coffee? That is the question Duck Donuts is asking.

The doughnut shop will be giving away free iced coffee all day on Wednesday, June 21.

"The first day of summer is a much anticipated day for adults and children and what better way to celebrate than with a refreshing iced coffee paired with vacation-inspired, warm, delicious and made-to-order donuts," said Russ DiGilio, founder and owner of Duck Donuts Franchising Company LLC. "The summer solstice is the longest day of the year and Duck Donuts is excited to help its customers stay energized throughout the day with a free, 16-ounce iced coffee."

Customers will get the choice of Southern Pecan flavor or the Duck Donuts signature coffee, Light House Blend.

Customers must have a coupon in order to redeem the free drink, which is available on the Duck Donuts website.

Customers must show the coupon to the cashier either using their mobile phone or a print out. There is a limit of one regular sized iced coffee per person.

This offer is available at all participating locations.