Want more summer fashion, shopper-approved buys and the hottest trends? Sign up for Yahoo Lifestyle Canadas newsletter!Save 40% on select swimwear with Old Navy's one-day sale.Yahoo Lifestyle Canada is committed to finding you the best products at the best prices. We may receive a share from purchases made via links on this page. Pricing and availability are subject to change.Temperatures are rising and that means its time to embrace the summer season with beach days, pool hangs, and everything in between.If you're looking to stock up on swimwear, Old Navy's one-day flash sale is the perfect place to start. Today only, the already-affordable retailer is currently offering 40 per cent off select swimwear for the whole family.Click here to sign up for Yahoo Canada's lifestyle newsletter.For women, youll find a whole range of bikinis, one-piece swimsuits, and mix-and-match styles that will have you geared up for summer in a flash. Mens styles include practically endless colours and patterns of swim trunks and board shorts, along with sun-safe rash guards too.Since the clock is already ticking on this limited-time deal (it ends tonight at midnight!), youll want to take advantage of these top savings while you can. Shop some of our top picks below before this deal is over. High-Waisted Textured-Rib Drawstring Swim Bottoms. Image via Old Navy.For those who like a little more coverage, these high-waisted swim bottoms offer the perfect balance between style and function.SHOP IT: Old Navy, $24 (originally $40)Printed Swim Trunks 8-inch. Image via Old Navy.Nothing says summer like a tropical print, and these swim trunks are ideal for your next beach day.SHOP IT: Old Navy, $21 (originally $35)Textured-Rib High-Cut One-Piece Swimsuit. Image via Old Navy.A simple yet sultry silhouette makes this one-piece swimsuit a must-have of the season.SHOP IT: Old Navy, $33 (originally $55)Graphic Long-Sleeve Rashguard Swim Tee. Image via Old Navy.Stay safe while enjoying the sun in this long-sleeve rashguard that offers built-in UPF 40 sun protection and a quick-drying finish.SHOP IT: Old Navy, $21 (originally $35)Printed Bralette Swim Top. Image via Old Navy.Inspired by your favourite loungewear bralette, this printed bikini top has a comfortable and supportive fit.SHOP IT: Old Navy, $33 (originally $55)Printed Built-In Flex Dolphin-Hem Board Shorts 10-inch. Image via Old Navy.These board shorts feature a retro-inspired design with an all-over print and a contrasting curved hem.SHOP IT: Old Navy, $24 (originally $40)Textured-Rib V-Neck Tie-Waist One-Piece Swimsuit. Image via Old Navy.This swimsuit brings a vibrant pop of colour to your warm weather wardrobe.SHOP IT: Old Navy, $33 (originally $55)Solid-Color Dolphin-Hem Board Shorts 10-inch. Image via Old Navy.Whether youre in or out of the water, these versatile board shorts are ready to take on the day.SHOP IT: Old Navy, $20 (originally $33)Textured-Pique O-Ring Swim Top. Image via Old Navy.This classic bikini top has been updated for the season with a textured finish and a fun ring detail at the bust.SHOP IT: Old Navy, $21 (originally $35)Let us know what you think by commenting below and tweeting @YahooStyleCA! Follow us on Twitter and Instagram and sign up for our newsletter.