Say goodbye to spring and hello to summer because beautiful sunny weather has officially arrived! Check out how your favorite celebs celebrated the change of season below in our favorite Instagram pics of the week!

Usher posted this fun behind-the-scenes photo Monday with his Voice co-stars Blake Shelton and Shakira.

Joe Jonas enjoyed a boys night at Yankee Stadium with his brother Kevin on Tuesday.

Ryan Seacrest shared this cool pic Wednesday with the caption, "Which side will you land on? #idol."

Bar Refaeli made our week with this adorable #ThrowbackThursday shot. How cute was she?

Hilary Duff took baby Luca for a stroll on Friday in the most precious outfit we've ever seen!

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What was your favorite celeb photo this week? Let us know @OKMagazine and in the comment section below. Also, don't forget to follow us on Instagram!

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