Ashlee Simpson celebrated her 30th birthday on Friday evening, and while Southern California is experiencing a bit of a heat wave, the starlet had a winter-themed bash with family and friends!

Ash's hubby Evan Ross posted the pic above and wrote, "Last night made it @ashleesimpsonofficial favorite holiday Christmas in California. It was a snowy one. Happy birthday baby."

Jessica Simpson posted a glam throwback shot of her sister on Instagram and wrote, "Happy Birthday Ashlee! There is no one I believe in more than you. Thank you for inspiring me everyday. I love you!!! #dirty30," along with the above shot, which she captioned, "Ready to celebrate 30yrs of having the best sister on the planet! Happy Birthday @ashleesimpsonofficial."