Usually September signals the start of a new part of the year - the weather is changing, the kids are back in school, and we start to hunker down as the days get shorter and chillier. However, this September's K-Pop chart toppers seem to indicate that K-Pop fans aren't quite ready for summer to be over.

WINNER's "Empty," which graced the tops of charts for most of August, remained a favorite, and the other hit singles were fast-paced, fun jams that would make the perfect soundtrack for a trip to the beach or a summer road trip with friends.

Here are September's chart toppers, and a little more reason to cling on to the last days of summer:

WINNER, "Empty"

The heartbreaking ballad kept its leader position on the September charts. This video is perfect for two types of people: those who want to see close-ups of their favorite WINNER members looking heartbroken, and real estate nerds that want to explore the beautiful apartment featured in the first half of the video.

Park Bo Ram, "Beautiful"

Park Bo Ram's debut single mirrors the "Superstar K" competitor's journey. Through some great costume changes and acting, she shows us the hard work -- including strenuous workouts, lifestyle changes, and hours spent making music -- that she has put in to go from nervous reality show contestent to confident K-Pop chart topping artist.

SISTAR, "I Swear"

It's no wonder this fast-paced, carefree song is making an appearance atop the K-Pop charts. The uptempo beat is perfect for working out or jamming in the car with friends. And the video, which shows the girls driving in a convertible, playfully shopping, and showing off their dance moves on a pristine beach, is enough to make any K-Pop fan ditch work or school and get to an impromptu dance party with their friends.

Super Junior, "MAMACITA"

Super Junior's goal with this song was to make a hit that was more relatable to their Latin American fans, and judging by the response to this song, they have certainly succeeded. The song has the typical K-Pop peppiness and sound, but Super Junior has sprinkled in some flamenco-inspired dance moves and Spanish lyrics to speak to their fans a few continents away. Combine that with the modern-day Spaghetti Western-inspired costumes and some tight choreography, and it's no surprise that this has been a runaway hit for Super Junior. We're likely to see a lot more where this came from.

Which chart-topper was your favorite K-Pop song of September?  Let us know in the comments section below!