Pisces tend to absorb the emotions and vibrations of the people around them, and it can be hard to wind down after a long day of doing so. “These are complex, sensitive people who need to cut themselves off from the world in the evenings,” says Ms. Charlotte. “In order to clean out their system of energetic pollution, they stay up until the wee hours of the morning making art, casting spells, or doing manifestation rituals.”

Ms. Charlotte describes Scorpios as the sign that governs the “nighttime of the year,” aka the end of summer, so it’s no surprise to see the water sign on this list. According to Ms. Charlotte, Scorpios feel “most alive when everything is quiet and dark,” and spend their time “investigating, researching, and perhaps even stalking until the wee hours of the morning.” If you know a Scorpio, you’re probably all too familiar with these late-night antics.

“The evenings give Scorpios time to unwind and process all the information they've gathered throughout the day,” says Ms. Charlotte. “The nighttime is the only time the suit of armor can be removed so they can let loose and enjoy their own company.”

Sagittarius closes out this list as the fire sign that struggles with sleep the most. Sagittarians are natural-born explorers who are “always looking for the next adventure,” and because of this, it’s not uncommon for the sign to prioritize experiences over their sleep. “They might want to stargaze in the wilderness or take a long drive to the beach if they fancy,” says Ms. Charlotte. Though they’re thrill-seeking free spirits, Sagittarians have also been known to appreciate a deep chat about life — and will talk into the early hours of the morning if you let them.