If you’ve spent any time on TikTok or scrolled through Cousins Beach fan edits lately, you know the vibes. Everyone is obsessed with the Fisher brothers. But between the glowing tan lines and the messy love triangle, things get a little hazy regarding the actual calendar. Specifically, people keep asking: what age is Jeremiah in The Summer I Turned Pretty? It’s not just a trivia question for the superfans. Knowing exactly how old Jere is changes how you view his decisions, especially when he starts acting way more mature—or way more impulsive—than his older brother, Conrad.
Jeremiah Fisher is the quintessential "golden boy" of the series. He’s the life of the party, the one with the easy smile, and usually the guy holding a Solo cup. But beneath that "sunshine" persona, there’s a specific age gap that dictates everything about his relationship with Belly and Conrad.
The Cousins Beach Timeline: Jeremiah’s Age in Season 1
In the first season of the show (and the first book by Jenny Han), Jeremiah is 16 years old.
He’s just a bit older than Belly, who starts the series at 15. This tiny age gap is actually why they’ve always been best friends. While Conrad was off being the "brooding older brother" at 18, Jeremiah and Belly were stuck in that middle-ground of childhood. They were the ones playing tag while Conrad was probably staring at the ocean thinking about complex physics or whatever he does.
Jeremiah being 16 in Season 1 is crucial. It’s that sweet spot of high school where you’re old enough to have a summer job and a car, but young enough to still feel like a kid. He’s a junior in high school during that first summer we see on screen. It explains his lightness. He hasn't quite hit the "real world" pressures that are already crushing Conrad, who is heading off to college.
Growing Up Fast: Jeremiah in Season 2 and Beyond
By the time we hit the emotional rollercoaster of Season 2, which covers the events of It’s Not Summer Without You, Jeremiah has turned 17.
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He’s now a senior in high school. This is a massive shift. The "golden boy" isn't just partying anymore; he's dealing with the devastating loss of his mother, Susannah, and trying to navigate a fractured relationship with his brother. Honestly, 17 is a brutal age to go through that. You're trying to figure out college applications while your entire world is falling apart.
When you look at what age is Jeremiah in The Summer I Turned Pretty during the second installment, you see a kid forced to grow up way too fast. He becomes the primary caretaker in many ways, staying home and dealing with the reality of his mom’s illness while Conrad is away at school. That jump from 16 to 17 represents the end of his innocence.
The Big Leap in Season 3 (Book 3)
Now, if the show follows the books for the upcoming Season 3, we are looking at a significant time jump. In the third book, We’ll Always Have Summer, the story picks up two years later.
Jeremiah is 19 years old.
He’s a sophomore in college. This is where things get messy. At 19, he’s technically an adult, but as anyone who has been 19 knows, you're still basically a child with a bank account. This age is where he makes his most controversial decisions—including the infamous spring break incident and the subsequent proposal to Belly.
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The dynamic shifts entirely here. He’s no longer the "little brother" in the same way. He’s trying to assert his adulthood. It’s a fascinating look at how a two-year jump changes the stakes of a relationship. When he was 17, a wedding was a crazy idea. At 19, in his mind, it’s a way to prove he’s man enough to take care of Belly.
Why the Age Gap Between Jeremiah and Conrad Matters
There is a two-year age difference between Jeremiah and Conrad.
- Jeremiah: 16 (S1), 17 (S2), 19 (S3/Book 3)
- Conrad: 18 (S1), 19 (S2), 21 (S3/Book 3)
This gap is the engine of the show's conflict. Conrad is always "the adult." He carries the weight of secrets and responsibilities because he feels he has to. Jeremiah, being two years younger, often feels overlooked or treated like a baby.
When Jeremiah is 17 and Conrad is 19, that two-year gap feels like a canyon. One is still in high school; the other is experiencing the freedom of university life. It fuels Jeremiah’s resentment because he feels he’s doing more "adult" work at home than Conrad is, despite being younger. It's a classic sibling rivalry exacerbated by the trauma of their mother's death.
The Actors vs. The Characters: A Real-World Comparison
It’s always funny to look at the "Hollywood age" versus the character age. Gavin Casalegno, who plays Jeremiah, was born in 1999.
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When Season 1 filmed, Gavin was already in his early 20s playing a 16-year-old. By the time Season 3 rolls around, he’ll be mid-20s playing a 19-year-old. This is pretty standard for teen dramas, but Gavin brings a certain puppy-dog energy that makes the 16-17 age range feel believable.
Compare this to Christopher Briney (Conrad), who is also in his late 20s. The show does a great job of using styling—flannels for Conrad to look older, bright tanks and messy hair for Jeremiah to look younger—to maintain that high school/college illusion.
Key Takeaways for Fans
If you're keeping a timeline for your fanfic or just trying to win an argument with your Team Conrad friends, keep these milestones in mind:
- Season 1: Jeremiah is 16. He’s a junior in high school. This is his "peak sunshine" era.
- Season 2: Jeremiah is 17. He’s a senior. He’s dealing with grief and the house crisis.
- Season 3 (Expected): Jeremiah will likely be 19. He’ll be a college student facing adult-sized consequences.
Understanding what age is Jeremiah in The Summer I Turned Pretty helps clarify why he acts the way he does. He’s a kid who had to stop being a kid much earlier than he expected. Whether you're Team Jere or Team Conrad, you have to admit that being the "younger" one comes with a specific kind of baggage that he’s still trying to unpack.
To stay ahead of the curve, re-watch the Season 2 finale and pay close attention to the way Jeremiah handles the college conversation with his father. It sets the stage for his 19-year-old self in the next chapter. Keeping track of the character ages is the only way to truly understand the emotional maturity—or lack thereof—in the upcoming episodes. Keep your eye on the graduation dates; they tell the real story.