Quick Answer

In the CW’s Supergirl TV series, Krypton’s destruction is said to have happened 24 years before the start of Season 1 (which aired in 2015), placing the event roughly around 1991 in the show’s internal timeline.

How the Show Establishes the Timeline

Opening Monologue Clue

  • In the pilot episode, Kara Zor-El narrates:

“24 years ago, my planet, Krypton, was in serious peril…”
This line is repeated in later episodes and promotional material, establishing the “24 years ago” marker as the show’s canonical reference point for Krypton’s end.

Why Fans Spot a “Plot Hole”

  • The intro also shows Kara as a 13-year-old when Krypton explodes, then sleeping in the Phantom Zone “for those 24 years,” yet arriving on Earth still appearing 13, while the story’s “present day” has her as a mid-20s adult.
  • Fans on Reddit and IMDb note this creates a timeline mismatch: if Krypton blew up 24 years ago and she was 13, then the “present” should make her ~37 unless additional time passes after she arrives on Earth. Many conclude the writers likely meant ~36 years total, but kept the “24 years” line for dramatic effect.

A Common Fan-Reconstructed Timeline

Based on dialogue and fan analysis, a widely cited rough timeline for the show looks like this:

  • ~1965 – Kara Zor-El is born on Krypton
  • ~1978 – Krypton is destroyed; Kal-El (Superman) is born around this time in show lore
  • ~2000 – Superman first appears publicly in Metropolis
  • ~2003 – Kara arrives on Earth after Phantom Zone stasis
  • ~2015 – Season 1 begins; Kara is about 24–25 and becomes Supergirl

This reconstruction effectively treats the “24 years” line as referring to the time between Krypton’s destruction and Kara’s arrival on Earth, with another ~12 years passing before the main story kicks in.

Key Takeaways

  • Canonical statement in-show: Krypton was destroyed 24 years before Season 1.
  • Practical timeline implication: To make Kara’s age work, the full span from Krypton’s explosion to Season 1 is closer to 36 years , with ~24 years in the Phantom Zone + ~12 years on Earth before she becomes Supergirl.
  • On-screen year reference: Since Season 1 aired in 2015 and is set roughly in the same year, Krypton’s destruction falls around 1991 in the series’ internal dating if you take “24 years before 2015” literally.

TL;DR: The show explicitly says Krypton was destroyed 24 years before Season 1 , but to reconcile Kara’s age, fans and analyses treat the total timespan as closer to 36 years , putting the catastrophe roughly in the early 1990s in the show’s timeline.

Information gathered from public forums or data available on the internet and portrayed here.