Castle Episode Ratings Heatmap
2009 · 8 Seasons · 173 Episodes · Overall Score: 7.4/10 (173 rated)
Season 4 holds the highest collective average score across the series.
Season 4 Details →Lowest score variance (σ = 0.24), maintaining an average of 7.3.
Complete Episode Rating Matrix
Interactive score chart by season and episode number. Darker green indicates higher ratings; amber and red denote lower reception.
| Episode | Season 1 | Season 2 | Season 3 | Season 4 | Season 5 | Season 6 | Season 7 | Season 8 |
|---|---|---|---|---|---|---|---|---|
| Ep 1 | 7.5 | 7.3 | 7.9 | 7.7 | 8.1 | 7.7 | 6.9 | 7.5 |
| Ep 2 | 7.4 | 7.5 | 7.6 | 8.3 | 7.0 | 7.4 | 7.2 | 6.7 |
| Ep 3 | 7.1 | 7.0 | 7.7 | 7.6 | 7.7 | 7.5 | 7.0 | 6.4 |
| Ep 4 | 7.2 | 7.7 | 7.9 | 7.6 | 7.1 | 7.7 | 6.9 | 7.1 |
| Ep 5 | 7.3 | 7.4 | 7.8 | 7.5 | 8.3 | 7.4 | 6.8 | 7.6 |
| Ep 6 | 6.7 | 7.5 | 8.0 | 7.9 | 8.1 | 6.9 | 7.5 | 7.5 |
| Ep 7 | 7.3 | 7.3 | 6.9 | 7.9 | 7.4 | 7.8 | 7.1 | 7.4 |
| Ep 8 | 7.4 | 7.5 | 7.5 | 7.2 | 7.7 | 7.2 | 6.8 | 6.4 |
| Ep 9 | 7.3 | 7.2 | 7.9 | 7.8 | 7.8 | 7.2 | 7.3 | 7.1 |
| Ep 10 | 7.5 | 7.5 | 7.8 | 8.1 | 7.3 | 7.3 | 6.7 | 6.3 |
| Ep 11 | – | 7.8 | 7.4 | 7.1 | 7.3 | 7.5 | 8.1 | 6.6 |
| Ep 12 | – | 7.1 | 7.0 | 7.2 | 7.4 | 7.6 | 7.3 | 7.2 |
| Ep 13 | – | 8.1 | 8.3 | 7.6 | 7.9 | 7.0 | 7.4 | 7.2 |
| Ep 14 | – | 7.6 | 7.6 | 7.9 | 6.9 | 7.2 | 7.7 | 6.5 |
| Ep 15 | – | 7.4 | 7.0 | 8.0 | 8.0 | 7.8 | 7.6 | 7.4 |
| Ep 16 | – | 7.2 | 8.0 | 7.9 | 7.8 | 7.6 | 6.8 | 7.3 |
| Ep 17 | – | 8.3 | 8.2 | 7.6 | 7.7 | 8.0 | 7.2 | 7.1 |
| Ep 18 | – | 8.1 | 7.6 | 6.5 | 7.7 | 7.8 | 6.4 | 7.3 |
| Ep 19 | – | 7.3 | 7.5 | 8.3 | 7.5 | 7.4 | 7.2 | 7.5 |
| Ep 20 | – | 7.3 | 7.5 | 7.6 | 7.4 | 7.4 | 7.1 | 7.1 |
| Ep 21 | – | 7.5 | 7.7 | 8.1 | 7.3 | 7.3 | 6.6 | 7.4 |
| Ep 22 | – | 6.9 | 7.9 | 7.0 | 7.5 | 8.1 | 6.9 | 6.8 |
| Ep 23 | – | 7.1 | 6.8 | 8.3 | 6.7 | 6.1 | 7.6 | – |
| Ep 24 | – | 7.7 | 8.4 | – | 7.4 | – | – | – |
| Season Avg | 7.3 | 7.5 | 7.7 | 7.7 | 7.5 | 7.4 | 7.1 | 7.1 |
Ratings Analysis & Trajectory
Across 8 seasons and 173 episodes, Castle has earned an overall series rating of 7.4 out of 10. The series displays remarkable consistency across its narrative arc, maintaining reliable ratings from premiere to conclusion.
The single highest-rated hour of television in the series is Season 3, Episode 24 ("Knockout"), rated at an extraordinary 8.4/10 with 21 ratings. Conversely, the lowest-rated installment is Season 6, Episode 23 ("For Better or Worse"), landing at 6.1/10.
The most precipitous single-episode shift occurred in Season 6 between Episode 22 ("Veritas", 8.1) and Episode 23 ("For Better or Worse", 6.1), a swing of 2 points.
Top 10 Highest Rated Episodes of Castle
| Rank | Episode | Title | Score | Votes | Air Date |
|---|---|---|---|---|---|
| #1 | Season 3, Ep 24 | Knockout | 8.4 | 21 | May 16, 2011 |
| #2 | Season 2, Ep 17 | Tick, Tick, Tick... (1) | 8.3 | 27 | Mar 22, 2010 |
| #3 | Season 4, Ep 2 | Heroes & Villains | 8.3 | 23 | Sep 26, 2011 |
| #4 | Season 3, Ep 13 | Knockdown | 8.3 | 20 | Jan 24, 2011 |
| #5 | Season 4, Ep 19 | 47 Seconds | 8.3 | 19 | Mar 26, 2012 |
| #6 | Season 4, Ep 23 | Always | 8.3 | 18 | May 7, 2012 |
| #7 | Season 5, Ep 5 | Probable Cause | 8.3 | 18 | Oct 29, 2012 |
| #8 | Season 3, Ep 17 | Countdown (2) | 8.2 | 23 | Feb 28, 2011 |
| #9 | Season 2, Ep 13 | Sucker Punch | 8.1 | 27 | Jan 18, 2010 |
| #10 | Season 2, Ep 18 | Boom! (2) | 8.1 | 27 | Mar 29, 2010 |