What reading level is Horrible Harry and the secret treasure?

Horrible Harry and the secret treasure by Suzy Kline is at a Level 3-4 reading level (Lexile 510L). Recommended for Lower Grades readers (Ages 5-8).

What age is Horrible Harry and the secret treasure appropriate for?

Horrible Harry and the secret treasure is recommended for Ages 5-8. HootRating: 8C (Clear).

What genre is Horrible Harry and the secret treasure?

Horrible Harry and the secret treasure is fiction. Part of the Horrible Harry series.

Does Horrible Harry and the secret treasure have any content warnings?

Horrible Harry and the secret treasure has a HootRating of 8C (Clear). No specific content flags noted. On HootRated, every book is rated across four dimensions — emotional, physical, social, and thematic — to help parents make informed choices.

Reviewed by HootRated editorial · Last updated May 18, 2026

Horrible Harry and the secret treasure

Suzy Kline

Horrible Harry and the secret treasure

Age Rating, Reading Level & Content Guide

by Suzy Kline

Horrible Harry

Reading Level 3-4 8C Ages 5-8 Balanced Read

The text is written at a 3rd grade reading level, the subject matter is intended for younger children (ages 5–8), and the content is gentle with no concerning themes.

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About This Book

Harry comes up with a clever plan to make up with Mary and invites all his friends to join an exciting detective adventure filled with surprises and prizes. Together, they solve clues and share lots of fun along the way. It's a story about friendship, teamwork, and making things right.

Themes

Friendship AdventureTeamwork

Quick Assessment

This is a Level 3-4 book with gentle content intensity. No notable content concerns flagged. Written for readers ages 5-8.

Why we rated Horrible Harry and the secret treasure 8C

Horrible Harry and the secret treasure is written at a Level 3-4 reading level with a Lexile measure of 510L (approximately 5,953 words). Strong independent readers around grade 4.5 can typically handle this book on their own; with parent or teacher support, Horrible Harry and the secret treasure works for readers up to grade 5.5.

Read aloud, Horrible Harry and the secret treasure takes about 40 minutes, which fits within a single read-aloud session.

We rate Horrible Harry and the secret treasure as 8C ("Clear") because the content sits in the "Gentle" range — no conflict beyond everyday childhood experiences. Across our four dimensions (emotional, physical, social, thematic) the book reads as evenly gentle; no single dimension stands out as a concern.

No specific content flags were raised by community reviewers, which is consistent with the gentle intensity score.

Thematically, Horrible Harry and the secret treasure explores friendship, adventure, and teamwork — these threads give the book room to mean different things to different readers.

Good fit for

✓ Children in the Ages 5-8 range — the maturity and attention span match the story's pacing.
✓ Readers who like a steady plot with enough momentum to keep pages turning.
✓ Kids drawn to stories about friendship, adventure, teamwork.
✓ Readers who fall hard for one book and want a long series to live in — there are 17 more books in the Horrible Harry series.