The recommendation lists below includes titles/authors at somewhat varied reading levels. Parents/students are encouraged, however, to look at the lists for the grade levels above and below the target grade.
For more recommendations, see School Library Journal's Summer Reading 2021. They did not make a 2022 version but this one still has some great recommendations.
Non-Fiction Series/Authors
Dead Famous (biographies)
Eyewitness – Dorling Kindserley
Horrible Histories
How They Croaked / Choked – Georgia Bragg
Thrifty Guide to ... (history) – Jonathan Stokes
Recommended Series
Magisterium – Holly Black
Sisters Grimm – Michael Buckley
Allie Finkle's Rules for Girls – Meg Cabot
City of Ember – Jeanne Du Prau
Ranger's Apprentice / Brotherband Chronicles – John Flanagan
Joey Pizga – Jack Gantos
Warriors/Survivors/Bravelands – Erin Hunter
Hatchet (& sequels) – Gary Paulsen
Treasure Hunters – James Patterson
Shadow Children – Margaret Peterson Haddix
The Olympian series – Rick Riordan
Inkheart – Cornelia Funke
Septimus Heap - Angie Sage
Wings of Fire – Tui Sutherland
Sammy Keyes – Van Draanen
39 Clues – Various Authors
Authors
Sharon Creech
Russell Freedman
Stuart Gibbs
Morris Gleitzman
Dan Gutman
Kevin Henkes (novels)
Carl Hiaasen
Gordon Korman
Wendy Mass
Michael Morpugo
Linda Sue Park
Gary Paulsen
Seymour Simon
Jerry Spinelli