Nicole Altamirano, above, helps her mother, Mattie Washburn Elementary School teacher Cynthia Altamirano, set up her “Whale of a Classroom” theme Tuesday in preparation for today’s start of school in the Windsor Unified School District.

Healdsburg Unified School District will follow Windsor, starting its school year Thursday.

The two districts, which combined have around 7,100 students, are ahead of the back-to-school wave that will hit next week, particularly next Tuesday and Wednesday.

That’s when about three-quarters of the county’s 40 school districts will start instruction.

However, Windsor isn’t the first district back: Bellevue Union in Santa Rosa, with about 1,800 kids, started Aug. 6.