Elementary classrooms were bursting Tuesday as Palo Alto students showed up for the first day of the 2010-2011 school year.
"Elementary-level enrollment is up -- we don't know how much yet, but it's fairly dramatic," Superintendent Kevin Skelly told the Board of Education Tuesday night.
Middle school enrollment showed a "slight increase," while high school enrollment was down.
Skelly said elementary enrollment may even "exceed the high projections we had at the beginning of the year," while middle and high-school enrollment will fall beneath the low-end projections.
Official enrollment figures are not calculated until early September.
The bumper crop of little ones means some K-3 class sizes will be at 22 -- and in some cases 23, he said.
Classes went to 23 "when we got to the position that we didn't have any more seats. In general, (K-3) classes are very close to 22," Skelly said.
Fourth- and fifth-grade class sizes are between 20 and 24, he said.
Last year's official district-wide enrollment, taken on the 11th day of school, was 11,680, up 249 from the previous year.
To accommodate projected growth, the district in 2008 and 2009 developed plans to re-open Garland School at 870 North California Ave. as a thirteenth elementary campus.
The school board retreated from that plan a year ago, citing financial uncertainties. The Garland site currently is under lease to Stratford School, an independent pre-K through 5 school.