The New York State Education Department (NYSED) released enrollment data for the 2020-21 school year. Here are the numbers for Greenburgh's ten school districts (including Pocantico Hills, Valhalla and Tarrytown, which all lie partially or even mostly outside of Greenburgh). To compare enrollments more accurately, these are K-12 totals only (GC, Elmsford and Tarrytown all add PreK to their reported enrollment totals - the other 7 Greenburgh districts do not) as I've subtracted out PreK.
The enrollment numbers are reported by the school districts late in the calendar year and, for 2019-2020, were counted prior to the impact of COVID closures. The current year's numbers show nearly across the board decreases, totaling a 1.8% decrease in K-12 public school enrollment townwide since the previous year. The reasons for the decline likely vary. The north end school districts (Tarrytown, Elmsford, Valhalla, and especially GC) have experienced multi-year declines, several for four consecutive years or more. [The most dramatic decrease is in Greenburgh Central which has seen enrollment fall 12% since 2016-17.]. Decreases did accelerate in Tarrytown and Elmsford since last year.
The surprises come in the "prestige" school districts: (1) popular Ardsley, which has seen large enrollment increases in recent years, stalled with a small decline; (2) wealthy Edgemont and Irvington school districts also saw small drops after several years of steady increases, and (3) most dramatically, Hastings-on-Hudson experienced a shocking 4% enrollment decrease since last year, largest in the town.
Without internal data from the school districts, we can only speculate for the reason that public school enrollment has turned downward. In the north-end of the town, this is probably the continuation of existing trends with possibly some small COVID related impact. But for the elite districts that have seen years of steady increase until now? We know from the New York Times' reporting that that Hastings is a center of the learning pod movement that has emerged in response to COVID school closures. Are some well-to-do parents pulling their kids out of the public school systems entirely this year? We should gain some more insight when the NYSED releases private school and home school data later this winter.