What is the incubation period for H3N2?

1 - 4 days, usually. Incubation period of most strains of influenza is 1-4 days, typically 2, but can be as long as 7 for a variant of H3n2. H3N2 is a subtype of influenza A.. See http://www.cdc.gov/flu/professionals/acip/clinical.htm and see http://www.michigan.gov/mdch/0,4612,7-132-8347-311534--,00.html and see http://en.wikipedia.org/wiki/Influenza_A_virus_subtype_H3N2.
Flu. The incubation period for influenza (of which H3N2 is one strain) is 1 to 4 days. Typical incubation period is 2 days.