"This is that time of year where they come in, especially the younger ones.
"They sort of arrive for a winter holiday, if you like, and get away from the harsh conditions from the surf," he said.
Mr Milham said examples of yesterday's unusual spot for a nap were "few and far between".
"Most of the time we are just getting calls from sightings of seals on the beach, especially from people who might not be familiar with seal behaviour and think that something's wrong."
Earlier this year, seals made headlines when they appeared in spots such as a Papakura McDonald's drive-thru and Papakura Pak 'n Save.
Mr Milham said the strangest local spot he had ever heard of a seal ending up in was on someone's couch in Welcome Bay a few years ago after entering the house via a cat door.
Department of Conservation Ranger Pete Huggins said many people were surprised to see seals on land but they were actually the new normal for the Bay. "They are breeding here, returning to the sort of population levels seen in New Zealand, before the fur trade virtually wiped them out."
If someone spots a seal badly injured, caught in netting or being harassed, they are asked to call the DoC Hotline on 0800 362468, Mr Huggins said.
It is also important to keep dogs on a leash and not let them harass or injure a seal, because seals are protected under New Zealand law. "Otherwise, just admire from a distance."
DoC recommends people give seals plenty of room, at least 20m, so they can rest naturally.
Other seals live in the Bay year round, being born and raised on offshore islands such as Motunau, Tuhua and Motuhora (Plate, Mayor and Whale Islands).
