Many buildings will have to be checked for damage.
Staff of central Wellington organisations are advised to stay home and get in touch with their employers for further instructions.
Widespread liquefaction has been reported on reclaimed land around the waterfront - and reported damage to waterfront buildings.
Hotel guests or apartment dwellers who are out of doors in the Wellington CBD after this morning's earthquakes can find temporary refuge at the BizDojo Centre, 115 Tory Street.
Temporary refuge is also available, slightly further out of town, at Houghton Valley School.
Meanwhile, residents of beachfront or coastal areas are urged to stay inland or on high ground due to the continuing threat of a tsunami following this morning's earthquakes.
The advice from the Ministry of Civil Defence is that people living in the tsunami 'red zone' - very close to sea level or adjacent to beaches and the coast - should evacuate inland or to higher ground until further notice.
Affected spots include seaside areas of Wellington's south coast, Seatoun and Eastbourne.
The Wellington City Council Emergency Operations Centre and the Wellington Region ECC has been activated following the earthquake just after midnight.