During the summer of 2012-2013, anticyclones dominated the New Zealand area. Many places had little or no rainfall since early February.
The map below shows the average mean sea level pressure over the New Zealand area over Jan/Feb 2013. There's no doubt about the pressure being high and not changing very much. Because this map shows averaged pressures, we don't see the few troughs that passed across Aotearoa New Zealand during that time.