In general there is no 'maximum' winds that an aircraft can land in, however for each type of aircraft there is a maximum "crosswind" component that the aircraft can land in. For most large commercial jets this is around 35 knots (~65 km/hour).
Cross-wind is basically the amount of the wind that is coming from the side of the aircraft. For example, if you're facing directly into the direction of the wind, then the cross-wind is zero - no matter how strong the wind is. As you turn further away from the direction of the wind the cross-wind component increases, until you're side-on to the wind in which case the cross-wind component is the entire force of the wind.
Many airlines will have limits for cross-winds that may be below the maximum allowed for a specific type of plane. Even if the winds are below the maximum allowed, it is always at the pilots discretion as to whether they will attempt a landing in current conditions - so even if the cross-winds are below all allowed maximums they may still determine that it's too dangerous and divert to another airport.
Headwinds are generally far less of an issue. Even an extremely strong head-wind will not cause any issues for a flight - and in fact they can be beneficial to landing as the plane can remain at a higher speed relative to the air when they come in to land - due to the air movement!
Tailwinds are a problem, and planes will generally not land with anything more than a relatively small tailwind, however this can be easily handled by landing in the opposite direction and turning the tailwind into a headwind!
Wellington is an airport well known for it's winds, and its frequently bumpy landing - due both to the frequent windy days in the Wellington area, but also due to the way the airport is situated on a relatively exposed hill very close to the entrance of Wellington Harbour. It has a single runway which runs roughly north-south (34/16).
Presuming the winds are northerly as you've described, this works well for the runway location. Planes can land from the south, turning the wind into a headwind. As the winds are never perfectly in the direction of the runway there will always be a small "cross-wind" component, but for the strength of winds you've mentioned it would not normally be sufficient to cause any issues.
Of course, wind conditions can change by the second, and the pilots will react on those changes, so aborted landings are not uncommon and are just a part of the pilots doing their job of landing the plane safely!
Anything is possible - but given the conditions you've described I would not expect any issues for WLG in those winds. They might lead to a few minor delays, but unless the conditions change for the worse I wouldn't expect any cancellations due to the weather.