A brief summary of climate and hydrological conditions in the region.

This service is regularly updated during periods in which closer monitoring is required (regardless of time of the year), in recognition that there is potential for dry spells, or irregular hydrological recharging. It does not define an official council position on drought or drought declaration. Outside of dry periods, less frequent updates synchronise with our latest seasonal outlooks.

Updated 16 June 2026

Next update due when there is a significant change of conditions or a new seasonal outlook.

Background

Autumn 2026 was characterised by a dying La Niña with residual easterly flows. There were occasional atmospheric river events and flash flooding thunderstorms around the region. It was a very variable season, albeit mostly mild, continuing the overall tendency for above average rainfall on the eastern Wairarapa coast. Winter, however, started with a wet signal on the west coast, with increased westerly flows. This tendency for predominant westerly flows should continue to gather momentum as a new El Niño is expected to develop going into late winter and early spring.  

Heatmap showing rainfall as a percentage of the average in the Wellington Region in Autumn 2026; rainfall is highest around Wellington City and Lower Hutt, and eastern Wairarapa
Autumn rainfall anomalies show above average rainfall for Wellington and eastern Wairarapa. Credits: Greater Wellington
Autumn 2026 anomaly open_in_new

Current situation

Soil moisture levels were sitting at the above average mark around mid-June, with a more westerly flow rainfall regime starting to take place. Groundwater levels are generally holding up and tracking well within the historical normal range for early winter. 

Meteorological outlook

International climate models are predicting that a new El Niño (i.e. positive ENSO event) will continue to develop and eventually turn into a strong event towards the end of the year, with potentially significant impacts. While there is some uncertainty regarding the maximum strength of this event, various models suggest that it could be as strong as the historical 1982-1983 and 1997-1998 El Niños or possibly turn out to be one of the strongest El Niños in recorded modern history. Traditionally, the Wairarapa tends to be drier than normal during strong El Niños, even though the severity of the dryness would depend on the extent of the local oceanic temperature anomalies, which currently remain warm and hence could work against a more severe dryness. Basically, it is still too early to know for sure how dry the region will likely be during the peak phase of this event, but we strongly recommend a close monitoring of how the hydrological system will evolve between winter and early spring. Apart from the Equatorial Pacific, a closer look into the Indian Ocean Dipole going into spring, and the local sea surface temperature anomalies around New Zealand by September (which can act to ameliorate the traditional ENSO impacts as mentioned above) will also help determine the likely severity of the impacts later this year and going into 2027. At this stage, the chance of at least some localised drought in the Wairarapa later in the year or into summer 2027 can be estimated to be around 60%, based on historical data and the likely strength of the incoming El Niño combined with other climate drivers. 

Climate change

The ‘normal’ longer-term water balance is becoming increasingly hard to maintain quite possibly due to climate change influences, and increased high frequency climate variability, with more unreliable weather patterns. Droughts are expected to become more severe and frequent in the Wellington region, particularly in the Wairarapa. Even if international climate policy efforts were to successfully contain global warming under 1.5-2 degrees (the Paris Agreement’s ambition), it is important that we enhance our water resilience and be prepared for more unreliable climate patterns with both extreme dry and extreme wet periods. We note that the warming of the land also means that evapotranspiration will greatly increase, so the soil will likely need more ongoing rain to maintain ideal moisture levels, compared to what it has needed in the past.

View the latest national drought index state

View the national drought forecasting dashboard

View the latest seasonal report:

Browse the data

Anomaly Maps

How different has recent rainfall/soil moisture been compared with the same time in previous years?

30 Day Rainfall Anomaly

90 Day Rainfall Anomaly

1 Day Soil Moisture Anomaly

30 Day Soil Moisture Anomaly

 

Site-specific graphs

Cumulative rainfall/soil moisture totals for indicator sites compared with historical averages and other recent years. 
Area Rainfall Soil Moisture
Kapiti Coast (lowland) Otaki at Depot  
Kapiti Coast (high altitude) Penn Creek at McIntosh  
Porirua Horokiri Stream at Battle Hill  
Wellington City Kaiwharawhara Stream at Karori Reservoir  
Hutt Valley (upper catchment) Hutt River at Kaitoke Headworks  
Upper Hutt Upper Hutt at Savage Park Upper Hutt at Savage Park AQ
Wainuiomata Wanuiomata River at Wainui Reservoir  
Wairarapa (high altitude) Waingawa River at Angle Knob  
Wairarapa Valley (north) Kopuaranga River at Mauriceville  
Wairarapa Valley (Masterton) Ruamahanga River at Wairarapa College Wairarapa College AQ
Wairarapa Valley (south) Tauherenikau River at Racecourse Tauherenikau River at Racecourse
Wairarapa (north-eastern hills) Whareama River at Tanawa Hut Whareama River at Tanawa Hut
Wairarapa (south-eastern hills) Waikoukou at Longbush Waikoukou at Longbush
Updated June 15, 2026 at 4:36 PM

Get in touch

Phone:
0800496734
Email:
info@gw.govt.nz