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 15 September 2025
Next update due when there is a significant change of conditions or a new seasonal outlook.
Background
Winter was predominantly mild and wet until July. In August, strong southerlies carried polar air masses into New Zealand as a prominent feature, with severe frosts inland, and a reasonable snow cover developing in the Tararuas. On average, seasonal rainfall was around 20% higher than the long-term average west of the ranges, and around 20% lower than the long-term average in the central Wairarapa (see map below). Lingering effects of a blocking anticyclone east of New Zealand, with some intermittent easterly flow, continued to be observed amongst the backdrop of sharp contrasts highlighted above. From September onwards, proper spring westerly flow took over, with largely below average rainfall especially east of the ranges.
Current situation
Soil moisture levels were sitting at about average at the beginning of spring, benefiting from a good replenishing that had carried over from autumn. Most of the high elevation areas within the catchments received good replenishment over winter.
Meteorological outlook
International climate models are predicting strong westerlies at the beginning of spring as already observed in September, eventually shifting to an easterly flow from October onwards. This shift to easterlies is predicted to be associated with a La Niña blocking anticyclone (high pressure) developing to the south-east of New Zealand. We note that this abrupt circulation shift is being predicted by most international climate models examined for this assessment, even though the exact timing is difficult to pinpoint. In synergy with an incoming negative ENSO, the Indian Ocean Dipole is also expected to remain in the negative phase for the remainder of the year. This combination tends to enhance La Niña easterly flows. Based on this overall changing picture, we are expecting dry conditions to develop in the Wairarapa in the first half of spring, eventually reverting to normal to wet under easterly flows. As such, the risk of a major meteorological drought is currently low for the remainder of the year.
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:
Climate drivers and seasonal outlook for the Wellington Region - Winter 2025 summary Spring 2025 outlook
date_range Published 12 Sep 2025
Download now (PDF 1.7 MB) get_appBrowse the data
Anomaly Maps
How different has recent rainfall/soil moisture been compared with the same time in previous years?
Site-specific graphs
| 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 |
Get in touch
- Phone:
- 0800496734
- Email:
- info@gw.govt.nz