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 29 October 2026
Next update due when there is a significant change of conditions or a new seasonal outlook.
El Niño to reach maturity early summer. A dry November likely for Wairarapa
View Earth Sciences NZ's El Niño tracker
The daily El Niño tracker by ESNZ (upper panel) shows that the current event (red line on the graph) is on track to either surpass or peak closely to the historical 1982/1983 El Niño. Current forecasts suggest that the event will peak early summer and start declining into autumn. The latest global SST anomalies are shown immediately above, where we can see that despite the ENSO signature in the Pacific Ocean, the water temperatures remain above average immediately around New Zealand, which might work against a more severe dryness. For dry historical El Niño years, the local oceanic water temperatures have been traditionally well below average such as in 1982/83 and 1997/98. Credits: ESNZ and NOAA.
Background
Winter and early spring were characterised by large temperature fluctuations across the region, as well as extreme rainfall episodes and isolated downpours during severe thunderstorms. Parts of the Wairarapa are still recovering from flood damage. From October onwards, a more definite drying trend started to emerge, with the daily soil moisture anomaly field showing a slightly below average signal on the north-eastern part of the Wairarapa by the end of the month.
Current situation
Soil moisture levels were sitting at around normal for most of the region by late October, with a limited area of anomalous deficit in the north-eastern part of the Wairarapa. A strong westerly flow typical of El Niño springs is now finally established over the region, with a warming and drying trend starting to develop east of the ranges. October rainfall has ranged between 30 and 50% of the long-term average in the northern Wairarapa and seasonal deficits are starting to emerge. Rivers flowing from the Tararua Range are generally holding up after recent high elevation rainfall, although valley floor streams and hill country rivers in northern and eastern Wairarapa especially have been in recession for most of October. These watercourses could fall quite quickly towards restriction levels with no substantive rain in the outlook. Likewise for groundwater; levels are now starting to tend towards lower than normal for this time of year.
Meteorological outlook
The El Niño event is on track to either surpass or peak closely to the historical 1982/1983 El Niño. Current forecasts suggest that the event will peak early summer and start declining going into autumn. A drying trend is expected to continue to evolve into November, with very little rain predicted by the long-range weather forecasting models. In terms of how much this will escalate, each El Niño is different and impacts in our region can be variable and ‘hit and miss’, compared to other parts of New Zealand and the world. The latest projections for the synoptic flow anomalies depict a persistent, vigorous westerly flow strengthening towards the end of the year, with an anticyclone prevailing over the Tasman Sea. While this configuration should lead to some dryness east of the ranges, whether this set up will turn into a more significant summer drought remains unclear. A warmer ocean in our region might work to partially counteract traditional ENSO impacts, through increased moisture from evaporation.
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| Summer rainfall anomalies for the historical strongest El Niños on record of 1982/83 and 1997/98. We can see that both cases had rainfall above average over the Tararua ranges and around Kāpiti, with below average rainfall in the Wairarapa, south of Wellington city and Baring Head. Credits: Greater Wellington | |
The table below summarises potential El Niño impacts for the Wellington region during the coming spring and summer months. In light of the potential for extended dryness over the summer months in the Wairarapa, we strongly recommend a continuous monitoring of how the hydrological conditions will evolve during spring, along with the seasonal outlooks and daily data available on our seasonal climate portal and also by Earth Sciences New Zealand.
| Projected El Niño climate impacts for spring and summer – global and region wide summary | Spring 2026 | Summer 2026-2027 |
|---|---|---|
| High confidence global projections | There is high confidence that this El Niño will be one of the strongest in recorded history, with severe global impacts. However, the Wellington Region is in a transition area, and El Niño impacts are normally only mild for us compared to Hawkes Bay, Canterbury and other areas of the world such as South America, California, Australia and South-east Asia | The event, albeit very strong, is predicted to mature early in summer and start to rapidly decrease in intensity towards autumn, even though its effects could still be felt for longer. |
| Overall projected regional Impacts | Increased westerly winds and gusts, moderate to severe drying in the Wairarapa (especially eastern coast) and Baring Head area. Likely low flows east of the main ranges, and increased fire risk in several areas including Baring Head and Wairarapa, especially as a result of increased winds | As per spring, with drying effects reaching their peak and likely starting to decrease into autumn |
| Areas of uncertainty | Every El Niño is unique and not every event will have a clear dry pattern in spring. Climate change has warmed the oceans around New Zealand, and warmer waters might work to partially counteract the traditional effects of a more severe drying in our region | Every El Niño is unique and not every event will have a clear dry pattern in summer. Climate change has warmed the oceans around New Zealand, and warmer waters might work to partially counteract the traditional effects of a more severe drying in our region |
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 2026 summary Spring 2026 outlook
date_range Published 24 Sep 2026
Download now (PDF 1.9 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