Wairau River – current water temperature and swimming conditions
This page provides information about the current water temperature at Wairau River in Marlborough Region. Here you can view recent temperature trends on a 30-day chart, check typical monthly water temperature ranges, and compare today’s reading with historical averages for this date. A 7-day water temperature forecast, local weather conditions, and an overview of swimming suitability are also included.
Current Water Temperature
The water temperature in Wairau River today is 12°C.
Water Temperature in Wairau River: Daily Trends, Historical Records, and Forecast
⚠️ River water between 10 and 15°C is cold but manageable for short swims, especially on sunny days with warm air temperatures. The moving nature of a river can make the water feel colder than the actual reading, particularly in shaded or deeper sections. Casual swimming is usually brief, with wetsuits often preferred. Windy or cool weather can significantly reduce comfort, even when the air temperature is mild.
Water Temperature Over the Last 30 Days
Water temperatures in Wairau River have been gradually cooling over the past month, with a further drop recorded during the last week.
According to our forecast, the water temperature in Wairau River will be 7.7°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Water Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| May 6 | 12.4°C | 7.1°C | |
| May 7 | 12.4°C | 7.1°C | |
| May 8 | 12.7°C | 7.1°C | |
| May 9 | 12.7°C | 7.1°C | |
| May 10 | 13.0°C | 7.1°C | |
| May 11 | 13.0°C | 7.1°C | |
| May 12 | 12.6°C | 7.1°C | |
| May 13 | 11.4°C | 7.1°C | |
| May 14 | 11.9°C | 7.1°C | 11.9°C |
| May 15 | 7.1°C | 11.3°C | |
| May 16 | 7.1°C | 10.7°C | |
| May 17 | 7.1°C | 10.1°C | |
| May 18 | 7.1°C | 9.5°C | |
| May 19 | 7.1°C | 8.9°C | |
| May 20 | 7.1°C | 8.3°C | |
| May 21 | 7.1°C | 7.7°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual river water temperatures may vary by several degrees from the reported values, particularly after heavy rainfall or periods of changing weather. Rainfall, river flow rates, and runoff from cooler upstream areas can significantly affect water temperature, especially in flowing sections and shaded stretches. Air temperature and cloud cover also play an important role, with warm, sunny conditions helping rivers warm up more quickly. As a result, noticeable temperature differences can occur along the same river.
Our forecast is based on a proprietary mathematical model that takes into account real-time river temperature changes, historical data, seasonal patterns, river flow conditions, recent rainfall, and local air temperature. We also factor in broader weather conditions specific to each region of New Zealand to improve accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Today | Yesterday | A Week Ago |
|---|---|---|---|
| January | 8°C | 13°C | 18°C |
| February | 8°C | 14°C | 19°C |
| March | 7°C | 12°C | 17°C |
| April | 6°C | 12°C | 18°C |
| May | 2°C | 7°C | 12°C |
| June | 0°C | 5°C | 10°C |
| July | 0°C | 4°C | 8°C |
| August | 0°C | 5°C | 9°C |
| September | 2°C | 6°C | 10°C |
| October | 3°C | 7°C | 11°C |
| November | 5°C | 10°C | 14°C |
| December | 7°C | 12°C | 17°C |
Wairau River: Weather Forecast
May 15
May 16
May 17
May 18
May 19
Location & Local Information
Source: • location Spenser Mountains Mouth: • location Te Koko-o-Kupe / Cloudy Bay • coordinates 41°34′S 173°31′E Length 170 kilometres
The Wairau River flows from the Southern Alps across the Wairau Plains to Cloudy Bay, forming a key waterway in the Marlborough District. Water temperature varies with season, alpine inputs, and river flow. In summer, temperatures typically reach around 16–20 °C, feeling cool but refreshing, especially in slower side channels and sheltered reaches. Spring and autumn usually bring temperatures of about 12–16 °C. In winter, the river cools significantly, often dropping to roughly 7–10 °C, reflecting snowmelt and low air temperatures from the upper catchment.
Swimming Conditions
Swimming in the Wairau River is allowed and does take place during summer, mainly at known calm spots near the riverbanks. When conditions are settled, the river can be clear and inviting, making it suitable for short, refreshing swims on warm days. However, the Wairau is a braided river with changing channels and currents that can be stronger than they appear. After heavy rain or increased alpine runoff, water levels can rise quickly and clarity can reduce, making swimming unsafe. For these reasons, swimming is best limited to fine summer weather and familiar locations with gentle flow. Outside the warmer months, cold water temperatures and stronger currents generally discourage swimming. Overall, the Wairau River offers occasional summer swimming opportunities in suitable sections, while for much of the year it is better appreciated for its open landscapes, fishing, and riverside recreation rather than regular time spent in the water.