Waiau River – current water temperature and swimming conditions
This page provides information about the current water temperature at Waiau River in Southland 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 Waiau River today is 12°C.
Water Temperature in Waiau 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
Over the past 30 days, water temperatures in Waiau River have generally increased, although a slight cooling trend has set in over the last week.
According to our forecast, the water temperature in Waiau River will be 12.0°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 | 12.6°C | 12.0°C | |
| May 7 | 12.6°C | 12.0°C | |
| May 8 | 12.8°C | 12.0°C | |
| May 9 | 12.8°C | 12.0°C | |
| May 10 | 11.4°C | 12.0°C | |
| May 11 | 11.4°C | 12.0°C | |
| May 12 | 11.2°C | 12.0°C | |
| May 13 | 12.5°C | 12.0°C | |
| May 14 | 12.0°C | 12.0°C | 12.0°C |
| May 15 | 12.0°C | 12.0°C | |
| May 16 | 12.0°C | 12.0°C | |
| May 17 | 12.0°C | 12.0°C | |
| May 18 | 12.0°C | 12.0°C | |
| May 19 | 12.0°C | 12.0°C | |
| May 20 | 12.0°C | 12.0°C | |
| May 21 | 12.0°C | 12.0°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 | 13°C | 18°C | 23°C |
| February | 13°C | 18°C | 23°C |
| March | 11°C | 16°C | 20°C |
| April | 10°C | 14°C | 17°C |
| May | 9°C | 12°C | 15°C |
| June | 5°C | 9°C | 12°C |
| July | 5°C | 8°C | 10°C |
| August | 5°C | 8°C | 11°C |
| September | 6°C | 9°C | 12°C |
| October | 7°C | 11°C | 14°C |
| November | 9°C | 13°C | 16°C |
| December | 10°C | 15°C | 20°C |
Waiau River: Weather Forecast
May 15
May 16
May 17
May 18
May 19
Location & Local Information
The Waiau River flows from Lake Te Anau through western Southland before reaching Te Waewae Bay, making it one of the major rivers in the Southland Region. Water temperature is influenced by large lake outflows, alpine catchments, and the cool southern climate. In summer, the river typically reaches around 14–18 °C, feeling cool but refreshing during warm weather. In spring and autumn, temperatures are usually between 10–14 °C. Winter brings much colder conditions, with water temperatures often around 6–9 °C, reflecting snowmelt and low air temperatures.
Swimming Conditions
Swimming in the Waiau River is allowed, but it is generally limited to warm summer days and specific calm locations. The river is wide and powerful in many sections, with strong currents that can make swimming unsuitable outside sheltered areas near the banks. Where the river slows and widens, locals do swim in settled weather, usually for short periods due to the cool water. After heavy rain, flows increase quickly and water clarity can reduce, which affects safety and comfort. Outside the summer months, cold temperatures and stronger flows mean swimming is uncommon. Overall, the Waiau River offers refreshing but cool summer swimming opportunities for confident swimmers in suitable spots, while for much of the year it is better enjoyed for its scenery and outdoor activities rather than regular time in the water.