Whanganui River – current water temperature and swimming conditions
This page provides information about the current water temperature at Whanganui River in Manawatū–Whanganui. 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 Whanganui River today is 15°C.
Water Temperature in Whanganui River: Daily Trends, Historical Records, and Forecast
Water Temperature Over the Last 30 Days
Water temperatures in Whanganui River have been on a steady rise over the past month and have continued to climb over the last week.
According to our forecast, the water temperature in Whanganui River will be 10.0°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 |
|---|---|---|---|
| Jul 2 | 14.0°C | 9.3°C | |
| Jul 3 | 13.9°C | 9.3°C | |
| Jul 4 | 13.8°C | 9.3°C | |
| Jul 5 | 13.7°C | 9.3°C | |
| Jul 6 | 13.7°C | 9.3°C | |
| Jul 7 | 14.9°C | 9.3°C | |
| Jul 8 | 14.9°C | 9.3°C | |
| Jul 9 | 15.0°C | 9.3°C | |
| Jul 10 | 15.0°C | 9.3°C | 15.0°C |
| Jul 11 | 9.3°C | 14.3°C | |
| Jul 12 | 9.3°C | 13.6°C | |
| Jul 13 | 9.3°C | 12.9°C | |
| Jul 14 | 9.3°C | 12.2°C | |
| Jul 15 | 9.3°C | 11.4°C | |
| Jul 16 | 9.3°C | 10.7°C | |
| Jul 17 | 9.3°C | 10.0°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 | 17°C | 22°C | 27°C |
| February | 13°C | 20°C | 27°C |
| March | 13°C | 19°C | 24°C |
| April | 10°C | 15°C | 19°C |
| May | 8°C | 12°C | 16°C |
| June | 4°C | 9°C | 14°C |
| July | 4°C | 9°C | 13°C |
| August | 6°C | 10°C | 13°C |
| September | 8°C | 12°C | 16°C |
| October | 10°C | 15°C | 19°C |
| November | 11°C | 17°C | 23°C |
| December | 14°C | 20°C | 25°C |
Whanganui River: Water Temperature by Location
🔗 Whanganui
🔗 Taumarunui
Whanganui River: Weather Forecast
July 10
July 11
July 12
July 13
July 14
Location & Local Information
Source Mount Tongariro Mouth Tasman Sea • coordinates 39°56.89′S 174°59.22′E • elevation Sea level Length 290 km (180 mi)
The Whanganui River is one of New Zealand’s longest navigable rivers and a defining feature of the Manawatū–Whanganui, flowing from the central plateau to the Tasman Sea. Water temperatures vary along its length and through the seasons, influenced by altitude, rainfall, and river flow. In summer, temperatures typically sit around 17–21 °C, feeling comfortable in slower, sun-exposed reaches. Spring and autumn usually bring cooler conditions of about 13–17 °C. In winter, the river cools noticeably, often dropping to roughly 9–12 °C, which feels cold and limits time in the water.
Swimming Conditions
Swimming in the Whanganui River is allowed and enjoyed in many areas, particularly during summer when temperatures are at their warmest. Calm sections near riverbanks, beaches, and recognised access points are commonly used for swimming and cooling off on hot days. The river’s character changes along its course, with some stretches slow and wide, while others are narrower with stronger currents. After heavy rain, water levels can rise quickly and clarity can reduce, affecting swimming conditions. For these reasons, swimming is best suited to settled summer weather and well-known locations. Outside the warmer months, cooler temperatures and increased flow make swimming less appealing for most people. Overall, the Whanganui River offers good seasonal swimming opportunities, especially in summer, alongside its wider recreational and cultural importance.