Whanganui – current water temperature and swimming conditions

This page provides information about the current water temperature at Whanganui 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

14.0°C

Today

14.3°C

Yesterday

16.2°C

A Week Ago

The water temperature in Whanganui River at Whanganui today is 14°C.

Water Temperature in Whanganui River at Whanganui: 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 Whanganui 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 Whanganui will be 12.3°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	14.2°C	12.1°C
May 7	14.2°C	12.1°C
May 8	16.2°C	12.1°C
May 9	16.2°C	12.1°C
May 10	16.2°C	12.1°C
May 11	16.2°C	12.1°C
May 12	16.1°C	12.1°C
May 13	14.3°C	12.1°C
May 14	14.0°C	12.1°C	14.0°C
May 15		12.1°C	13.8°C
May 16		12.1°C	13.5°C
May 17		12.1°C	13.3°C
May 18		12.1°C	13.1°C
May 19		12.1°C	12.8°C
May 20		12.1°C	12.6°C
May 21		12.1°C	12.3°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: Weather Forecast

May 15

8°C / 14°C

partly cloudy

rain: 0% | wind: 23 km/h

May 16

7°C / 14°C

overcast

rain: 0% | wind: 23 km/h

May 17

5°C / 14°C

overcast

rain: 0% | wind: 19 km/h

May 18

4°C / 15°C

mainly clear

rain: 0% | wind: 19 km/h

May 19

2°C / 15°C

mainly clear

rain: 0% | wind: 7 km/h

Location & Local Information

Whanganui sits near the lower reaches of the Whanganui River, where the river widens as it approaches the Tasman Sea. Water temperatures here reflect both inland influences and coastal moderation. In summer, the river near Whanganui typically reaches around 18–21 °C, which many people find comfortable for swimming during warm weather. Spring and autumn usually see temperatures in the range of 14–18 °C. In winter, the water cools to about 9–12 °C, making it feel cold and limiting time spent in the river.

Swimming Conditions

Swimming in the Whanganui River around Whanganui is allowed and is a popular summer activity, particularly at established access points and calmer stretches close to the riverbanks. During warm, settled weather, locals often swim to cool off, especially when river levels are stable. However, the river can carry strong currents, and conditions may change quickly after heavy rainfall upstream, affecting safety and water clarity. Cooler months generally see fewer swimmers due to lower temperatures and increased flow. For these reasons, swimming is best suited to summer and to locations known for safe access. Overall, Whanganui offers good seasonal swimming opportunities in the river, while for much of the year it is more commonly enjoyed as a scenic and cultural feature of the city rather than a regular swimming spot.

Nearby Places

Frequently Asked Questions

What is the current water temperature in Whanganui River at Whanganui?

The water temperature in Whanganui River at Whanganui today is 14°C.

What is the water temperature in Whanganui River at Whanganui during the summer months?

In summer, water temperatures in Whanganui River at Whanganui at Wangi Wangi typically range from 13°C to 27°C.

Is it possible to swim in Whanganui River at Whanganui (Manawatū–Whanganui)?

Yes — you can swim in the Whanganui River at Whanganui, but the water is generally cool, often in the low-to-mid teens Celsius in summer and considerably colder at other times of year. Always check current conditions, strong flows and local water-quality advisories (avoid swimming after heavy rain), and take care with submerged hazards and changing depths.