Grey River – current water temperature and swimming conditions
This page provides information about the current water temperature at Grey River in West Coast 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 Grey River today is 14°C.
Water Temperature in Grey 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 Grey River have generally increased, although a slight cooling trend has set in over the last week.
According to our forecast, the water temperature in Grey River will be 11.8°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 | 13.7°C | 11.5°C | |
| May 7 | 13.7°C | 11.5°C | |
| May 8 | 14.0°C | 11.5°C | |
| May 9 | 14.0°C | 11.5°C | |
| May 10 | 14.1°C | 11.5°C | |
| May 11 | 14.1°C | 11.5°C | |
| May 12 | 14.0°C | 11.5°C | |
| May 13 | 12.6°C | 11.5°C | |
| May 14 | 13.6°C | 11.5°C | 13.6°C |
| May 15 | 11.5°C | 13.3°C | |
| May 16 | 11.5°C | 13.1°C | |
| May 17 | 11.5°C | 12.8°C | |
| May 18 | 11.5°C | 12.6°C | |
| May 19 | 11.5°C | 12.3°C | |
| May 20 | 11.5°C | 12.0°C | |
| May 21 | 11.5°C | 11.8°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 | 22°C |
| February | 13°C | 18°C | 23°C |
| March | 10°C | 16°C | 22°C |
| April | 9°C | 14°C | 19°C |
| May | 7°C | 12°C | 16°C |
| June | 4°C | 8°C | 12°C |
| July | 4°C | 8°C | 11°C |
| August | 6°C | 9°C | 12°C |
| September | 7°C | 11°C | 14°C |
| October | 7°C | 12°C | 17°C |
| November | 7°C | 13°C | 19°C |
| December | 9°C | 16°C | 23°C |
Grey River: Water Temperature by Location
Stillwater
Grey River: Weather Forecast
May 15
May 16
May 17
May 18
May 19
May 20
Location & Local Information
Source Southern Alps (Saint Arnaud Range) • location Lake Christabel, New Zealand Mouth Tasman Sea • elevation 0 m (0 ft)
The Grey River, known as Māwheranui, flows through the West Coast Region of the South Island, running from the Southern Alps to the Tasman Sea at Greymouth. Fed by alpine streams and heavy West Coast rainfall, the river remains cool for much of the year. In winter, water temperatures are typically around 7–10°C. During spring, snowmelt and frequent rain keep the river brisk, generally between 9 and 13°C. In summer, especially in January and February, temperatures in slower-moving sections may rise to about 14–18°C on settled days, although the main channel often feels cooler due to strong flow. By autumn, temperatures usually ease back to roughly 10–15°C. Rainfall events can quickly lower temperatures and significantly increase river levels.
Swimming Conditions
Swimming is allowed in parts of the Grey River, but conditions require caution. The river is large, with powerful currents, deep channels and changing gravel beds. Even in summer, the water can feel cold, particularly in the main flow. More suitable swimming spots are usually found in sheltered side channels or calm river edges when temperatures approach the mid to high teens and levels are stable. It is important to avoid swimming during or after heavy rain, as flows can rise rapidly and water clarity may decrease. Checking local river conditions before entering the water is recommended.