Lake Ianthe – current water temperature and swimming conditions
This page provides information about the current water temperature at Lake Ianthe 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 Lake Ianthe today is 13°C.
Water Temperature in Lake Ianthe: Daily Trends, Historical Records, and Forecast
⚠️ Lake temperatures between 10 and 15°C are cold but can be manageable for short swims on sunny, warm days. Shallow areas may feel slightly warmer, while deeper sections remain cold and slow to warm up. Most swimmers keep sessions brief, and wetsuits are often used for comfort. Wind and cooler air temperatures can quickly reduce how pleasant the swim feels.
Water Temperature Over the Last 30 Days
Water temperatures in Lake Ianthe 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 Lake Ianthe will be 11.7°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 | 13.1°C | 11.5°C | |
| May 7 | 13.1°C | 11.5°C | |
| May 8 | 14.9°C | 11.5°C | |
| May 9 | 14.9°C | 11.5°C | |
| May 10 | 15.0°C | 11.5°C | |
| May 11 | 15.0°C | 11.5°C | |
| May 12 | 15.0°C | 11.5°C | |
| May 13 | 13.5°C | 11.5°C | |
| May 14 | 12.9°C | 11.5°C | 12.9°C |
| May 15 | 11.5°C | 12.7°C | |
| May 16 | 11.5°C | 12.6°C | |
| May 17 | 11.5°C | 12.4°C | |
| May 18 | 11.5°C | 12.2°C | |
| May 19 | 11.5°C | 12.0°C | |
| May 20 | 11.5°C | 11.9°C | |
| May 21 | 11.5°C | 11.7°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual lake water temperatures may differ from the reported values by several degrees, particularly during periods of strong winds or rapid weather changes. Wind can mix surface and deeper layers in a lake, bringing cooler water to the surface, while shallow areas may warm more quickly under direct sunlight. Air temperature, sunshine, and cloud cover strongly influence how quickly a lake heats up or cools down. These factors can lead to noticeable temperature variations across different parts of the lake.
Our forecast is based on a proprietary mathematical model that considers real-time lake temperature observations, historical trends, seasonal cycles, wind strength and direction, and region-specific air temperature. To enhance accuracy, we also incorporate data from nearby monitored locations and comparable lakes within New Zealand.
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 |
Lake Ianthe: Weather Forecast
May 15
May 16
May 17
May 18
May 19
May 20
Location & Local Information
Lake Ianthe, in the West Coast Region of the South Island, is a scenic lake surrounded by native forest and located south of Hokitika. Its water temperature reflects the region’s high rainfall and moderate coastal climate. In winter, surface temperatures are generally around 8–12°C. During spring, the lake gradually warms to approximately 12–16°C as days become milder. In summer, particularly in January and February, near-shore areas can reach about 16–20°C on calm, settled days, while deeper sections remain cooler. By autumn, temperatures typically ease back to between 12 and 16°C. Periods of heavy rain can cause short-term cooling and increased runoff from surrounding bush.
Swimming Conditions
Swimming is allowed at Lake Ianthe, and it can be an enjoyable option during the warmer months when water temperatures approach the high teens. The most comfortable conditions are usually in mid to late summer, especially on calm days with light winds. However, swimmers should be mindful that the lake is relatively deep in places and can feel cool even in summer. Choosing accessible shoreline areas and avoiding swimming during or immediately after heavy rainfall helps improve safety. Checking local conditions before entering the water is recommended to ensure a pleasant and secure experience.