Lake Helena — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Helena, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Helena today is 16.7°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 60°F (15°C) to 65°F (18°C). The water is comfortable for most people, making it an ideal range for water sports enthusiasts. The temperature does not cause significant discomfort, and swimming will be pleasant for the majority. However, it's important to remember that prolonged exposure to the water can still lead to cooling, so it's essential to monitor the time spent in the water, especially for children or elderly people. It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Water Temperature Chart Over the Last 30 Days
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| SEP 14 | 17.9°C | 17.0°C | |
| SEP 15 | 17.4°C | 17.0°C | |
| SEP 16 | 16.7°C | 17.0°C | |
| SEP 17 | 16.2°C | 17.0°C | |
| SEP 18 | 15.6°C | 17.0°C | |
| SEP 19 | 15.5°C | 17.0°C | |
| SEP 20 | 15.9°C | 17.0°C | |
| SEP 21 | 16.7°C | 17.0°C | |
| SEP 22 | 17.0°C | 16.7°C | |
| SEP 23 | 17.0°C | 16.7°C | |
| SEP 24 | 17.0°C | 16.7°C | |
| SEP 25 | 17.0°C | 16.8°C | |
| SEP 26 | 17.0°C | 16.8°C | |
| SEP 27 | 17.0°C | 16.8°C | |
| SEP 28 | 17.0°C | 16.8°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 1°C | 4°C | 6°C |
| February | 1°C | 4°C | 7°C |
| March | 1°C | 5°C | 9°C |
| April | 0°C | 6°C | 12°C |
| May | 4°C | 11°C | 19°C |
| June | 9°C | 14°C | 19°C |
| July | 14°C | 20°C | 25°C |
| August | 17°C | 21°C | 25°C |
| September | 13°C | 17°C | 21°C |
| October | 4°C | 10°C | 15°C |
| November | 2°C | 7°C | 10°C |
| December | 1°C | 6°C | 10°C |
Lake Helena: Water Temperature by Location
Lake Helena: Weather Forecast
September 22
September 23
September 24
September 25
Location & Local Information
Lake Helena, a shallow reservoir near Helena, Montana, experiences pronounced seasonal swings in surface water temperature because of its modest depth and wide, exposed shallows. In spring the surface typically runs cool, roughly 40–60°F (4–16°C) as snowmelt and cool air keep the water chilly. By summer the lake can warm substantially, commonly reaching about 65–75°F (18–24°C) on warm days and sometimes higher in very hot spells. In fall temperatures usually decline to about 45–60°F (7–16°C) as nights cool, and in winter the surface commonly approaches freezing, around 32–40°F (0–4°C), with ice forming in sustained cold periods.
Swimming in Lake Helena is generally permitted, but conditions make it less of a traditional beach destination than some mountain lakes. Shallow areas and abundant vegetation can reduce clarity and create soft bottoms, and water quality can vary seasonally, with occasional nuisance algae or elevated bacteria levels after heavy runoff; local health or recreation authorities may issue advisories at those times. There are few lifeguarded beaches, so swimmers should exercise caution, check current water-quality notices, and avoid swimming during visible algal blooms or poor weather.