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 11.7°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
❌ As of today, the minimum water temperature ranges from 50°F (10°C) to 54°F (12°C). The water is slightly warmer, but still cool for most people. Swimming in such conditions is possible, but for most people, the time spent in the water should be limited to avoid hypothermia. Even experienced swimmers may feel discomfort if they stay in the water for too long. To improve comfort and safety, a wetsuit can be used. 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 |
|---|---|---|---|
| OCT 5 | 12.5°C | 9.5°C | |
| OCT 6 | 11.6°C | 9.5°C | |
| OCT 7 | 11.9°C | 9.5°C | |
| OCT 8 | 11.7°C | 9.5°C | |
| OCT 9 | 11.5°C | 9.5°C | |
| OCT 10 | 11.6°C | 9.5°C | |
| OCT 11 | 12.7°C | 9.5°C | |
| OCT 12 | 12.4°C | 9.5°C | |
| OCT 13 | 9.5°C | 11.6°C | |
| OCT 14 | 9.5°C | 11.5°C | |
| OCT 15 | 9.5°C | 11.4°C | |
| OCT 16 | 9.5°C | 11.3°C | |
| OCT 17 | 9.5°C | 11.2°C | |
| OCT 18 | 9.5°C | 11.0°C | |
| OCT 19 | 9.5°C | 10.9°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
October 13
October 14
October 15
October 16
October 17
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.