The average well water temperature is 35 to 77 F (1 to 25 C). The well depth and the overall groundwater temperature of the area are the main factors that affect a well’s temperature.
The water in shallow wells (25 feet deep) is generally warm compared to deeper wells. The deeper wells have cold water, and the temperature decreases by approximately 1 F as your well goes 60 – 65 F deep.
Well Water Temperature in Shallow Wells
The water temperature in 30 – 60 deep wells is usually 2 to 3 F higher than the annual mean temperature of the locality. For example, if the annual mean temperature in your area is 65 F (18 C), the well water temperature will be 67 – 68 F (around 20 C).
Well Water Temperature in Deep Wells
The average depth of water wells in the US is 100-800 feet. Some wells may go up to 3000 feet in depth depending on water availability and how big an aquifer you want to tap. Water in deep wells is colder than shallow wells. The water temperature drops as the well depth increases.
Well Water Temperature in Cold vs. Hot Regions
Well water temperature in states like Alaska, North Dakota, Minnesota, Montana, Wyoming, Idaho, and Maine will be cold compared to Florida, Texas, Louisiana, and Georgia.
Well water temperature usually remains constant throughout the year because the soil is a very poor conductor of heat, and the sun has little effect on groundwater temperature.
The well water temperature may change due to a geographical event or if a groundwater stream disrupts the natural flow of water. It rarely happens, and the temperature usually stays the same throughout the year.
Why does Well Water Temperature feel different during Summer and Winter?
You may have noticed that well water feels hot during winter and cold in summer. It is due to the difference between air and groundwater temperatures. The underground water temperature rarely changes.
This explanation is valid for only moderate climate regions such as California, Nevada, New Mexico, and Arizona. It does not apply to states like Alaska, where the temperature falls to -20 F. The groundwater becomes cold as ice and no longer feels warm.
Can Well Water Freeze? Does Cold Weather Affect your Well?
The water in the well doesn’t freeze because it is way below the freezing point. However, the water inside the pipes can freeze. It is due to external temperature and not water temperature. You can unfreeze the pipes yourself in most cases.
Can I Control the Well Water Temperature?
You cannot adjust the temperature of the water inside the well. Most people use water heaters to control water temperature. A water heater is typically installed at the point of use. Some people also install large water heaters for whole-house use.