You might have observed that well water or water pulled out from deep underground using water pumps is felt cold in summer while hot in winter season and you might be wondering why this happens! The reason for this phenomenon is very simple.
Actually, temperature of underground water remains almost constant through out the year because water table is far below from the surface of Earth. Sun is not able to heat such deep underground water. The temperature of underground water could be 10-20 degree Celsius (50-68 °F). It is different for different geographical regions. So, if temperature outside is suppose 40 degree Celsius (104 °F) but underground water is only 15 °C (59 °F), you will feel it cold. In winter, if temperature on surface of Earth is 0 or below 0 °C (32 °F), well water with over 15 degree Celsius (59 °F) temperature will definitely be felt as warm.
The same phenomenon also happens in case of tube well water and the reason remains the same. Tube well which is used for irrigation purposes and to supply water to towns is a type of well having a narrow pipe going down the Earth to underground aquifer. Water is then pulled up using water pumps.
It has been observed that water from deeper well is cooler than the well which is just few feet deep. We have also observed a noticeable temperature difference between well water at cooler regions and in hot deserts. Surrounding temperature has great impact on wells especially open wells.
Note that the regions with little to no rainfall have got water table at extreme depth and water is also salty and unfit for drinking. Places where there are rivers or large streams flowing have got sweet underground water due to the constant percolation of fresh water from top.
Below is the illustration of few water wells. To get water from underground you need to keep digging till some better quality water is obtained.
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| Types of water wells. Levels and depth of underground water. |
Sometimes, the underground water which is pumped out is very hot. It is a rare case but naturally possible. It happens when underground water comes in contact with burning hot rocks or magma. Hot water falls, geysers and hot natural fountains are also formed due to the result of same contact between water and magma or hot rocks.
ABDUL WAHAB
Not understanding clearly I am confused in that that when in summer season the temperature is 40 to 45 and underground water temperature is 15 to 20 C how it’s possible that it is cold it is high temperature for water but still cool?….
Talal A.
You should turn on room AC at 16 C on hot summer day and when room temperature gets to that temperature you will actually start feeling cold. That’s how you feel 15 C water cold in summer. You may use a thermometer to measure exact temperature of fresh underground water. Its temperature varies from place to place.
shivam
Thanks. Explained very well.
chijioke
What about water drawn from a well in the morning?
Vivek Raj.
We have already known that the temperature of under ground water is always 10_20 degree Celsius. When it’s winter season.then automatically we feel that, the underground water is so hot. Because the temperature in winter season is about 0 degree Celsius. And this process is also in summer season. The temperature of summer season is 30-40.and the temperature of under ground water is 10-20 degree Celsius. Then we automatically feel that the under ground water is so cold.
Girdhari singh
If water is coming from deep inside earth and we also know that the inside of earth is hot….why that water comes out cool. I don’t understand this plz explain anyone :)
Talal A.
Earth is hot several hundred kilometers below. We dig wells and pull out water from just few hundred meters below and at that depth Earth is cool.
haris
I also had same understating even before
reading this article….
VP Srinivasan
Thanks for the above post.
nitin
what about the well water whose source is pond or not from so deep underground water
is it some sort of geothermal power?
Talal A.
The water that seeps down from pond automatically gets cooled once it reaches the deep water bed. The external temperature on surface of Earth won’t affect it much unless there are hot rocks underneath.
If pond water is being pored in open well, then heat from sun will heat that water as well as it is exposed to external atmosphere.
Naveed
I had same understating even before reading this article …………yep
Aaqib shah
Now I really understood.