Well water is usually between 15-20 degrees Celsius. This is because well water is underground and deep, and its temperature is relatively stable compared to the atmospheric temperature. However, in some special cases, the temperature of well water may be related to the environmental and geological conditions of the area.

In some areas where well water is used as drinking water, the local water source may be affected by climate, soil and hydrological conditions. For example, in the southern coastal areas, due to the effect of tides, groundwater moisture will be affected by river moisture, so the temperature of well water may be higher in some areas.

The temperature of well water will be affected by the geological environment of the area. For some areas with frequent volcanic activity, the temperature of well water may increase significantly. In addition, the temperature of well water around underground hot water areas such as hot springs will be higher than that of ordinary well water.

In short, under normal circumstances, the temperature of well water is between 15-20 degrees Celsius, which will be affected by many factors. For example, the environment, geological conditions of the area and the impact of the surrounding nature on the local area will affect the temperature of well water.