Here are a few possible reasons why your car is leaking water from the exhaust:

1. Condensation: As the engine burns fuel, it produces water vapor as a byproduct. This is completely normal, and on a cold day, the water vapor can condense into liquid droplets inside the exhaust system. When you start the car, the droplets may be pushed out of the tailpipe as liquid water, which is what you may see dripping. Condensation is more likely to happen if you only drive short distances and don't let the engine warm up fully.

2. Internal engine issues: In some cases, water leaking from the exhaust can be a sign of more significant engine problems. If coolant is leaking into the combustion chamber, it can mix with the fuel and produce a white or grayish smoke. This can also cause the engine to overheat, leading to additional damage. If you suspect an internal engine problem, it's best to take your car to a mechanic as soon as possible.

3. Failed head gasket: A head gasket is a critical component that seals the engine's cylinders and prevents coolant from mixing with oil and fuel. If the head gasket fails, coolant can leak into the combustion chamber and cause steam to come out of the exhaust. This can also cause the engine to overheat and lead to significant damage.

4. Cracked cylinder head or engine block: If the engine block or cylinder head cracks, coolant can leak into the combustion chamber, leading to the same symptoms as a failed head gasket. Cracks can be caused by overheating, improper engine maintenance, or simply age and wear.

5. Failed water pump: The water pump is responsible for circulating coolant throughout the engine to keep it from overheating. If the water pump fails, coolant may not be able to circulate properly, leading to overheating and potential engine damage. You may notice steam coming from the tailpipe, as well as other signs of engine overheating, such as a high-pitched whining noise or dashboard warning lights.

6. Blocked catalytic converter: The catalytic converter is responsible for reducing emissions by converting harmful gases into less harmful ones. However, if the catalytic converter becomes blocked or clogged, it can cause a buildup of pressure in the exhaust system. This pressure can cause water vapor to condense and become liquid, leading to water dripping from the tailpipe.

7. Cool, humid weather: As mentioned earlier, condensation is a common reason for water dripping from the exhaust. If the weather is cool and humid, there may be more moisture in the air, leading to increased condensation in the exhaust system. This is usually nothing to worry about and should clear up once the engine warms up.

In conclusion, there are several potential reasons why your car may be leaking water from the exhaust. While some causes are more serious than others, it's always best to have your car checked out by a mechanic if you notice any unusual symptoms. Regular maintenance and upkeep can also help prevent issues from arising in the first place.