Yes, it's possible for the water in a swimming pool to be cold in the morning.
Based on typical factors affecting pool temperature, and specifically the information provided, the temperature of pool water in the morning can indeed be quite low.
Here's why the morning chill affects pool water:
- Lack of Sun Exposure: A primary reason for cold morning pool water is that the Sun hasn't been out for long enough to heat the water. The heat absorbed throughout the day dissipates somewhat overnight, and the morning sun is often not intense enough or present for a sufficient duration to significantly warm the water back up immediately.
- Overnight Cooling: Water naturally loses heat to the cooler air overnight through evaporation and convection. This effect is more pronounced after clear nights with little wind.
Swimming in water that feels too cold can have consequences. The reference notes that if you end up feeling too cold while you're swimming, it could lead to loss of muscle control. This highlights the importance of being aware of the water temperature before getting in, especially early in the day.
Considerations for Morning Swimmers:
- Pool Material: The reference specifically mentions "fibreglass pool," suggesting that the material might influence heat retention or absorption, although the core reason (lack of sun) applies generally. Different pool types (concrete, vinyl liner) might vary slightly in how quickly they heat or cool.
- Ambient Temperature: The air temperature overnight and in the morning plays a significant role. A cold night will naturally lead to colder water.
- Heating Systems: Pools with heating systems (like solar covers, heat pumps, or gas heaters) will be less susceptible to morning coldness, depending on whether the system was running or the cover was used overnight.
In summary, while not guaranteed to be cold every single morning, the conditions are often ripe for swimming pool water to be cooler than desired early in the day due to insufficient sunlight and overnight cooling.
