Which of the following is a sign that the weather may change for the worse?

A sudden drop in temperature is indeed a significant indicator that the weather may be about to change for the worse. When the temperature drops unexpectedly, it can signal the approach of a cold front or other weather disturbances that might bring rain, storms, or severe weather conditions. Rapid temperature changes can affect local weather patterns and are often accompanied by other signs such as changes in wind direction or speed, increased cloud cover, or even a shift in humidity.

In contrast, a clear sky typically suggests stable weather conditions, while increased sunlight often indicates that conditions are fine, potentially leading to warmer temperatures. Similarly, a calm water surface suggests that there are no strong winds or inclement weather approaching, which can also lead to a false sense of security regarding the weather. Therefore, monitoring for a sudden drop in temperature is critical for assessing impending weather changes while out on the water.