Which phrase indicates a lack of sunlight and overcast conditions?

The phrase that indicates a lack of sunlight and overcast conditions is “It's cloudy.” This phrase directly describes a situation where clouds cover the sky, reducing the amount of sunlight that reaches the ground. When it is cloudy, typically the weather is dull and grey, which often connotes a lack of brightness associated with sunny weather.

The other choices describe different weather conditions. A declaration of "It's hot" suggests warmth, possibly indicating sunny weather rather than overcast. "It's sunny" clearly denotes the presence of sunlight, which contradicts the idea of lack of light. "It's chilly" could describe a cool temperature regardless of the cloud cover, but it does not specifically indicate overcast conditions or a lack of sunlight. Therefore, "It's cloudy" is the most accurate representation of a situation characterized by overcast skies and limited sunlight.