When does pollen typically rise in the atmosphere?

Pollen typically rises in the atmosphere during warm air conditions, which usually occur later in the morning and into the afternoon as temperatures rise. During warm weather, thermal updrafts are created, causing pollen from plants to be lifted into the air. This is particularly relevant for many types of grass and flowering plants, which release pollen in response to warmth and sunlight.

The other options do not accurately reflect the typical patterns of pollen release. For example, after sunset, temperatures tend to drop, and many plants do not release pollen until the warmth returns. At dawn, while some pollen may begin to rise, it is not as significant as in the warmer parts of the day. Rainfall tends to wash pollen out of the air rather than contribute to its rise, as moisture can cause pollen grains to become heavy and settle. Thus, the correct answer reflects the natural behavior of pollen release in relation to temperature and atmospheric conditions.