It grows best when there is ample summer rain and prefers a notable cool spell during its winter resting period.

The rainy, stifling weather had passed in favor of a cooler spell.

The Saturday-morning forecast said widespread thunder, followed by a cooler spell.

This warming-up process suffered several temporary setbacks as short, cool spells occurred which disrupted the overall momentum.

Former Mayor Andrew Young had, indeed, prayed hard for a cool spell.

The weather had turned warin, after a brief cool spell that foreshadowed winter.

Short cool spells vary with the Indian Summer that can last for weeks on end.

Instead of the cool spell that should have followed the storm, there was a foretaste of summer in the air.

The cool spell and a healthy dose of rainy days have offered a range of benefits.

With each warm spell tundra and forest edges have moved north, only to be forced south again during cooler spells.