Another thing, Trillium Covert and Madrono Ranch were happily situated in a narrow thermal belt
, so that in the frosty mornings of winter the temperature was always several degrees higher than in the rest of the valley.
The mightiest volcano in this thermal belt
last exploded about 40 years after Pompeii was engulfed.
Because hillsides are not quite as cold in winter as the lower ground beneath them, they're called thermal belts
This zone of Central Valley thermal belts
has hot, sunny summers--essential for sweet fruit--but seldom gets heavy freezes.