Frost/Freeze in Animas River Basin, Colorado

The minimum temperature recorded at the KDRO ASOS at Durango-La Plata County Airport was 27F, while the minimum temperature recorded at any of the 17 available sensors was 23F. All 17 available sensors recorded at least 3 hours of temperatures at or below 32F, with an average duration of 9.5 hours. The maximum duration was 11 hours and the minimum was 7. Therefore this event qualified as a standard freeze. Temperatures at or below 28F were recorded for, on average, 4 hours, with a maximum duration of 8 hours and a minimum of 1 hour. Therefore this event also qualifies as a hard freeze event. No reports of crop damages or losses were received.

Once the growing season is underway, freeze products are needed even when a widespread freeze or hard freeze has occurred as recently as the night before, if conditions warrant. Such was the case on the night of the 19th to the 20th, as continued cold air advection behind a departing low pressure combined with good radiational cooling conditions to lead to widespread temperatures at or below 32F in the lower valleys.