Alamosa, Colo. – Gardeners and farmers in the San Luis Valley should prepare for a sharp chill early Sunday as the National Weather Service issued a Frost Advisory from 3 a.m. to 9 a.m., with temperatures expected to dip as low as 33 to 36 degrees. Sensitive plants could be damaged if left uncovered.
According to the National Weather Service in Pueblo, clear skies and light winds overnight will allow temperatures to quickly fall near freezing, creating ideal conditions for frost to form. The advisory covers Alamosa, Monte Vista, and surrounding areas where agriculture and backyard gardens remain active in mid-September.
Drivers across the high valley may also encounter patchy frost on windshields and rural roadways during the early morning hours. Residents are urged to cover plants, bring potted vegetation indoors, and protect outdoor plumbing and irrigation systems.
Elsewhere in southern Colorado, cities like Pueblo, Trinidad, and La Junta will stay milder, with lows holding in the upper 40s to low 50s, keeping the frost threat confined to the higher valleys.
The advisory is expected to expire by mid-morning as the sun warms the region, but additional alerts are possible if clear, calm nights persist into early next week.
