Residents along the Front Range and Eastern Plains could wake up to the first coat of frost of the season today, nearly three weeks ahead of schedule, according to the National Weather Service.
Rain Wednesday evening ushered in an icy chill that pushed temperatures to the low 30s in areas below 6,000 feet, including Denver and 13 other Colorado counties.
Patchy frost is expected between 3 a.m. and 8 a.m., possibly putting a bite on lingering backyard gardens and late-summer flowers, the National Weather Service warned.
“Sensitive outdoor plants may be killed if left uncovered,” forecasters said in an advisory.
The frost advisory is in effect for parts of Denver, Adams, Boulder, Jefferson, Broomfield, Douglas, Arapahoe, Elbert, Morgan, Lincoln, Logan, Washington, Phillips and Sedgwick counties.
A freeze warning is in effect until 9 a.m. today for the Upper Gunnison River Valley, where temperatures are expected to fall into the upper 20s before morning.
The average date for the first freeze in Denver is Oct. 7, according to weather records.
A quick warmup is expected though, with an afternoon high to 78 degrees in Denver. The average high for the date is 77 degrees with an average low of 47 degrees, according to weather records.
Highs in the low 80s under sunny skies are expected in Denver this weekend, while much of high country peaks out in low 60s, according to the National Weather Service.
