Alert archive / Colorado / Freeze Warnings in 2025

Freeze Warning 2, NWS Denver/Boulder, CO

October 20, 202510 counties in Colorado

NWS Denver/Boulder, CO issued this freeze warning at Oct 20, 2025, 2:06 AM MDT for 10 counties in Colorado. It took effect at Oct 21, 2025, 12:00 AM MDT. It was in force for 8 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 20, 2025, 2:06 AM MDT (08:06 UTC)
In effect from: Oct 21, 2025, 12:00 AM MDT
Expired: Oct 21, 2025, 8:00 AM MDT
In force: 8 hr
Issued by: NWS Denver/Boulder, CO

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Jefferson County, CO, Larimer County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 25 km from the middle of the area, began a volume at 08:05 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 00:00Z, 8.1 hours before the alert went out and 327 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2804 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 186 m²/s²
0-3 km storm-relative helicity: 359 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this freeze warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this freeze warning went out at Oct 19, 11:47 PM MDT, 2 hours 19 minutes earlier.

Area forecast discussion, Oct 19, 11:47 PM MDT, 2 hours 19 minutes before

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The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 20, 5:37 AM MDT	High Wind Warning	BOU	Larimer, Morgan, Washington, Weld	5 hr

Nearby

Freeze Warnings in Colorado, 2025 Every freeze warning in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.