After a cold front passed through the area on January 15th, surface high pressure settled in behind the front which ushered in drier air and clear skies. This allowed for temperatures to drop below freezing on the morning of January 16th. Some instances of frost were also observed in parts of the Rio Grande Valley, and likely across some ranch communities as well.

Frost/Freeze in NORTHERN HIDALGO COUNTY, TEXAS
From 16-JAN-21 00:45:00 to 16-JAN-21 05:45:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Temperatures fell below freezing around 12:45 AM and remained below freezing until 5:45 AM. Low temperatures fell into the upper 20s and lower 30s across the area. A minimum temperature of 27 degrees was observed at the Linn-San Manuel RAWS site.

Frost/Freeze in STARR, TEXAS
From 16-JAN-21 01:00:00 to 16-JAN-21 09:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Temperatures fell below freezing around 1:00 AM and remained below freezing until 9:00 AM. Low temperatures ranged from the middle 20s to the lower 30s across the area. A minimum temperature of 26 degrees was observed at the Falcon Lake RAWS site. The Rancho Los Comitas COOP site also observed a low of 31 degrees.

Frost/Freeze in BROOKS, TEXAS
From 16-JAN-21 02:30:00 to 16-JAN-21 08:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Temperatures fell below freezing around 2:30 AM and remained below freezing until 8:30 AM. Low temperatures fell into the lower 30s across the area. A minimum temperature of 30 degrees was observed at the Calosa 1 Mesonite site. Brooks County Airport also observed a low of 31 degrees.

Frost/Freeze in ZAPATA, TEXAS
From 16-JAN-21 05:15:00 to 16-JAN-21 08:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Temperatures fell below freezing around 5:15 AM and remained below freezing until 8:00 AM. Low temperatures fell into the lower 30s across the area. A minimum temperature of 30 degrees was observed at the Zapata airport.

Frost/Freeze in INLAND KENEDY COUNTY, TEXAS
From 16-JAN-21 06:30:00 to 16-JAN-21 08:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Temperatures fell below freezing around 6:30 AM and remained below freezing until 8:30 AM. Low temperatures ranged from the middle 20s to lower 30s across the area. A minimum temperature of 26 degrees was observed at the SARITA Union Pacific Railroad Mesonet. The Armstrong COOP site also observed a low temperature of 30 degrees.

Frost/Freeze in CAMERON, TEXAS
From 16-JAN-21 05:00:00 to 16-JAN-21 08:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Temperatures fell into the middle and lower 30s shortly before sunrise on the 16th. This allowed for some instances of frost to develop. Most frost was observed on vegetation or on rooftops, via both in-office COOP observations and social media reports.

Frost/Freeze in SOUTHERN HIDALGO COUNTY, TEXAS
From 16-JAN-21 05:00:00 to 16-JAN-21 08:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Temperatures fell into the middle and lower 30s shortly before sunrise on the 16th. This allowed for some instances of frost to develop. Most frost was observed on vegetation per a report received via social media.