The morning of January 20th saw a cold front sweep through the Rio Grande Valley and Deep South Texas. As 1045 mb high moved out of Canada and pushed temperatures lower throughout the day on the 20th. An upper-level low moving overhead provided enough lift to allow widespread showers to form the night of the 20th into the morning of January 21st. All of this contributed to temperatures touching the freezing mark in numerous locations from Jim Hogg southeast through Cameron County.

Frost/Freeze in BROOKS, TEXAS
From 21-JAN-22 02:15:00 to 21-JAN-22 08:55:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Temperatures fell to freezing around 2:15 AM on January 21st and remained at or below freezing until 8:55 AM. Low temperatures fell into the lower 30s across the area. A minimum temperature of 31 degrees was observed at the Brooks County Airport (KBKS).

Frost/Freeze in JIM HOGG, TEXAS
From 21-JAN-22 04:15:00 to 21-JAN-22 06:15:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Temperatures fell to freezing around 4:15AM CST on January 21st and remained near freezing until 6:15AM CST. Low temperatures fell into the lower 30s across the area. A minimum temperature of 32 degrees was observed at the Jim Hogg County Airport (KHBV) in Hebbronville. A Mesowest station at Hellen Station also observed a low of 32.

Frost/Freeze in INLAND KENEDY COUNTY, TEXAS
From 21-JAN-22 01:16:00 to 21-JAN-22 08:47:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Temperatures fell to freezing around 1:16AM CST on January 21st and remained near freezing until 8:47AM CST. Low temperatures fell into the lower 30s across the area. A minimum temperature of 31 degrees was observed at the Union Pacific Railroad Station 8 miles south of Armstrong (UR074).

Frost/Freeze in NORTHERN HIDALGO COUNTY, TEXAS
From 21-JAN-22 02:15:00 to 21-JAN-22 08:55:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

The AWOS at the South Texas International Airport, 11 miles north-northeast of Edinburg, reported 32 degrees shortly after sunrise.  Proxy observations from western Willacy County and Brooks County support additional freezing conditions, most likely in northeast Hidalgo County, during this time.

Frost/Freeze in CAMERON, TEXAS
From 21-JAN-22 02:14:00 to 21-JAN-22 10:14:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Temperatures fell to freezing around 2:12AM CST on January 21st and remained at or below freezing until 10:14AM CST. Low temperatures fell into the upper 20s to lower 30s across the area. A minimum temperature of 29 degrees was observed at the Union Pacific Railroad Station 2 miles southeast of Sebastian (UR105) in extreme northern Cameron County. Elsewhere, Citizens Weather Observing Program locations recorded a low of 32 degrees in Los Fresnos, WFO Brownsville, and La Feria. The ASOS station at the Rio Grande Valley International Airport (KHRL) also briefly touched 32 degrees at 4:52AM CST.

Frost/Freeze in SOUTHERN HIDALGO COUNTY, TEXAS
From 21-JAN-22 03:45:00 to 21-JAN-22 05:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Temperatures fell to freezing around 3:45AM CST on January 21st and remained near freezing until 5:00AM CST. Low temperatures fell into the lower 30s across the area. A minimum temperature of 32 degrees was observed at the Mid Valley Airport (KTXW) in southeastern Hidalgo County. Elsewhere, NWS Cooperative observers recorded a low of 32 degrees in Edinburg and Santa Rosa. An AWS station in McAllen reported 32 degrees as well as the AWOS at the South Texas International Airport 11 miles north-northeast of Edinburg (KEBG).

Frost/Freeze in WILLACY, TEXAS
From 21-JAN-22 01:15:00 to 21-JAN-22 09:45:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Temperatures fell to freezing around 1:15AM CST on January 21st and remained near freezing until 9:45AM CST. Low temperatures fell into the lower 30s across the area. A minimum temperature of 31 degrees was observed by a Cooperative observer 1.8 miles West of Raymondville. A Union Pacific Railroad mesonet site 7.7 miles north of Raymondville also reported a minimum temperature of 31 degrees.