5 biggest weather events in San Antonio area in 2021

The year was headlined by record-breaking cold weather in February

It’s only fitting that we end the year on such a warm note, after starting the year with some of the coldest temperatures South Texas has seen in decades.

Read more stories wrapping 2021 here.

It’s only fitting that we end the year on such a warm note, after starting the year with some of the coldest temperatures South Texas has seen in decades. Wild swings in temperatures fueled severe storms, set snowfall records, and produced a hailstone in Hondo the size of a melon. It feels as though we use the cliché every year by saying “this year was a memorable one” — but this time we REALLY mean it! Here’s a look at 2021′s top five weather events, as ranked by the KSAT Weather team:

#5: May 3rd San Antonio Hailstorm

Folks who live in and around downtown San Antonio remember this event. It arrived just days after a huge hailstorm in Medina County (the one with the melon-sized hail). In this event, a splitting supercell made its way across San Antonio’s west side, across downtown, through China Grove, and all the way to Seguin. It dropped massive hail, up to the size of baseballs, along the way. KSAT Weather received numerous pictures of the hail and widespread damage.

A variety of large hail stones which fell in St. Hedwig May 3, 2021. Sent in by KSAT Connect User jdb2008 (Copyright 2021 by KSAT - All rights reserved.)
Radar indicated hail sizes from May 3, 2021 (Copyright 2021 by KSAT - All rights reserved.)
Julian sent this in, showing damage to the windshield of his car.

#4: Snow (four days worth!)

This isn’t the last time we’ll talk about snow and cold in the countdown. It’s also something I never thought I’d write. San Antonio received measurable snow on four separate calendar days! As far as we can tell, that’s the first time in history that’s happened. However, it should be noted that in 1951 we received 0.4″ on Jan. 29, a trace on Jan. 30, 0.5″ on Jan. 31, and 0.4″ on Feb. 14. This go-round, we got a dusting (.2″) on January 10th, followed by three days of snow during our big freeze on February 14th (1.2″), 15th (2.5″), and 18th (2.5″). In total, we received more than 6″ this winter!

Residents, visitors in awe of The Alamo covered in snow

#3: Flooding (Tie) July 6th and October 13th

Number three is a tie between two memorable floods, both of which resulted in property damage. Sadly the latter also caused two deaths. The flood on July 6th began in the morning hours, with a band of storms producing high rainfall rates over San Antonio’s northwest side. All said and done, nearly 10 inches of rain fell over the Leon Valley area and funneled into Leon Creek. The creek would rise quickly, flooding homes. Leon Creek at I-35 reached its fourth-highest level ever recorded at that site. I-35 was shut down for a time and some residents near the creek had to be evacuated. Homes flooded near Heath Road and Grissom Road in San Antonio.

In the case of October 13th, tropical rainfall, aided from Pacific Hurricane Pamela, added up quickly. Creeks began to swell during the overnight hours, resulting in many high water rescues. As the heavy rain spread east of San Antonio, Martinez Creek near St. Hedwig began to rise. Sadly, two cars that tried to pass through the creek were swept away, resulting in the deaths of two people.

The National Weather Service issued a flood warning for Leon Creek until Wednesday morning.
An elementary student in the East Central Independent School District and a woman are missing after the vehicles they were traveling in were swept away by high water in St. Hedwig on Thursday morning.

#2: Largest hailstone in Texas history

This one is a mind-blowing record. I had to see it to believe it, but it happened, and the record books were rewritten. On April 28th, one of the most powerful supercells we’ve ever seen on local radar moved through Medina County. The storm put down a tornado just south of Hondo, which thankfully didn’t result in much damage. It was the storm’s hail core that caused the most damage. Inside that hail core, a melon-sized hailstone crashed to the earth! The stone was collected by a Medina County resident and stored in a freezer. It was later measured by the Insurance Institute for Business and Home Safety, using a 3-D scan. It was found to be 6.4″ in diameter! For now, it ranks as the largest hailstone in recorded history for the state of Texas.

An archived radar image from the severe thunderstorm that produced the massive hailstone near Hondo on April 28, 2021 (Copyright 2021 by KSAT - All rights reserved.)
IBHS's Ross Maiden prepares the massive hailstone for a 3-D scan

#1: The Big Freeze

I’m sure this comes as no surprise to anyone. February’s winter weather blast was record-setting not only for us but for a large chunk of the country. One could argue, however, that Texas took the hardest hit, especially considering our power grid couldn’t handle the extreme weather. There was a litany of records set, many of which will stand for a long, long time. It evolved from an exciting snow event to a dire situation for many, with the loss of power and water due to frozen pipes. Temperatures plunged into the single digits, wind chills went as low as -8° in San Antonio, and it remained sub-freezing for a near-record 107.5 hours! At the onset of the event, we also witnessed something never seen before: every inch of Texas was under a Winter Storm Warning. It’s an event that our children will grow up and tell their children about.

Snow day in San Antonio during February winter storm 2021. (KSAT 12)
Heavy snow piles up around KSAT studios (Copyright 2021 by KSAT - All rights reserved.)
San Antonio saw two rounds of accumulating snow. (Copyright 2021 by KSAT - All rights reserved.)

About the Author:

Justin Horne is a meteorologist and reporter for KSAT 12 News. When severe weather rolls through, Justin will hop in the KSAT 12 Storm Chaser to safely bring you the latest weather conditions from across South Texas. On top of delivering an accurate forecast, Justin often reports on one of his favorite topics: Texas history.