Zanthan Gardens
Weblog of a Central Austin Garden

This post was published originally on November 23, 2006. It’s been updated to include data from Winter 2006 to Spring 2010.
Tamara up in Plano and I both have been eyeing these gorgeous October days with suspicion. It is after all November. As memory serves, Thanksgiving week is cursed with ice storms to frustrate all the Austinites trying to make it back to their parents in DFW or Houston or Lubbock. (Austin has a population of about 60,000 students from 5 universities. Many, like me, stay after graduation and make a trek out of town for holidays. The Friday after Thanksgiving, downtown Austin is so void of people you’d think the rapture had hit, except that this is Austin and if the rapture hit we probably wouldn’t notice anyone missing.)

But does memory serve? or does it distort? I decided to troll though my garden journal and the KXAN Weather Diary for data. These go back only to 1997 not enough to make out any trends except the already known: Austin’s weather is unpredictable. We get 8 to 15 days of freezing weather but rarely at one time. The all-time record low? -1F in February 1899. I’m glad I didn’t live through that!

Typically we have a week of bad weather (yes, Kathy, just one) in mid-January or early February. But in 1998, the only pre-spring freeze was on March 10th. The peach growers weren’t too happy. We also usually have a winter storm sometime in December.

A lot of our freeze dates are just light frosts with temperatures brushing 32F. Our hard freezes (28F or below) are the result of arctic fronts. Even then, freezing temperatures last only three or four days. It’s unusual, even in our worst winters, for the daily high temperature to stay below freezing. (This happened in 1997 on January 13th and 14th). The record for consecutive hours below freezing at Austin was 140 hours from December 21-27, 1983. The water main on South 1st St near my apartment broke. Also the rubber connectors on the fuel line of my Spitfire cracked and a month later my car burst into flames as I was driving down Anderson Lane with my kid in the car seat.

Due to the general mildness of our winters, any time Austin does get freezing rain or sleet, the town shuts down. Schools and stores close. Hundreds of people get into traffic accidents. Airline flights are delayed. And the power goes out. Northerners are agog. The answer is simple. For a once-a-year winter storm, why invest in infrastructure? So our cars don’t have chains or snow tires.

Our ground never freezes. Our plants don’t go dormant. A bad freeze is often preceded or followed by record high temperatures.

Last Spring Freeze

Looking back to 1997, the last freeze before spring in Austin was March 10th, 1998.

If it’s 81F in January, wouldn’t you plant out your tomatoes? That’s what happened in 2002. Then March brought the coldest mornings of the year (and two of the colder days in this little study) when it got down to 24F on March 3rd and 4th.

First Fall Freeze

As for the answer to the question that started this research–When should Austinites expect our first frost? Anytime now.

A Summary of Winter in Austin Over the Last 14 Years

Note: In 1999 the weather service begins reports from both Camp Mabry and the airport (ABIA). I stuck with the Camp Mabry statistics to be consistent. The weather in my garden is closer to Camp Mabry’s than ABIA’s. ABIA is often 3-5 degrees colder than downtown. As I’ve learned from my gardening friends, your results may vary. One part of Austin may freeze and another not. Even within your yard, the microclimate varies.

1997: 16 days freezing temperatures.

Austin gets all our winter in one week and then have ten frost-free months. The coldest part of winter was a week in January from 1/7 to 1/14: 1/7 (32F); 1/9 (30F); 1/10 (30F); 1/11 (25F); 1/12 (24F); 1/13 (23F) high (27F); 1/14 (26F) high (32F); 1/15 (30F); 1/17 (26F). 1/28 (27F); 1/29 (29F). Not another freeze until December: 12/13 (29F) and a few snow flurries; 12/15 (32F); 12/28(32F).

1998: 3 days freezing temperatures.

This is the kind of winter that lulls gardeners into putting out the tomato plants too early and peach trees into bloom. The first freeze of 1998 was in March, 3/10. It was also the last freeze until December when we got our one week of winter 12/21 and 12/26. The temperature dropped from 74 degrees at 5pm to 38 degrees at 8pm and continued to drop. The weather service notes, “Freezing drizzle creates early morning chaos. All area bridges and elevated roads become iced over. 400+ Austin accidents. 64 car pileup on I-35 at 290 kills 2. 1 other fatality in area, 16 total in Texas ice-related accidents. Many businesses open late or close. Occasional freezing drizzle continues through evening. A few snow flurries reported at airport. Winter storm warning thought tomorrow A.M. Christmas travelers stranded as many flights into and out of Robert Mueller Airport are delayed and cancelled, mainly due to delays elsewhere, including DFW.” The lowest temperature of this storm was 25F on 12/26. The next day the high was 72F.

1999: 5 days freezing temperatures.

Cold the first week of January. For three days in a row the nighttime lows dip below freezing with the lowest temperature of 27F on 1/5 and then again on 1/10. However, we also have a record high of 81 on 1/17. (The tulips hate that!) The only other freezing day of the year is 12/6 when it drops to 32F.

2000: 11 days freezing temperatures.

Cold the first week of January: 32F on 1/4 and 27F on 1/5. Next freeze on 12/7 (31F). A couple of days later on 12/11 an arctic front moves in. 12/11 has a low of 31F. 12/12 has a high of 31F and the low for the year of 26F. Icy conditions result in more than 300 auto accidents. It continues to be really nasty on 12/13 “90,000 lose power in Austin as heavy freezing rain downs trees and powerlines. More than 288,000 without power statewide, mainly in Dallas-Fort Worth, Tyler-Longview, Waco-Killeen and Austin areas. Record daily rainfall at ABIA. It dips to 28F on 12/17; 31F on 12/22; 32F on 12/27 and 12/28 and 28F on 12/30. December was an unusually cold end to a year of warmer than average months through November.

2001: 12 days freezing temperatures.

The cold weather continues into January of the new year. 1/1 (31F), 1/2 (30F), 1/3 (32F) 1/4 (32F). We are teased with a chance of snow on 1/19 but it is much too warm. When the front moves through leaving clear skies it drops to 27F (1/20). February has two freeze dates: 2/3 (32F) and 2/17 (32F). Then Austin’s frost-free until November: 11/28 (31F) and 11/29 (30F). December is rainy and fairly mild: 12/10 (32F), 12/24 (32F) and 12/31 (32F).

2002: 15 days freezing temperatures.

1/2 (30F); 1/3 (26F); 1/4 (28F); 1/13 (32F); 1/15 (31F) and then a record high of 81F on 1/29. A colder February than in recent memory: 2/2 (32F); 2/7 (30); 2/26 (30); 2/27 (25F); 2/28 (30F). And a cold start to March: 3/2 (29F); followed by the coldest morning of the winter 3/3 (24F) and 3/4 (24F); 3/5 (31F). That’s it until Christmas: 12/25 (32F).

2003: 14 days freezing temperatures.

In 1999 Austin had a record high of 81 on 1/17. Four years later, we get our first freeze on 1/17 (29F), followed by freezes on 1/18 (27F) and 1/19 (28F), followed by a record high on 1/21 (82F). Two days later it’s cold again: 1/23 (30F); 1/24 (26F). 2/17 (31F). Temperatures drop from 78F on 2/23 to 26F on 2/24. Camp Mabry report .6 inch of snow! Then the usual power outages, school closings and traffic tie-ups on 2/25 (24F) which posts a high of 30F. 2/26 (29F). No more freezes until November: 11/29 (30F). December: 12/6 (31F); 12/14 (31F); 12/20 (32F); 12/30 (30F).

Scenes from late February’s winter storm.

2004: 14 days freezing temperatures.

January: 1/6 (29F); 1/20 (32F); 1/27 (29F); 1/28 (30F). February: 2/7 (30F). December: 12/1 (31F); 12/14 (31F); 12/15 (25F); 12/22 (32F); 12/23 (24F); 12/24 (26F). A historic Christmas Eve snowstorm drops snow to the north of us and 12″ of snow to the southeast of us and ZERO snow in Austin. I have never had a white Christmas. 12/25 (25F); 12/26 (27F); 12/27 (31F). We began the year with a high of 74F and ended it on a high of 78F.

2005: 9 days freezing temperatures.

January: 1/16 (30F); 1/17 (29F); 1/23 (30F); 1/24 (32F). November starts with highs of 88F on 11/7 and 11/8 before our first freeze on 11/17 (31F). Then it’s back to record highs of 87F on 11/23. I think this is when I gave up gardening that year. And suddenly it’s winter: 12/6 (27F); 12/7 (25F) and freezing drizzle and hundreds of car accidents.; 12/8 (23F); 12/9 (27F).

2006: 7 days freezing temperatures.

February: 2/12 (29F); 2/13 (31F). High of 82F on 2/16 preceding an arctic front: 2/18 (28F); 2/19 (28F) which results in more than 400 accidents as freezing fog ices up bridges and overpasses.

December: 12/1 (29F); 12/4 (29F); 12/8 (31F).

2007: 16 days freezing temperatures.

January: 1/15 (29F); 1/16 (29F); 1/17 (29F); 1/18 (32F); 1/29 (31F). A high of 81 on 1/5 is followed by some of our nastiest cold weather of the year. In the middle of a nasty 4-day storm, Austin has a rare day (1/16) where the temperature never gets above freezing. The low was 29F and the high was 31F. Bonus. Snow!

Austinites were excited by a dusting of snow.

February: 2/3 (28F); 2/4 (32); 2/14 (30F); 2/15 (29F); 2/16 (24F).

December: 12/16 (30F); 12/17 (30F); 12/23 (28F); 12/24 (29F); 12/27 (30F); 12/29 (31F). What’s a gardener to do? December 2007 had four days in the 80s and 6 days at 32 or below.

2008: 12 days freezing temperatures.

January: 1/2 (30F); 1/3 (29F); 1/17 (32F); 1/19 (30F); 1/20 (25F); 1/30 (32F).
February: 2/1 (28F); 2/27 (31F). This month opens with a hard freeze but then temperatures soar to 92F on February 25th. Seven other high temperature readings this month were in the 80s.
December: 12/6 (29F); 12/15 (31F); 12/16 (29F); 12/22 (28F).

2009: 13 days freezing temperatures.

January: 1/12 (30F); 1/14 (30F); 1/21 (31F); 1/27 (32F); 1/28 (28F); 1/29 (28F). Two days of hard freeze on the 28th and 29th but by the 31st the high has rebounded to 71F.
February: 2/3 (30F). We’re still in the drought and like 2008, this February starts with one cold day but ends with a temperature in the 90s: 91F on 2/27.
It starts raining in September 2009 and we have a much wetter winter than in the previous two years. The cloud cover and the soil moisture keeps the temperatures more constant and cooler. Winter begins with a hard freeze causing many trees to drop all their leaves in a few hours.
December: 12/4 (29F); 12/5 (25F); 12/9 (32F); 12/10 (31F); 12/25 (31F); 12/26 (28F).

2010: 17 days freezing temperatures in spring.

January 2010 brings the most miserable winter weather in most Austin gardeners’ memories. We hope never to see its equal in our lifetimes. Five hard freezes in a row and temperatures in the teens! The official Camp Mabry temperature dropped to 17F but it was lower at ABIA and in many of my friends’ gardens.
January: 1/2 (29F); 1/4 (32F); 1/5 (27F); 1/7 (28F); 1/8 (21F); 1/9 (17F); 1/10 (20F); 1/11 (27F); 1/29 (32F); 1/30 (30F); 1/31 (30F).
February: 2/13 (30F); 2/15 (32F); 2/16 (30F); 2/17 (30F); 2/24 (32F); 2/25 (32F).
December: 12/1 (32F)

We got a wonderful snowy day (but no freeze?) on February 23rd. The snow didn’t stick and alternated with rain, sometimes freezing and sometimes not.

Although two freeze warnings have been issued for Austin, we’re still waiting for our first freeze of this winter.

Update: December 1, 2010

This morning Camp Mabry registered its first freeze of winter 2010/11. Many Austin gardens already experienced light frost damage from cold temperatures last week.