This time of year, my inbox starts filling up with emails and DMs asking the same question: Are we finally done with freezing temperatures in Houston?
I get it. Everyone’s ready to break out the shovels and plant those gorgeous tropicals that love our Texas heat. But no one wants to drop good money on plants that could get wiped out by one last dip to 32°.
Before we answer the big question, let’s zoom out for a little perspective. Looking back over the last six years, we’ve only had one March freeze. That was back on March 12th and 13th of 2022, when temperatures fell to 32°.
So… March freezes are possible but they’re definitely not the norm.
Climatology is on our side here. On average, Houston’s last freeze happens around Feb. 15th and that’s based on records going all the way back to 1889.
What’s interesting is if you zoom in on just the last 30 years, that date one day later. Feb. 16th.
Down at Hobby Airport, the average last freeze over the past 30 years is Jan. 26th, almost three weeks earlier. And the reason? Those roughly 25 miles between Hobby and Bush make a big difference when cold air is involved.
In other words, location matters; the closer you are to the coast, the less likely you’ll get a freeze in March.
The danger with averages is that they can lull you into a false sense of security. Most years behave nicely… until one doesn’t. Like 2022, when we managed to sneak in a freeze in mid-March and ruin a few planting plans.
And then there’s the extreme outlier that still makes gardeners shudder. 1973. Can you believe the latest freeze ever recorded in Houston happened on April 10th, 1973?
That’s the reminder: averages are helpful, but Houston weather doesn’t always stick to the script.
I don’t need to tell you our climate today is much warmer than it was back in the 1970s. That’s why I don’t expect Houston to see another freeze as late as April again.
Take a look at the graphic below from Climate Central. Since 1970, Houston has averaged 20 fewer freezing nights. That’s a big shift and it lines up with what we’ve all felt over the years: winters just aren’t as cold or as long as they used to be.
I think the graphic below is fascinating. It shows the first and last freezing dates in Houston going all the way back to 1890. The early 1970s really jump off the page.
What the graphic doesn’t show, though, is just how many freezing days we racked up in the 70s and 80s. Those were legitimately cold decades around here. Freezes were more frequent, winters were longer, and cold air had staying power.
Since then, the trend has been pretty clear: fewer freezes overall, the first freeze coming later in the year, and the last freeze ending earlier in the season. In other words, winter’s window has been shrinking, and Houston has been warming right along with it.
So… should you plant? Here’s my general rule for Houston: wait until spring break shows up in the forecast.
Strong cold fronts can still sneak in this time of year. Right now, there are no freezes showing up in the 10-day forecast, but take a look at Tuesday’s forecast below. Our weekend cold front knocks temperatures down into the 40s here in Houston, while parts of the southeastern U.S. drop to freezing. With slightly different steering, that cold air could’ve easily been aimed at us.
The good news? Spring break does show up in the 10-day forecast on March 1st. That’s my green light.
So, if you’ve been itching to plant, you’re almost there. Just a little patience and then… happy planting.