“Due to weather ... go f*** yourself,” a sign on the busy intersection at Montrose and Westheimer greeted drivers on Monday morning.
Mizanur Rahman, the founding editor of local news site Houston Landing, said he noticed the profanity on his way to work and posted pictures to X/Twitter.
“Well this made my commute to our office this morning rather entertaining,” Mr Rahman wrote.
The profanity-laced sign remained unchanged when Mr Rahman returned past it hours later, he said in a follow-up post.
Like much of the United States, Houston has been baking in a record heatwave this summer that saw high temperatures exceed 100F (37.7C) for months on end.
The city set a new record high temperature of 109F (42.7C) in August.
Temperatures on Monday dipped into the 70sF, the lowest in months, providing some relief for the city of 2.3 million residents.
The social media post was viewed more than 230,000 times and attracted a flurry of humorous responses.
“I have muttered that second billboard to myself soooooo many times in Houston traffic,” one poster wrote.
A Houston Public Works spokesperson told the Houston Chronicle that the sign did not belong to them, and was controlled by a locked box attached to the sign. It has since been switched off by a city inspector.
It’s unclear whether the hack was a protest or simply a joke.
In June, Texas Governor Greg Abbott signed a law that ended compulsory water breaks for outdoor workers.
The sweeping new “Death Star” bill overrode the ability of local government to set progressive laws, including providing sick pay and providing protection for tenants facing eviction.
Last month, a judge ruled the bill was unconstitutional.
The climate crisis, fuelled by manmade use of fossil fuels, exposed almost half of the world’s population to extreme heat between June and August, a recent study showed.