Melania Trump, 47, chose the green cap in solidarity with the storm-ravaged state.
The rest of her outfit was also casual, and the First Lady chose a loose fitting denim shirt, which she wore with the collar popped.
She paired this with dark green denim cutoff jeans, which had a skinny fit.
A pair of darn green Converse trainers completed the look.
Shading her eyes from the sun, Melania opted for a pair of large mirrored aviators.
Donald Trump, 71, and Melania flew in for a short visit to Texas, meeting those who had been affected by Hurricane Harvey.
Melania sat with families who had lost their homes, playing games with children.
The couple then handed out food to other victims of the storms.
Melania had changed into her outfit on the flight to Texas, as she left the White House in a completely different look.
The First Lady wore a brown belted dress as she made her way to the plane with Donald Trump.
The dress was buttoned down the front and featured two pockets on the top half.
Although very fitted – showing off every curve – Melania’s dress had a coservative cut and came to her knee and had long sleeves.
Controversially, she paired the dress with a pair of snakeskin stiletto court shoes, despite facing intense criticism for wearing black stiletto shoes for her first visit to Texas last week.
Even though it was raining heavily, Melania completed her look with a pair of tortoiseshell sunglasses.
She wore her hair in lose waves over her shoulders, and cuddled up to Donald as they sought shelter from the poor weather under a black umbrella.
Melania didn’t carry a handbag or wear a jacket as she walked to the waiting plane.