This is about as far south as you can get and stay in Mainland USA. (Key West is an island, after all)
At 1053AM, CT, Brownsville was reporting a temperature of 82 with sunny skies. There was a swath of very dry air over far southern Texas as a ridge of high pressure built into the lower Mississippi Valley.
The ridge is inducing an easterly flow off the Gulf which will inevitably produce some low level clouds and some fog in the deep south of Texas, but the system is expected to break down to a light pressure gradient over the next 48 hours, which will prevent any precipitation from forming over Brownsville.
Tomorrow – Mostly sunny, High 87, Low 62
Thursday – Sunny, High 88, Low 65
TWC: Tomorrow – Sunny High 88, Low 62
Thursday – Sunny High 87, Low 64
AW: Tomorrow – Partly sunny High 86, Low 60
Thursday – Mostly sunny and breezy High 87, Low 64
NWS: Tomorrow – Sunny, High 86, Low 62
Thursday – Sunny, High 87, Low 65
WB: Tomorrow – Sunny, High 87, Low 71
Thursday – Sunny in the morning then becoming partly cloudy. High 87, Low 63