Since the South Plains is largely rural, crime is virtually nonexistent outside of the major cities. The weather, however, does require some vigilance, as the region often experiences the widest weather extremes in the state. South Plains winters can be surprisingly brisk, and the areas at the far north end can receive significant snowfall during the winter months. Conversely, summertime high temperatures routinely top 100ºF 38ºC. Pack and dress accordingly. Also, during the spring months, dust storms are quite frequent and while these are not necessarily "dangerous", they can be frightening to those who have never experienced one.
The Llano Estacado is in Tornado Alley. Check the Tornado safety page for information.
talk
Outside of Lubbock, the South Plains is one of the places in Texas where the "Texas Accent" is still quite prevalent. An outsider or foreign traveler may have to ask a local to repeat themselves a time or two to understand what they are saying due to local dialect and slang, but generally they do not mind. It is not suggested, however, to kid them about it; to the people of the South Plains like all Texans the way they speak is a strong element of their sense of self and is a large part of who they are, and they are proud of it.
Spanish is also spoken by a sizeable minority on the Llano Estacado, and while it would be unusual for an outsider to encounter a situation where nobody around speaks English, at least a rudimentary grasp of Spanish is certainly helpful.