Summer rainfall patterns in the Southeast & South Central U.S. (climate, temperature)

[ral31]

What are the factors behind the summer precipitation patterns of the Southeastern and South Central United States?

Most of the Southern U.S. gets plentiful rainfall in June. However, in July and August, there is a drop in rainfall in Texas as a high pressure ridge tends to build, but also areas to the east to a lesser degree such as north Louisiana, north Mississippi and Arkansas towards late summer. Eastern parts of the South and areas near the Gulf coast have more uniform high precipitation throughout the summer.

[ral31]

Some interesting maps that show percent of annual normal precipitation that falls in each month.
NADM Climatology Maps | North American Drought Monitor (NADM) | Temperature, Precipitation, and Drought | National Climatic Data Center (NCDC)

[CairoCanadian]

Interesting find. It seems to be Texas and the inland south especially, with the immediate east Gulf coast / Atlantic unaffected.

[cBach]

Yes, that area is quite dry in late summer with parched crack earth. The difference between Lake Charles, right on the coast, and Natchitoches, inland quite a bit is quite drastic in the summer. Natchitoches can be 105 and sunny without a cloud, whereas Lake Charles could be 85 and thunderstorms at the same time.

Here in Austin, May is quite wet but June begins the dry season and it continues until October. Here, however, humidity is much lower and it's a much more different landscape.