100% CORRECT! Due to the prevailing winds from the South West, most of the rain in Texas is a function of water and air temps in the Pacific Ocean. The coastal regions of Texas do get rain as a function of the Gulf of Mexico. However Texas as a whole is dependent on Pacific Moisture.
La Nina has cooled the Pacific. A result of this is less moisture in the airflow from the prevailing winds in Texas. Less moisture means less rain and less cloud cover. Less cloud cover means very high day time temperatures and moderately higher night time temps dependent on the normal local cloud cover. If the local cloud cover in normal conditions is high, La Nina could actually cause night time temps to be moderately lower instead of higher.
When we have El Nino (high temps in the Pacific) life is good in Texas. When we have La Nina (low temps in the Pacific) the weather in Texas sucks. The weather pattern that caused the "Dust Bowl" was several years of La Nina. I hope we are not repeating this.