The Siren Board

Most of the cities in the Houston suburbs test weekly with a couple of outliers:
Baytown- Wednesdays at 9 am
Texas City, & Bayou Vista- Wednesdays at 12 noon
University of Houston- 1st Wednesdays at 1 pm
Mont Belvieu- 1st Wednesdays at 4 pm with quiet tests every other Wed.
Pasadena- 1st Thursdays at 6 pm (Will start testing on Saturdays at 12 noon in May of 2019)
Friendswood- 1st Fridays at 12 noon
La Porte & Deer Park- Saturdays at 12 noon

Rice University has a small system of ATI HPSS-16 sirens but testing times are unknown

Galena Park has three Federal Signal 2001-SRN's but I am unsure on when they are tested.

Katy had a system of four Sentry 40V2T's before the city took them offline

Wichita Falls, Electra, Burkburnett, Archer City and Quanah test their sirens on the first Monday at noon. Iowa park, the last Friday of the month around 10 or 11. Sirens in this area include Thunderbolt 1000s and 1003s, SD10s, 2T22s, Federal 2001s, Federal Eclipse, Sentrys, and Whelens.