On the morning of September 13, 2008, the eye of Hurricane Ike approached the Texas coast near Galveston Bay, making landfall at 2:10 a.m. CDT over the east end of Galveston Island. People in low-lying areas who had not heeded evacuation orders, in single-family one- or two-story homes, were warned by the weather service that they may "face certain death" from the overnight storm surge, a statement that turned out to be true for some who refused to evacuate.

In regional Texas towns, electrical power began failing before 8 p.m. CDT, leaving millions without power (estimates range from 2.8 million to 4.5 million customers).

Flood waters begin to rise in a neighborhood of Galveston, Texas.  In Galveston, by 4 p.m. CDT (2100 UTC) on September 12, the rising storm surge began overtopping the 17-ft (5.2 m) Galveston Seawall, which faces the Gulf of Mexico; waves had been crashing along the seawall earlier, from 9 a.m. CDT.  Although Seawall Boulevard is elevated above the shoreline, many areas of town slope down behind the seawall to the lower elevation of Galveston Island.

Even though there were advance evacuation plans, Mary Jo Naschke, spokesperson for the city of Galveston, estimated that (as of Friday morning) a quarter of the city's residents paid no attention to calls for them to evacuate, despite predictions that most of Galveston Island would suffer heavy flooding storm tide. By 6 p.m. Friday night, estimates varied as to how many of the 58,000 residents remained, but the figures of remaining residents were in the thousands.  Widespread flooding included downtown Galveston: six ft (2 m) deep inside the Galveston County Courthouse, and the University of Texas Medical Branch at Galveston was flooded. Tourist attractions on the island suffered various degreed of damage. The Lone Star Flight Museum suffered massive damage as the storm surge washed though the airport and hangars with about 8 feet of water, and the recently completed Schlitterbahn Water Park is still closed as of November; however, Moody Gardens was built with storms in mind and was able to withstand the worst of the storm.

In Houston, windows also broke in downtown buildings such as the 75-story JP Morgan Chase Tower, and Reliant Stadium was damaged. Also as a result of the high wind and eye wall that passed directly through the city, power outages were a major problem, as some residents were still without electricity over two weeks after landfall. Some parts of Houston were not expected to have power until November 1. Luckily, since the storm system moved rapidly and did not linger over Houston, flooding wasn't a major problem for most of the city, as it normally is as a result of the geography.  Due to the damage to the stadium, the Houston Texans' game with the Baltimore Ravens, originally scheduled for September 14, was pushed back to November 9.  Hurricane Ike affected the Houston Astros' late dash for Major League Baseball's playoffs, postponing Friday, Saturday, and Sunday's games against the Chicago Cubs.  Two of the games were moved to Milwaukee's Miller Park and were played Sunday September 14 and Monday September 15.  The final game was tentatively scheduled for Monday September 29 in Houston. The Astros were eliminated from playoff contention on September 26 and the game was officially canceled as it would not affect post season standings.

On Bolivar Peninsula, Texas dozens of people were rescued as flood waters exceeded 12 feet (3.7 m) above sea level in advance of the hurricane. The peninsula bore the brunt of Ike's right-front quadrant, historically the worst part of a hurricane, and experienced catastrophic damage with the worst being between Rollover Pass and Gilchrist, Texas - west of High Island. Media estimates of lost homes exceed 80% and could top 95%.  A large number of people who did not evacuate in advance of the storm remain unaccounted for.

The Southeast Texas community of Bridge City on Sabine Lake and areas of nearby Orange were inundated by the storm surge. Bridge City mayor Kirk Roccaforte estimated that only about 14 (later updated to around two dozen) homes in the city were unaffected by the surge.

NASA's Johnson Space Center suffered minor roof damage to Mission Control and minor cosmetic damage to some of its other buildings. NASA's operations at Ellington Field also sustained roof and awning damage.

As a historical comparison, on September 8, 1900 the Galveston Hurricane of 1900 landed along a path similar to Ike's, bringing with it a storm surge that inundated most of Galveston Island, then Texas' largest city and a major U.S. port. As a result, much of the city was destroyed and at least 6,000 people were killed in a few hours. Engineers subsequently increased the average elevation of the island by 4 feet (1 m) and constructed a 17-foot (5 m) seawall to block incoming waves.