The deaths newly tallied by the Texas health department lifted the toll from 151 to 210, most from exposure to sometimes-subzero temperatures. Some deaths were blamed on carbon monoxide poisoning as freezing Texans sought warmth from cars and outdoor grills.
The count remains preliminary and may change as more deaths are confirmed, the department said.
The county with the highest death toll was Harris, where Houston is situated, with 43 deaths. Travis county, where Austin holds most of its population, had 28 deaths. Dallas county reported 20 deaths.
An initial 15 March report put the toll at 57 deaths. The toll was raised to 111 on 25 March, 125 on 6 April and 151 on 28 April.
The collapse of the power grid managed by the Electric Reliability Council of Texas (Ercot) has made electric reliability in Texas, a Republican-run state, a key political question.
In early June, Governor Gregg Abbott declared that state lawmakers had fixed the problem during its regular session that had just adjourned.
Since then, two conservation alerts issued by Ercot during temperate weather prompted renewed questions. Abbott ordered new measures from a public utility commission he appointed and which oversees Ercot.