This is from the AP:

An estimated 60 percent, or 2 million of the 3.3 million total voters, cast their ballots early, Texas Secretary of State Phil Wilson said Monday. The estimate is based on the slightly more than 1.2 million who voted in the 15 most populous counties during a 10-day period that ended Feb. 29.

“Texas is well on its way to a new record for turnout in a primary election,” Wilson said.

…

The Secretary of State’s Office tally for the 15 most populous counties showed that 890,188, or 11.39 percent of registered voters in those counties, voted early in the Democratic primary — more than the Texas Democratic Party has seen in the past two presidential primaries statewide for early and Election Day voting.

Harris, Dallas and Bexar counties had the largest numbers of early Democratic voters, with 403,197 ballots cast in person and by mail in those three counties covering Houston, Dallas and San Antonio.

The biggest percentage turnout among Democrats was Hidalgo County, in the predominantly Hispanic Rio Grande Valley, where 18 percent of registered voters cast ballots.

On the Republican side, 303,338, or 3.88 percent, of registered voters in the 15 biggest counties cast early ballots. The largest number was in Harris County, with 64,631 early GOP voters; the largest percentage of registered voters was 7.66 percent in Montgomery County north of Houston.