Scarce rainfall in June has left about a third of Texas in a drought, making some areas among the most severely dry in the country, officials said Friday.

Since July is historically a drier month than June, it will only take a few more weeks of dry weather to cause rapidly deteriorating conditions for some areas, state climatologist John Nielsen-Gammon said.

"The lack of rainfall comes at a critical time of the year," said Nielsen-Gammon, also a professor of meteorology at Texas A&M University.

Nielson-Gammon said numbers show that many cities received less than half the amount of rain that normally falls in the spring. Houston, he said, had its driest June in 100 years.

Travis Miller of the Texas Cooperative Extension program said the drought could mean trouble for farmers, who may soon be fighting aflatoxins that produce mold on crops.

"The lack of rain places corn under stress and makes plants vulnerable for the development of aflatoxins," Miller said. "(Aflatoxins) restrict the usage of corn and greatly lower prices paid to farmers."

Nielsen-Gammon said at least 99 Texas counties have enacted burn bans because of the dry weather.