Drought continued to spread across Texas last week in what is being called the largest spread of drought in Texas in more than two years, the Texas Water Development Board said Monday in its weekly water report.

“Drought expanded rapidly in the last week and now covers 35 percent of the state,” Mark Wentzel, a hydrologist for the TWDB, said in the report. “All or large portions of 23 counties are now impacted by severe drought.”

Last week, the report found that 20 percent of the state was experiencing drought. By comparison, 14 percent of the state was in a drought this time last year.

Locally, the vast majority of Texoma and Northeast Texas is classified as being in a severe drought as of this latest report. All of Fannin and Grayson, which had previously remained drought-free until last week, were classified as in a severe drought this week, with all but the western edge of Cooke County also in major drought. To the south, all but the southern edge of Collin County is classified as a severe drought in the latest report.

This recent dry spell caps what has been a roller coaster year for the region. This year marked the wettest August on record for Grayson County, with the city of Sherman receiving more than 13 inches of rain for the month. One of the wettest months was followed by one of the driest Septembers on record as the same weather stations recorded less than one-tenth of an inch of rain.

October saw some improvement, with about 3.5 inches of rainfall, but this was still below average for the month.

National Weather Service Meteorologist Bianca Villanueva said Monday that November continued the trend of dry months with only 0.37 inches of rain recorded at North Texas Regional Airport — Perrin Field. For the first six days of December, Villanueva said the same weather station has recorded. 0.28 inches of rain, more than half the 0.58 inches on average expected for this time of year.

Villanueva said she expects this dry spell to continue for the foreseeable future, with little chance of rain in the extended, 14-day forecast. The greatest chance will come on Thursday, Villanueva said, noting that the chances are still in the single digits.

With the extended dry spell and continued drought conditions, the Texas Weather Connection, a part of the Texas A&M system, said Grayson County ranges from 416 to 568, with an average of 510, on the Keetch-Byram Drought Index. This index measures the combustibility of area plant life based on outside temperature and drought conditions.

The county’s index score would need to be at least 650 before county commissioners typically would consider a burn ban, officials said earlier this week.

Despite the ongoing drought, water levels at Lake Texoma remained high for this time year. As of Wednesday, the pool elevation of the lake stood at 618.78 feet. At this level, all of the lake’s conservation pool was at seasonally-adjust capacity, with 0.57 percent of the flood pool full.