"You know what happened with Memorial Day and Fourth of July weekend: People came together, and the virus took off," Turner said at an Aug. 31 press conference.
The word of caution came with signs of progress for the area, but another 158 cases and eight deaths were also reported. To date, Houston has had 63,834 total cases and 820 deaths.
Turner especially called on Black and Hispanic residents to continue to get tested.
"Please get tested; it is important for you to get tested and know your status," he said.
The city's seven-day positivity rate—the percentage of positive cases out of all tests—is at 7.8%, Turner said.
"It is moving in the right direction," he said. "But as people return to schools and other events, the goal really is to get at 5% ... get below 5% and to stay there."
City officials attributed the drop in positivity to widespread mask-wearing as well as a decline in testing, which was a source of concern for Director of Emergency Medicine David Persse.
"We still need to have folks to go and get tested. ... If people stop going to get tested, we won't be able to calculate a positivity rate, and we won't know what’s going on," he said. "People will get a false sense of confidence."