A KEY BAROMETER of the state’s fight against COVID-19 rose sharply on Sunday.

The positive test rate (positive tests as a percentage of total tests) jumped to 2.65 percent, its highest level since June 14.

The seven-day average of the positive test rate, which smooths out temporary ups and downs, remained at 2.2 percent, the level it reached on Saturday. Still, the positive test rate has been on a steady upward climb, rising from 1.8 percent on July 27 to 2.65 percent Sunday.

The seven-day rate might even be higher but for an unusually high number of tests conducted late last week. On Friday, for example, the state conducted 19,151 tests, the highest level in two months. That higher level of testing increases the denominator of the positive test rate calculation and helps drive down the positive test rate; in July, the average number of daily tests was 10,891.

Gov. Charlie Baker has been following the situation closely, suggesting last week that tougher measures may be necessary if the numbers keep going up.  He blamed most of the increase on “lapses of judgment” by people at parties and larger gatherings.

“The situations that I just recapped are a recipe for disaster and have to stop if we want to continue to reopen and get back to a new normal,” Baker said on Friday.

“It’s a slow creep and what we’re saying is we want the slow creep to stop and go back down,” said Marylou Sudders, the governor’s secretary of health and human services.