Maine’s unemployment rate rose slightly from July to August, still below the 4 percent mark of one year ago.

The seasonally adjusted rate of 3.8 percent in August is a preliminary number, and slightly higher than July’s 3.7 percent rate, according to the Maine Department of Labor. In August of 2016, the rate was 4.0 percent.

The rate has remained at or below 4 percent for the past 23 months, extending the second-longest period in more than 40 years that the unemployment rate has held at that level.

The U.S. unemployment rate also increased one-tenth of 1 percent from July to August, rising from 4.3 percent to 4.4 percent, and is down from the 4.9 percent of August a year ago.

The New England unemployment rate averaged 4.0 percent. Individual states’ rates were 2.7 percent in New Hampshire, 3.0 percent in Vermont, 4.2 percent in Massachusetts, 4.3 percent in Rhode Island, and 4.8 percent in Connecticut.