WASHINGTON — Unemployment rates fell in 43 U.S. states in January as more Americans began looking for work and most quickly found jobs.

The Labor Department said Monday that the unemployment rate rose in just one state — Iowa — where the rate increased to 4.3 percent from 4.2 percent. Still, that’s far below the national rate of 6.6 percent that month. Rates were unchanged in six states.

The data demonstrates that the steady decline in the unemployment rate nationwide has been broad-based, occurring throughout much of the country. The overall U.S. unemployment rate has fallen 1 percentage point in the past 12 months.

Twenty-three states reported more hiring in January, while 27 said that the number of jobs fell. Harsh winter weather weighed on hiring nationwide, with employers adding just 129,000 jobs in January. That’s below the average monthly gain of about 180,000 in the previous two years.

The job gains are calculated from a survey of employers, while the unemployment rate stems from a separate survey of households. The two surveys sometimes produce disparate results. In January, the household survey painted a more positive view of the nation’s job market than the employer survey did.

Rhode Island had the highest unemployment rate, at 9.2 percent. The state’s economy has suffered from a housing bust and manufacturing slump. Illinois and Nevada had the next highest rates, both at 8.7 percent, followed by California, with 8.1 percent.

North Dakota had the lowest rate, at 2.6 percent. It has benefited from an oil and gas drilling boom. Nebraska had the next-lowest rate, at 3.5 percent, followed by South Dakota at 3.6 percent.

Nationwide, hiring improved in February, as employers added 175,000 jobs. The unemployment rate rose to 6.7 percent, but partly for an encouraging reason: more Americans started searching for jobs, though most didn’t find one right away. Still, the fact that they began job hunting suggests they were more encouraged about their prospects.

The states with the biggest job gains in January were Texas, which added 33,900 positions, mostly in construction, education and health, and restaurants and hotels. Ohio had the next-largest gain, with 16,700, followed by Arizona, with 8,900. Vermont, Rhode Island and Nevada also reported healthy increases.

California posted the largest decline, losing 31,500 positions, mostly in construction, government and in a category that includes retail, transportation and utilities. It was followed by Illinois, which lost 27,600, and Kentucky, with a drop of 18,500.