The number of Americans applying for unemployment benefits dropped by 35,000 last week, but the numbers were skewed by seasonal factors.

The Labor Department says applications fell to a seasonally adjusted 353,000, down from a revised 388,000 the previous week. It was the biggest drop since February 2011.

The four-week average, a less volatile measure, declined 8,750 to 367,250, the lowest since the end of March.

Economists view the recent numbers with skepticism, noting that the government struggles to adjust claims figures to reflect temporary summertime layoffs in the auto industry. Many automakers are foregoing the typical shutdowns because stronger sales have kept plants busier.

When applications are consistently below 375,000, it typically suggests hiring is strong enough to lower the unemployment rate.