A new Harris Poll finds that adult Internet users are now spending an average of 13 hours a week online. Of course, people’s usage varies greatly; one in five  of adult Internet users are online for only two hours or less a week while one in seven are spending 24 or more hours a week online. While this usage shows a steady increase in hours online since the seven-hour average of 1999, it’s still slightly below th 14-hour average in October 2008, as Internet users flocked to the Web to hear about the economic downturn and watch U.S. election coverage.

Additonal Harris Poll findings: 

* 30-39 year olds average 18 hours online, and two age groups – 25-29 and 40-49 - each averaged 17 hours. The 184 million total adults online has held steady since 2007, and represents 80 percent of all adults. What’s important, however, is that this figure includes those at home, at work, at school, and at any other location. What has increased steadily, however, are the number of adults who are online at home. That figure is now 76 percent; the 2005 figure was 66 percent, 2006 70 percent, and 2008 75 percent.

Harris conjectures that the increase is probably due to a growing ability to use the Internet, an increase in sites and applications, an increase in watching TV online and more online purchases. They also suggest that the U.S. recession may have something to do with consumer’s interest in free entertainment. We suggest it may as well be demonstrative of the growth of telecommuting, and people creating work-at-home companies of their own.

Here’s the announcement, with tables that break out the numbers.