Figures released by Thinkbox, which promotes advertising on television, showed that the total number of commercial impacts, or ads seen, rose by 6% compared with the same period last year.
The figures are based on research by BARB and only include domestic broadcast television, which means that the time spent by people watching television online isn't "stealing" hours from traditional broadcast.
The figures also show that the ABC1 audiences loved by advertisers are watching 9% more television than last year, and that 16- to 34-year-olds are watching 3% more.
Thinkbox has attributed the increase in television viewing to increased digital television penetration, what it called a 'creative renaissance' in UK advertising and the British climate, which keeps many people indoors.
New technologies are also boosting television hours and commercial impacts, with research from Sky's Skyview panel showing that households watch 5% more ads on television when they get the Sky+ service.
Tess Alps, Thinkbox's chief executive, said: "This is a shaft of very bright light that cuts through any economic gloom. Broadcast TV revenues held firm in the first half of 2008, and, whatever the economic climate holds for the advertising market, I hope these figures will underline the great strength and resilience of commercial TV."
Her comments make a stark contrast to the reaction to ITV's results, when the broadcaster revealed that profits were down by 28% for the first half of the year.
The research does not currently include television watched on catch-up services such as Channel 4's 4OD and ITV.com, but Thinkbox last week said it had commissioned further research to examine how and why people use online TV, its relationship to broadcast TV and the advertising opportunities it affords, with preliminary results expected before the end of the year.