2012 was the second-wettest year in Dorset since records began in 1910.
Statistics from the Met Office show 1262.4mm of rain fell in Dorset last year - 133 per cent above average.
The only year more rain fell in Dorset was in 1960, when 1357.1mm was recorded.
The data suggests that Dorset and the UK is becoming wetter. Nationally, 2012 was also the second wettest year - only beaten by 1337.3 mm falling in 2000.
Professor Julia Slingo, Chief Scientist at the Met Office said: "The trend towards more extreme rainfall events is one we are seeing around the world, in countries such as India and China, and now potentially here in the UK.
"Much more research is needed to understand more about the causes and potential implications.
"It's essential we look at how this may impact our rainfall patterns going forward over the next decade and beyond, so we can advise on the frequency of extreme weather in the future and the potential for more surface and river flooding."
Flooding has brought chaos to Dorset this year, and it is thought that extreme rain may occur more regularly in the future.
A Met Office spokesperson added: "We have always seen a great deal of variability in UK rainfall because our weather patterns are constantly changing.
"However, preliminary evidence suggests we are getting slightly more rain in total and it may be falling in more intense bursts."
Have a look at the latest weather report for Dorset