At 9.61 kronor to the dollar, the krona has fallen 4.15 percent so far this year, according to Bloomberg News' weekly dollar index.
It is the weakest of the so-called G10 currencies - the world's most traded and liquid currencies.
Other G10 currencies that have lost ground against the US dollar are the Japanese yen, down 2.11 percent, and the Swiss franc, down 2.04 percent.
The Norwegian krone has been the strongest performer, up 7.61 percent against the dollar. The Australian and New Zealand dollars have risen 7.36 and 2.73 percent, respectively.
Last year, it was instead the Swedish krona that strengthened against the US dollar week after week.
