At a rate of 9.76 kronor to the dollar, the Swedish krona has fallen 5.40 percent so far this year, according to Bloomberg News's weekly dollar index.
It is the worst-performing of all the so-called G10 currencies - the most traded and liquid currencies in the world.
Other G10 currencies that have lost ground against the US dollar are the Canadian dollar, down 3.32 percent, and the Danish krone, down 3.14 percent.
At the other end of the scale are the Australian and New Zealand dollars, up 3.34 and 2.03 percent respectively, and the Norwegian krone, which has risen 1.56 percent.
Last year, it was instead the Swedish krona that strengthened against the US dollar week after week.
