In European trade on Wednesday (Oct 26), / was temporarily trading at 0.9859, down 0.17%.
Another rate rise, probably by 75 basis points, is expected on Thursday.
They have raised borrowing costs by 125 basis points since July.
The euro zone rose 9.9 percent in September from a year earlier, the highest on record and the fifth month in a row that it has beaten expectations, Eurostat data showed.
With a recession likely already under way, the European Central Bank could face a similar situation this week as it did in 2008, when policy makers also raised interest rates amid an economic downturn, only to quickly turn them into cuts as the global financial crisis deepened.
The euro/dollar climbed above the 0.99 mark again on Tuesday.
For economists at Commerzbank, there are still plenty of uncertainties that could soon sour euro sentiment.
