The euro was down at almost $1.4, off more than 8 percent from its all time peak set in mid-July and on pace for its worst monthly loss since its launch in 1999.
Friday's reports follow data earlier in the week showing greater-than-expected U.S. economic growth in the second quarter and strong durable goods orders for July.
The dollar was down against the yen at around 108 yen, but was up nearly 1 percent this month.
The U.S. dollar rose 1.2 percent versus the Canadian dollar to C$1.0631, its biggest one-day gain in three weeks, after data showed the Canadian economy narrowly skirted a recession in the second quarter, growing 0.3 percent. Economists were expecting a 0.7 percent expansion.
Weak Canadian Dollar, Sterling
Still, some analysts say a weak gross domestic product number is not sufficient to warrant an interest rate cut from the Bank of Canada.
"Though Canadian growth may prove slightly weaker than expected in H1 2008, the accumulated impact of rate cuts to date should help cushion any downside risks,'' said analysts at Morgan Stanley in a research note.
"On the other hand, inflation remains elevated, even if the recent decline in commodity prices suggests scope for softening price pressures.''
Sterling was also one of the major casualties in the currency market this month, down 8.1 percent versus the dollar, its biggest drop since it crashed out of the Exchange Rate Mechanism in 1992.
The pound last traded down 0.4 percent at $1.8207 on the day.
The Australian dollar fell nearly 9 percent in August, its worst month since February 1989, according to Reuters data, on expectations of narrowing interest rate differentials between
the United States and Australia. It last traded at US$0.8579 , down 0.6 percent.
Investors expect sentiment on the U.S. dollar to remain bullish in the coming week. But some market participants could to try to square positions by selling into any dollar strength ahead of next Friday's August U.S. employment report and central bank policy decisions in the euro zone and the UK.
Analysts expect next week's U.S. non-farm payrolls report to show a 73,000 contraction, according to a Reuters poll.
"U.S. payrolls will likely show a decline, but markets will only be moved if losses exceed 100,000, having gotten used to the slow drip of job shedding this year,'' said Avery Shenfeld, a senior economist at CIBC World Markets in Toronto.