The Australian dollar is three quarters of a US cent higher, helped by a US Federal Reserve in no hurry to hike its interest rate and some positive local economic data.

At 1200 AEDT on Wednesday, the local unit was trading at 78.56 US cents, up from 77.70 cents on Tuesday.

US Federal Reserve chair Janet Yellen told a Congressional committee that the US labour market still showed some weakness and inflation continued to fall, making any interest rate hike unlikely before June.

Easy Forex currency dealer Liam Moon said Dr Yellen’s testimony was the main reason for the Aussie dollar’s surge.

“Janet Yellen’s speech was very timid,” he said.

“The Chinese market came back from the Chinese New Year holidays, and that’s probably why you saw a spike in the Aussie as well.”

Official local data out on Wednesday showed that total hourly rates of pay, excluding bonuses, rose by 0.6 per cent in the December quarter for the second quarter in a row, which matched market expectations.

“The wage price index was quite positive and is important because the quarter Wage Price Index gives us a bit of insight into the labour market and where employment is going,” Mr Moon said.

Financial markets will be waiting for Dr Yellen’s second day of testimony to Congress, as well as local business investment data for the December quarter, due out on Thursday.

Meanwhile, the bond market was firmer at noon.

The March 2015 10-year bond futures contract was trading at 97.525 (implying a yield of 2.475 per cent), up from 97.495 (2.505 per cent) on Tuesday.

The March 2015 three-year bond futures contract was at 98.150 (1.850 per cent), up from 98.140 (1.860 per cent).