The Canadian dollar was trading lower Tuesday as weak economic data from China, weak oil prices and general U.S. dollar strength combined to push the loonie to a three-month low against the U.S. dollar.

The Canadian dollar closed down more than a quarter of a cent at 91.24 cents US. In earlier trading, it went as low as 91.10 cents. That was the lowest it's traded at since May 2. 

"Since its July 3rd high, [the Canadian dollar] has lost three per cent, highlighting the vulnerability around the currency," said Scotiabank’s chief foreign exchange strategist Camilla Sutton in a morning commentary.

"The core risk for [the Canadian dollar] this week is Friday’s employment release," she said.

Analysts expect job gains of 25,000 in the month of June, with the unemployment rate ticking down to 7.0 per cent.

But job growth failed to match expectations in the previous month, leading to uncertainty.

West Texas Intermediate Oil, which was selling for $105 US a barrel as recently as June, is now hovering around the $98 mark.

HSBC's index of China's service industries activity fell to 50.0 in July from 53.1 in the previous month. The weak figure shows the impact of a slowdown in China's property market, said HSBC chief China economist Qu Hongbin.

Long-term forecasts generally see the loonie dropping further into the 85- to 88-cent range by next year.

With files from the Canadian Press