The loonie slipped 0.16 of a cent to 90.2 cents US.
U.S. home prices fell for the second straight month in December as severe winter weather, tight supply and higher costs combined to slow sales.
The Standard & Poor’s/Case-Shiller 20-city home price index declined 0.1 per cent from November to December.
Other data showed a dip in American consumer confidence. The Conference Board's index showed the index declined to 78.1 in February from 79.4 in January because of adverse weather.
Commodity prices declined with markets rattled by a deceleration in the rise of Chinese housing prices in January and weakness in China’s currency, which has long been a one-way bet on slow, steady appreciation.
Last week’s decline in the tightly controlled yuan prompted suggestions Beijing might be trying to support exporters and help offset weakening domestic demand. That came after an HSBC survey showed Chinese manufacturing activity in February tumbled to a seven-month low.
The April crude contract on the New York Mercantile Exchange fell $1.25 to US$101.57 a barrel.
March copper fell for a second day, down one cent to US$3.26 a pound while April gold advanced $4 to US$1,342 an ounce.
Traders also awaited key trade and growth data later in the week.
Statistics Canada releases growth data for December and the fourth quarter on Friday. Economists looked for the economy to contract by 0.3 per cent in December, largely because of crippling ice storms in Ontario and Quebec.
On Thursday, the agency reports the latest data on the country’s major trade indicator. CIBC World Markets believes the current account deficit is expected to grow by $2 billion to $17.5 billion.
Friday will also see the release of the first revision to U.S. fourth-quarter gross domestic product growth. The initial reading came in at 3.2 per cent but worsening weather in December likely pushed growth down to around 2.7 per cent.