(Adds dealer quotes and details throughout; updates prices) * Canadian dollar weakens 0.1% against the greenback * Touches its weakest level since last December at 1.2948 * Price of U.S. oil settles 2.2% lower * Canadian retail sales rise 4.2% in June from May By Fergal Smith TORONTO, Aug 20 (Reuters) - The Canadian dollar on Friday rebounded from an earlier 8-month low against the greenback, helped by strong domestic data and a stock market rally, but the currency was still lower for a fifth day and posted its biggest weekly decline since March last year. The Canadian dollar was trading 0.1% lower at 1.2845 to the greenback, or 77.85 U.S. cents, after touching its weakest intraday level since last December at 1.2948. For the week, it was down 2.6%. "The CAD was able to claw back most of those overnight losses with the firm reading in the Canadian retail sales report and comments by Fed"s Kaplan which helped to shift the negative sentiment in equity markets," said Tony Valente, a senior FX dealer at AscendantFX. It "kind of feels like a blow off top (in USD-CAD), a move that got too far ahead of itself," Valente added. Canadian retail sales surged 4.2% in June from May, led by a strong rebound in demand for clothing and accessories, while July retail sales likely fell 1.7%, data showed. Wall Street capped a tumultuous week with a broad-based rally, while Dallas Federal Reserve President Robert Kaplan, among the central bank"s most forceful supporters for starting to reduce support for the economy, said he may need to adjust that view if the Delta variant of the coronavirus slows economic growth materially. Surging Delta variant cases continued to weigh on oil, with investors less bullish about fuel demand. U.S. crude oil futures settled 2.2% lower at $62.32 a barrel, trading at three-month lows. Meanwhile, the United States extended the closure of its land borders with Canada and Mexico to non-essential travel such as tourism through Sept. 21. The Canadian 10-year yield rose 1.8 basis points to 1.146%, tracking the move in U.S. Treasuries. (Reporting by Fergal Smith; Editing by Anil D"Silva and Franklin Paul) Our Standards: The Thomson Reuters Trust Principles.