The loonie temporarily shot through the 80-cent mark this morning, driven higher by a weaker U.S. dollar and raising questions about how much longer the Canadian currency can continue its sharp “winning streak.”

Having closed yesterday at 79.81 cents U.S., the loonie so far today has been as high as 80.25 cents and as low as 79.76 cents. It was sitting just below the 80-cent level with a few hours still to go before North American markets open.

Canada’s dollar has rallied sharply since hitting a low near 68 cents in January, causing issues for exporters but no doubt raising the spirits of summer vacationers heading into holiday season.

Consider this: A morning cappucino at the Battery Park Ritz-Carlton’s 2West in New York costs a Canadian who converts cash about $10 today. That may be steep for a coffee, but consider that it cost around $11.75 in January.

So where does the loonie go from here?

Kit Juckes, the chief of foreign exchange at Société Générale, believes somewhere around 83.5 cents is reasonable, depending on oil prices and the outlook for the Federal Reserve’s key interest rate.

“That’s a realistic target, after which it gets slower,” Mr. Juckes said.

“But while the Fed’s on hold and oil’s not falling, there’s no great pressure to go back down.”

Jasper Lawler of CMC Markets in London also thinks somewhere above 83 cents is possible, depending on the run-up in oil, whose ups and downs have been moving commodity-based currencies for some time now.

“It’s been quite a winning streak,” he said.

But London Capital Group market analyst Ipek Ozkardeskaya isn’t so sure, citing questions about whether the oil market “may have gone well beyond itself.

A drop in oil prices, she added, could “compromise the loonie’s strength above the 80-cents mark.”