For the past four years, Tim Armstrong has been marking the progress of receding ice on his blog "Lake of the Woods Ice Patrol."

Armstrong, who is a pilot, gets regular birds eye views of the sprawling northwestern Ontario lake, and many of the smaller inland lakes close by.

What he has been seeing, and documenting, has left him "dismayed" that a later than normal ice out is likely.

"We are running late," says Armstrong. "And (my) aerial photography backs that up. We are looking comparable to 2014. Which was a late spring. But what has me more worried is the reports I'm getting on the thickness of the ice. And the strength of the ice. Combined with the forecast for the rest of April, which is for things to stay cold."

Armstrong said his aerial photos show there's been no ice melting progress now for about three weeks. In fact, he notes April has been so cold that parts of the lake that had open water in March, have refrozen.

Armstrong said the fact the forecast for the rest of April is for below-normal temperatures is not helping the situation. He said the presence of thick, hard ice and a layer of snow complicates things further.

"We've still got snow cover on Lake of the Woods, " he said. "So the sun is shining well...but it's not really penetrating to the ice to create that slush, and the darkening of the surface that starts to turn the corner.

Armstrong said at present the lake is about 99% ice covered. Only areas of high current, such as Keewatin Channel, have visible open water.

He said as a comparison,it was a lot different on the lake a year ago.

"Last year at this time the ice was dark, it was clearly deteriorating, open water was expanding rapidly...to the point that people were putting boats in the water for limited use," he said.

Tim Armstrong is the man behind the blog "Lake of the Woods Ice Patrol." He says this April and it's unseasonable cold has not been conducive to melting ice.  (photo: Tim Armstrong )

Armstrong said his photographic records go back to 2003, and 2014 was the worst year in his archives. He said that year, the last ice on Lake of the Woods didn't go until May 21. One of his blog sight visitors noted that during the cold spring of 1996, the ice didn't leave LOTW until May 25.

Armstrong said his web sight gets very busy during late springs as cottagers get antsy and want ice cover information.

"Bad years generate intense interest," he said. "Because if the ice goes out early everybody sticks to their normal plan and come to Kenora from wherever...and they can do what they always do. A lot of people like to make an early trip out in April if they can..."

Although Armstrong does not like to forecast when the ice will depart Lake of the Woods this year, his rough estimate is some time between May 11 and May 15. But he notes there are many things that create good ice melting conditions, and not many are in play yet this April.

"It's all gonna depend on how soon we can get the right weather. We need warm air,we could use rain to eliminate ice cover," he said. "And I still don't know how to reckon with the unusual thickness of the ice quality that's here. There are too many factors to make a clear guess."