Balmy March temperatures have had some Minnesotans running to the nearest golf course or ice cream shop.

But something that doesn't run so well in the unseasonable warmth is sap.

Maple trees, experts say, get their sweet juices flowing best when days are warm but nights are frosty. And you may have noticed that frost has been pretty scarce across Minnesota lately.

St. John's University biologist Steve Saupe tells the St. Cloud Times it's still early enough that a temperature drop could save the season.

But while he's not worried, Saupe, who has studied local syrup production over the years, admits to being "a little concerned" that weather patterns are not showing the type of cold that makes for a vigorous sap run.

A naturalist in the Minneopa area has a similar take on this year's syrup production.

Scott Kudelka tells MPR News that while there's not as much sap running as he might expect, "It's still clear — it hasn't turned milky on us, which is what you're afraid of as warmer temperatures go along."

Ideal conditions for sap – the sweet spot, you might call it – occur when highs reach 50 and night-time lows are in the 20s, Saupe tells the Times.

The Minnesota Maple Syrup Producers Association says there are only 17 states where pure maple syrup is produced and it only happens during this time of year.

The Department of Natural Resources produced a 2013 video (there was snow that year) showing how sap is collected and boiled into syrup.

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The DNR is hosting a series of syruping events at state parks. Find the schedule here.