Wiarton Willie may not be the best weather prognosticator, but he's getting better, UW students find

Every Feb. 2, people turn to weather prognosticating groundhogs to find out whether there will be six more weeks of winter or an early spring.

In Ontario, most people rely on an albino groundhog named Wiarton Willie. But a new study from the University of Waterloo says Willie, historically, hasn't been great at making predictions.

Fourth year students in the course Ecological Consequences of Climate Change looked at 22 years of predictions by Wiarton Willie to assess his accuracy for Guelph and Waterloo region.

"What we found is that Wiarton Willie, sadly, isn't the greatest at giving us accurate predictions of the start of spring," student Shalini Kathirgamanathan said.

Between 1999 to 2020, Willie was right 32 per cent of the time.

The students looked at his predictions, then collected daily temperature data for March and April of each year, then determined the average spring temperatures and looked at whether temperatures were warmer or cooler than average. Warmer temperatures were connected to an early spring.

But he's getting better

The students also looked at whether Willie's predictive ability improved or not as climate changed. 

An early spring is declared when Willie does not see his shadow.

The students divided the data in half and found in the first 11 years, there was a 27 per cent accuracy in predictions, but since 2010, they found Willie was accurate 36 per cent of the time.

"So, we do see a slight increase," she said. 

Kathirgamanathan said in recent years there have been fewer cold high-pressure systems, which "results in blue skies and us having shadows." 

This trend, combined with warming climates, has been producing earlier springs, she said.

Don't blame the groundhog

South Bruce Peninsula Mayor Janice Jackson said don't blame Willie, though, for inaccurate predictions.

In an interview on CBC Radio's Ontario Morning, Jackson said it may be a problem with the messenger. During a ceremony each year (which this year will be online), Willie tells Jackson whether or not he sees his shadow.

"People always ask if Willie is going to be right or wrong: Willie is right all the time. It's whether or not I understand what he's saying to me — it's me who can get it wrong on occasion," Jackson said.

Start conversations

While Willie's ability to predict an early spring isn't exactly scientific, Kathirgamanathan said it's a fun way to look at how climate change is impacting southern Ontario and start conversations about what the region is experiencing.

"When we talk about glaciers melting … we don't necessarily deal with glaciers. We're in southern Ontario. We don't have a connection with that," she said. "We're not experiencing that change."

But trends in Willie's predictions, like looking at how many outdoor skating days people get to enjoy in southern Ontario, is something where "we can actually see the change."