Ontario winters are more than a nuisance—they are a legal flashpoint. Each year, slip-and-fall claims on icy sidewalks, parking lots, and trails trigger disputes over whether responsibility lies with municipalities or with private contractors hired to clear snow and ice. Courts are asked to draw difficult lines between policy decisions, operational mistakes, and contractual obligations. Understanding where liability falls is critical for plaintiffs, defendants, and the mediators who help resolve these cases.

The Municipal Standard of Gross Negligence

Municipal liability for icy sidewalks is governed by section 44(9) of the Municipal Act, 2001, which requires proof of gross negligence. This is a higher standard than ordinary negligence and demands clear evidence of serious shortcomings in winter maintenance.

In Cerilli v. Ottawa (City) 2008 ONCA 28^[1], the Ontario Court of Appeal confirmed that prolonged inaction in the face of obvious icy hazards can meet this threshold. In that case, the City was aware of freeze–thaw conditions and yet failed to respond in time. The court found that the failure to address the risk adequately amounted to gross negligence.

Policy Immunity and Its Limits

Municipalities often argue that snow-clearing decisions are policy choices and therefore immune from liability. While high-level allocation of resources may indeed be immune, the Supreme Court of Canada has drawn a sharp boundary between policy and operations.

In Nelson (City) v. Marchi, 2021 SCC 41, [2021] 3 S.C.R. 55^[2], the Court held that piling snow in a way that blocked access to sidewalks was an operational act, not a policy decision. The City was therefore exposed to liability despite arguing that snow removal strategies were immune. The ruling makes it clear that municipalities cannot hide behind broad policies when the day-to-day execution of those policies creates unsafe condition

The Role of Contractors and Occupiers

Many municipalities and commercial property owners contract out their winter maintenance. But contracting out does not mean contracting away responsibility. Under Ontario’s Occupiers’ Liability Act^[3], occupiers must still ensure that premises are reasonably safe, regardless of whether a “competent contractor” has been hired. I wrote a recent blog on the topic “Hiring a Competent Contractor: Shield or Mirage”^[14].

The courts have consistently reinforced this principle. In Wilson v. 356119 Ontario Ltd. et al., 2023 ONSC 600^[5], involving a Brockville mall parking lot, the contractor had failed to salt adequately, and inspections were lacking. The occupier and the contractor were both found liable, with contributory negligence apportioned to the plaintiff.

Similarly, in Sprowl v. First Capital, 2025 ONSC 3628^[6], the property owner and its contractor were found fully responsible for inadequate plowing, salting, and inspection. The court held that both had breached their statutory duty under section 3(1) of the Occupiers’ Liability Act by failing to keep the premises reasonably safe.

These decisions illustrate that occupiers cannot simply rely on the existence of a contract—they must ensure the work is carried out effectively. Contractors, meanwhile, remain directly liable for their own negligent performance.

The Procedural Trap of Notice Requirements

Even where liability appears strong, plaintiffs face another obstacle: the Municipal Act, 2001<^[7] requires that written notice of a claim be served on a municipality within ten days of the incident. Courts will excuse non-compliance only if the plaintiff provides a reasonable explanation and if the municipality is not prejudiced by the delay.

This notice requirement has tripped up many otherwise valid claims, and it remains a critical procedural step in any slip-and-fall case against a municipality.

Context Matters: Public Parks and Trails

Not all properties are treated equally under winter maintenance law. Courts consider the context of the property’s use when assessing what is “reasonable.”

In Franklin et. al. v The City of Greater Sudbury, 2016 ONSC 4739^[8], a case involving Delki Dozzi Park, the court held that reduced winter maintenance may be acceptable in low-traffic recreational areas. The expectation for municipal vigilance is different in a park than on a busy city sidewalk, where heavier pedestrian use demands greater care.

The Puzzle Pieces

In winter maintenance litigation, success for plaintiffs almost always turns on the quality of the evidence. Courts demand more than mere proof of a fall on ice. They look for a clear record showing that a municipality or its contractors failed to act reasonably in the face of known or foreseeable hazards. Over time, case law has developed a consistent picture of the types of evidence that carry weight.

Weather records are often the first puzzle piece. Historical Environment Canada data, together with expert meteorological analysis, is frequently used to show freeze–thaw cycles or rainfall that would have alerted a reasonable municipality to dangerous conditions. In Cerilli, the Ontario Court of Appeal emphasized that the City had ample notice of the weather patterns that created the icy hazard, yet failed to respond adequately, a failure the court deemed gross negligence.

Maintenance logs and inspection records form another critical category of evidence. Courts examine whether there were documented patrols, salting, or sanding in the hours before the accident. In Wilson, Justice Doyle noted that the winter maintenance contractor’s failure to apply salt early enough, despite a known risk of ice, was a key factor in the finding of liability. The inspection system had broken down on the very day it was most needed.

Eyewitness testimony and photographic or video evidence also play a decisive role. In Sprowl, the court was persuaded not only by expert analysis but also by evidence showing the lot was inadequately treated at the time of the fall. Justice Smith relied on witness descriptions of the ice, alongside the absence of adequate inspection or salting, to hold both the occupier and its contractor 100% liable.

Finally, municipal policy documents and testimony from staff can tip the scales. Courts are prepared to accept that municipalities cannot prevent every slip, but they expect to see functioning systems that are properly resourced and diligently carried out. The Supreme Court’s decision in Nelson illustrates this balance. There, the City argued that its snow-clearing plan was a matter of high-level policy, but the Court found that the operational decision to leave snowbanks blocking sidewalks, without ensuring safe pedestrian access, was unreasonable and actionable.

Together, these pieces—weather records, maintenance logs, witness evidence, and operational documents—form the evidentiary foundation that plaintiffs’ counsel must assemble. Without them, claims risk dismissal. With them, courts have consistently found municipalities and their contractors liable for gross negligence in the face of winter’s hazards.

Conclusion

The “Winter Maintenance Puzzle” is about more than ice and snow. It is about how municipalities and contractors balance planning with execution. Municipalities cannot rely on abstract policy to shield themselves from liability when operational failures cause harm. Contractors cannot cut corners without facing direct exposure. Occupiers cannot discharge their duty simply by outsourcing their responsibilities. And plaintiffs cannot forget the procedural traps that may bar their claims before they are even heard.

Ultimately, the courts demand not perfection but reasonableness. Yet when maintenance systems exist only on paper and hazards remain untreated on the ground, both municipalities and contractors are likely to find themselves liable. The lesson is clear. In winter maintenance, the law rewards diligence and punishes delay.