How much snow London, Ontario gets, month by month

London's snowfall by month

The normals list snowfall for six months, November to April, and leave May to October blank. Snowfall builds from 19.5 cm in November to a January peak of 52.0 cm, then eases to 26.8 cm in March and 9.6 cm in April.

Where the figures come from

ECCC's 1991 to 2020 Canadian Climate Normals for London combine three stations listed at 278 m: London International Airport, London CS and London A. The snowfall figures come from the London International Airport station, apart from November 2002 to October 2003, when London CS filled in, and they stop in April 2017: 27 years, with one year missing and 92.8% of possible observations. They describe the airport; a storm can leave other parts of the city with more or less.

Snow on the ground

Snow depth, what is lying on the ground, peaks later than snowfall. The normals give an average depth of 9 cm in January and 10 cm in February, against 4 cm in December and March and 1 cm in November. ECCC marks these depths with its code D (at least 15 years of data), from 58.6% of possible observations, so treat them as a rough guide. Snow that lies for weeks also builds up on roofs, and the page on roof snow removal and ice dams explains when that becomes a problem.

Days with enough snow to plow

January averages 3.4 days with at least 5 cm of snowfall, the most of any month, followed by December at 2.8 and February at 2.4. Counting days by depth matters because a seasonal snow contract is built around a trigger depth: the amount of new snow that sends the operator out.

Average days a month with snowfall of at least each depth. Source: ECCC Canadian Climate Normals for London, 1991 to 2020.

Most snowy days are light. January averages 15.2 days with at least 0.2 cm but 3.4 with 5 cm or more, so under a 5 cm trigger most snowy days bring no plow. Ask how walks and steps are handled after a light snowfall, and whether salting is included.

December averages the most days with 10 cm or more, at 1.0. The City works to depths as well: its plows go out on local streets after 10 cm, and its highest-priority roads are salted or sanded when there is less than 5 cm, as the guide to City of London snow rules explains.

The yearly total

London International Airport averaged 194.3 cm of snowfall a year in the 1981 to 2010 normals. The 1991 to 2020 table leaves its yearly cell blank, and adding up the months would not produce an ECCC figure, so the older average is the one to quote.

194.3 cm

Average yearly snowfall at London International Airport, 1981 to 2010 normals.

60.3 days

A year with at least 0.2 cm of snowfall, same station and period.

13.2 days

A year with at least 5 cm of snowfall, same station and period.

Those 13.2 days are a starting point, not a visit count: snow that falls over two days can pass a trigger depth without either day reaching 5 cm, and one long storm can need more than one visit.

Record snowfalls

The largest one-day snowfall in ECCC's long-term record for London, with data from 1940, is 57.0 cm, on a December day in 1977. In the 1991 to 2020 period the largest was 40.0 cm, also in December, in 2006, and the largest November day brought 31.0 cm, in 2008. A day like that leaves several times more snow than a 5 or 10 cm trigger and can take more than one pass to clear.

Recent winters in London

Averages hide big swings. In a December 2025 newsroom post, the City of London said the previous winter, 2024 to 2025, brought "the second-highest accumulation of snow that we've seen in 30 years."

Reporting on a City staff report in August 2025, Global News said the City responded to 121 winter events with 16 full deployments that winter, against 43 winter events and five full deployments in 2023 to 2024. The report said close to 300 cm of snow fell within London and that "consistently cold temperatures prolonged snow cover into April." It does not say where or how the 300 cm was measured, so it cannot be set beside the airport average.

Lake-effect snow and squalls

Lake-effect snow forms when cold air crosses open water that is warmer than the air, picks up moisture and drops it downwind as snow, often in narrow bands called squalls. One area can get heavy snow while another close by gets little.

In November 2023, Global News reported an Environment Canada snow squall watch for London-Middlesex, with ECCC meteorologist Geoff Coulson describing cold air "moving over the relatively warm and open waters of Lake Huron" and "the possibility that some of the snow squall activity could move into the London area." The Weather Network has described London as sitting "in one of the most heavily populated snowbelt corridors in the province's southwest corner."

The City's staff report on 2024 to 2025, as Global News reported it, said "Lake-effect snow created uneven impacts." The normals do not separate lake-effect snow from other snow, so they cannot say how often squalls reach the city.

What the numbers mean for a snow removal season

Four things are worth settling before the first snowfall, on a seasonal contract or a per-visit arrangement:

• Season dates. The normals show snowfall from November to April, and April still averages 9.6 cm, so check that the agreement covers the months you need.
• Trigger depth and visit limits. A lower trigger means more visits, and a winter like 2024 to 2025 can use up a capped number of visits early. Ask what happens once the cap is reached.
• Timing. The City's 2024 to 2027 business plan says a snowfall that ends by late evening leaves City crews time to clear most routes before the school or work day, while early morning snow events are more impactful because crews work through traffic. Ask how an early morning snowfall would be handled at your property.
• The end of the driveway. City plows push snow from the road to the boulevard and fill in driveways, and the City says maintaining property access is the owner's responsibility. After a major snowfall it clears major roads and bus routes before neighbourhood roads and says clearing can take 24 to 48 hours, so the ridge can return after your driveway is done. Ask for it to be included.

The page on seasonal snow removal contracts explains how these terms are written into an agreement. To arrange a season, send a request with your driveway size, the trigger depth you want and the months to cover. Sending a request is free and does not commit anyone to anything.

Questions about London snowfall