Ottawa Snowfall Totals & Accumulation Averages

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This page pulls together information on when, how much and how often Ottawa, Ontario has snow.

There are data and descriptions here of how many days it snows and the total amount of snowfall that Ottawa usually gets. There are also monthly and yearly counts of the days that Ottawa normally has heavy snowstorms and deep snow accumulated on the ground. Plus there's information on when the city can expect its first and last snowfalls of the season.

All the numbers are long-term historical averages based on weather data gathered from 1981 to 2010 near downtown Ottawa.

How Often it Snows in Ottawa

This first table lists monthly and yearly totals for amount of snow and how many days it snows at least 0.2 centimetres (0.08 inches).

Average total snowfall and days with fresh snow in Ottawa
Days   Inches Centimetres
14.1 January 17.4   44
  9.7 February 13.7   35
  7.4 March 11.4   29
  2.7 April   2.8     7
  0.1 May   0.0     0
  0.8 October   1.1     3
  5.1 November   6.3   16
12.2 December 16.3   41
52.0 Year 69.1 175

When Ottawa Has Its First & Last Snowfalls

The first snowfall of winter for Ottawa usually arrives in November, but can show up as early as October. A freak snow flurry in September has appeared, but the snow quickly melted.

The season's last snowfall typically happens in April although in some years a late skiff or even a dump of snow lands in May.

Ottawa is normally free of snow every year from June to August.

How Many Snowstorms Ottawa Gets

Most days of snowfall in Ottawa leave less than five centimetres (2 inches), of fresh snow on the ground. For 12 days a year on average, the amount of new snow totals at least five cm.

Big snowstorms of over ten cm a day normally occur about three or four times a year. But major blizzards that dump 25 cm or more in one day are rare events that happen once a decade.

Number of days per month and year on average in Ottawa with a total snowfall of at least 5, 10 or 20 centimetres
  5 cm
2.0 inches
10 cm
3.9 inches
25 cm
9.8 inches
January   2.8 0.7 0.0
February   2.2 0.8 0.0
March   2.4 0.7 0.0
April   0.4 0.2 0.0
October   0.1 0.1 0.0
November   0.9 0.4 0.0
December   3.0 0.9 0.0
Year 11.7 3.7 0.1

How Much Snow Normally Accumulates in Ottawa

For about 115 days a year, Ottawa has at least a centimetre of snow on the ground. In mid-winter the snowpack averages from 21 cm deep.

Generally the snow cover begins to build in December and remains deep throughout most of January and February.

Average total days per month and year in Ottawa with snow depth of at least 1, 5, 10 or 20 cm on the ground
1 cm
0.4 inches
5 cm
2.0 inches
  10 cm
3.9 inches
20 cm
7.9 inches
  30.6   28.5 January 23.8 10.8
  27.9   27.5 February 24.6 14.2
  24.6   22.3 March 18.8 11.1
    3.8     1.9 April   1.0   0.3
    0.4     0.2 October   0.0   0.0
    4.9     2.8 November   1.4   0.2
  22.8   18.4 December 11.2   3.1
114.9 101.6 Year 80.8 39.8
Reference

Environment Canada. Meteorological Service of Canada. Canadian Climate Normals. 1981-2010 Climate Normals & Averages.

Environment Canada. National Climate Data and Information Archive. Canadian Climate Normals or Averages 1971-2000.

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