Climate and weather averages
What Ottawa's weather is normally like, month by month, from the official Environment Canada climate normals.
A climate normal is a thirty-year average, not a forecast and not last year. Comparing a normal against today’s weather is how you tell whether a day is unusual for the time of year. This page uses the 1981-2010 normals for OTTAWA CDA (Ottawa CDA (Central Experimental Farm)).
The year at a glance
Month by month
| Month | Mean °C | Daily high °C | Daily low °C | Rain mm | Snow cm | Precip mm |
|---|---|---|---|---|---|---|
| January | -10.2 | -5.8 | -14.4 | 23 | 44 | 63 |
| February | -7.8 | -3.1 | -12.5 | 18 | 35 | 50 |
| March | -2.2 | 2.4 | -6.8 | 29 | 29 | 57 |
| April | 6.5 | 11.4 | 1.5 | 63 | 7 | 71 |
| May | 13.5 | 18.9 | 8.0 | 87 | 0 | 87 |
| June | 18.7 | 24.1 | 13.3 | 93 | 0 | 93 |
| July | 21.2 | 26.6 | 15.7 | 84 | 0 | 84 |
| August | 19.9 | 25.4 | 14.5 | 84 | 0 | 84 |
| September | 15.3 | 20.4 | 10.1 | 93 | 0 | 93 |
| October | 8.4 | 12.8 | 4.0 | 83 | 3 | 86 |
| November | 2.0 | 5.5 | -1.5 | 67 | 16 | 83 |
| December | -5.6 | -2.0 | -9.2 | 32 | 41 | 70 |
The same station records an average of 2,084 hours of bright sunshine a year, and 161 days a year with measurable precipitation. Sunshine is measured with a recorder rather than estimated from cloud cover, which is why some stations — Halifax among them — do not publish it.
Frost and the growing season
The frost-free period averages 158 days a year at this station. The last frost of spring falls around day 120 of the year and the first frost of autumn around day 279. Days are counted from 1 January.
Official sources
Details such as fares, fees, hours and program rules change. Always confirm against the official source before acting on anything time-sensitive.