Home › Cities › Canada › Ontario › St. Catharines
St. Catharines, Ontario climate
Cfa Humid subtropical
St. Catharines has a seasonal cool-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is July with an average daily high near 79°F, while the coldest is January averaging around 22°F at night. Around 27 inches of precipitation falls each year, peaking in June (3.1 inches) and easing off in February (1.4 inches). Winters bring significant snowfall (53 inches of snow per year on average).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation split into rain and snow · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)St. Catharines climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 33 | 34 | 40 | 51 | 62 | 72 | 79 | 78 | 72 | 59 | 48 | 38 |
| Avg temp (°F) | 28 | 28 | 35 | 44 | 55 | 66 | 72 | 72 | 66 | 54 | 43 | 34 |
| Avg low (°F) | 22 | 23 | 29 | 38 | 48 | 59 | 66 | 66 | 59 | 48 | 38 | 29 |
| Precipitation (in) | 1.8 | 1.4 | 1.7 | 2.9 | 2.6 | 3.1 | 2.4 | 2.1 | 2.6 | 2.4 | 2.1 | 1.7 |
| Snowfall (in) | 17.1 | 11.1 | 8.7 | 2.5 | — | — | — | — | — | 0.0 | 2.9 | 10.7 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 33 | 34 | 40 | 51 | 62 | 72 |
| Avg temp (°F) | 28 | 28 | 35 | 44 | 55 | 66 |
| Avg low (°F) | 22 | 23 | 29 | 38 | 48 | 59 |
| Precipitation (in) | 1.8 | 1.4 | 1.7 | 2.9 | 2.6 | 3.1 |
| Snowfall (in) | 17.1 | 11.1 | 8.7 | 2.5 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 79 | 78 | 72 | 59 | 48 | 38 |
| Avg temp (°F) | 72 | 72 | 66 | 54 | 43 | 34 |
| Avg low (°F) | 66 | 66 | 59 | 48 | 38 | 29 |
| Precipitation (in) | 2.4 | 2.1 | 2.6 | 2.4 | 2.1 | 1.7 |
| Snowfall (in) | — | — | — | 0.0 | 2.9 | 10.7 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 78 | 74 | 73 | 73 | 72 | 67 | 63 | 62 | 62 | 72 | 75 | 77 |
| Relative humidity (%) | 86 | 84 | 80 | 78 | 77 | 75 | 73 | 73 | 74 | 78 | 81 | 84 |
| Wind speed (mph) | 12.5 | 11.8 | 10.1 | 8.7 | 6.7 | 6.4 | 6.6 | 6.8 | 8.0 | 9.6 | 10.5 | 11.6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 78 | 74 | 73 | 73 | 72 | 67 |
| Relative humidity (%) | 86 | 84 | 80 | 78 | 77 | 75 |
| Wind speed (mph) | 12.5 | 11.8 | 10.1 | 8.7 | 6.7 | 6.4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 63 | 62 | 62 | 72 | 75 | 77 |
| Relative humidity (%) | 73 | 73 | 74 | 78 | 81 | 84 |
| Wind speed (mph) | 6.6 | 6.8 | 8.0 | 9.6 | 10.5 | 11.6 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 25 years of daily observations at Port Weller (aut), a weather station, about 9 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.