Saint Catharines (ON) Temperature by Month

Saint Catharines in Ontario, Canada sees significant seasonal temperature differences, with daytime highs between 1°C (34°F) in January and 26°C (79°F) in July, averaging 13°C (55°F) annually. Explore the full monthly breakdown below.

Depending on the time of the year, temperatures range from warm to very cold in Saint Catharines. Nighttime lows follow the same pattern, ranging from 20°C (68°F) to -6°C (21°F).

The chart below illustrates the average maximum day and minimum night temperatures in Saint Catharines by month:

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. July, the warmest month of the year, receives 307 hours of sunshine.

The chart below shows the average temperature throughout the year:

Saint Catharines's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters, and seasons reversed compared to Europe.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Saint Catharines, January is the coolest month, with average highs of 1°C (34°F) and humidity around 76%, considered high. In July, the warmest month, temperatures average 26°C (79°F) with 68% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Saint Catharines this rarely lasts long on the ground.

For more on Saint Catharines's weather, including monthly rainfall, sunshine hours, and humidity, visit our Saint Catharines climate page.