St. Catharines, Ontario Weather by Month and Climate Averages

How much rain does St. Catharines get?

St. Catharines gets 602 mm of precipitation in an average year, spread over about 111 days with measurable rain. That is fewer rainy days than 57% of Canada.

June is the wettest month, with 74 mm. February is the driest, with 32 mm. January has the most rainy days, about 12.

The longest dry spell in the last five years lasted 18 days, to June 7, 2023.

St. Catharines weather by month

St. Catharines weather in January

In January, St. Catharines averages a high of 1°C and a low of -6°C. It gets 40 mm of precipitation over about 12 rainy days. The sun is out about 16% of daylight hours. The January record high is 18°C (2005) and the record low is -22°C (1994).

St. Catharines weather in February

In February, St. Catharines averages a high of 1°C and a low of -5°C. It gets 32 mm of precipitation over about 9 rainy days. The sun is out about 29% of daylight hours. The February record high is 18°C (2018) and the record low is -21°C (2015).

St. Catharines weather in March

In March, St. Catharines averages a high of 4°C and a low of -2°C. It gets 39 mm of precipitation over about 9 rainy days. The sun is out about 34% of daylight hours. The March record high is 21°C (2025) and the record low is -18°C (2003).

St. Catharines weather in April

In April, St. Catharines averages a high of 11°C and a low of 3°C. It gets 69 mm of precipitation over about 11 rainy days. The sun is out about 37% of daylight hours. The April record high is 27°C (2013) and the record low is -5°C (1995).

St. Catharines weather in May

In May, St. Catharines averages a high of 17°C and a low of 8°C. It gets 58 mm of precipitation over about 10 rainy days. The sun is out about 44% of daylight hours. The May record high is 31°C (2012) and the record low is 0°C (2020).

St. Catharines weather in June

In June, St. Catharines averages a high of 23°C and a low of 15°C. It gets 74 mm of precipitation over about 10 rainy days. The sun is out about 49% of daylight hours. The June record high is 33°C (2012) and the record low is 8°C (2003).

St. Catharines weather in July

In July, St. Catharines averages a high of 26°C and a low of 19°C. It gets 55 mm of precipitation over about 8 rainy days. The sun is out about 51% of daylight hours. The July record high is 34°C (2018) and the record low is 12°C (2001). July is one of the most comfortable months to visit.

St. Catharines weather in August

In August, St. Catharines averages a high of 26°C and a low of 19°C. It gets 45 mm of precipitation over about 7 rainy days. The sun is out about 49% of daylight hours. The August record high is 35°C (2001) and the record low is 11°C (2015). August is one of the most comfortable months to visit.

St. Catharines weather in September

In September, St. Catharines averages a high of 22°C and a low of 15°C. It gets 56 mm of precipitation over about 8 rainy days. The sun is out about 49% of daylight hours. The September record high is 33°C (2016) and the record low is 6°C (2000). September is one of the most comfortable months to visit.

St. Catharines weather in October

In October, St. Catharines averages a high of 16°C and a low of 9°C. It gets 47 mm of precipitation over about 9 rainy days. The sun is out about 39% of daylight hours. The October record high is 28°C (2019) and the record low is 0°C (2020).

St. Catharines weather in November

In November, St. Catharines averages a high of 9°C and a low of 3°C. It gets 45 mm of precipitation over about 8 rainy days. The sun is out about 38% of daylight hours. The November record high is 27°C (2022) and the record low is -8°C (2018).

St. Catharines weather in December

In December, St. Catharines averages a high of 3°C and a low of -2°C. It gets 42 mm of precipitation over about 10 rainy days. The sun is out about 20% of daylight hours. The December record high is 19°C (1998) and the record low is -16°C (2004).

Sunshine, humidity and wind in St. Catharines

July is the sunniest month in St. Catharines, with sunshine about 51% of daylight hours. January is the cloudiest, at 16%. Over the year the sun shines about 38% of daylight hours. St. Catharines is sunnier than 65% of Canada.

Humidity peaks in January at 77% and is lowest in March at 70%.

St. Catharines has about 4 days a year above 32°C. St. Catharines is cooler than 53% of Canada.

First and last freeze in St. Catharines

The first fall freeze in St. Catharines typically comes around November 18, and the last spring freeze around April 8. That leaves a frost-free growing season of about 224 days.

St. Catharines weather records

The hottest temperature on record at the St. Catharines station is 35°C, on August 8, 2001. The coldest is -22°C, on January 19, 1994.

The wettest day on record brought 63 mm of rain, on August 31, 2005.

31 all-time records have been set at the station since 1992.

The best time to visit St. Catharines

The most comfortable time to visit is typically July to September, when daytime highs sit near 24°C.

Winter (December–February) is cold, with average highs around 2°C and lows near -4°C.

Spring (March–May) is chilly, with average highs around 10°C and lows near 3°C.

Summer (June–August) is warm, with average highs around 25°C and lows near 17°C. It can feel humid.

Autumn (September–November) is mild, with average highs around 15°C and lows near 9°C.

St. Catharines climate questions

How much rain does St. Catharines get?

St. Catharines gets 602 mm of precipitation in an average year, over about 111 rainy days.

What is the wettest month in St. Catharines?

June is the wettest month in St. Catharines, with 74 mm. February is the driest, with 32 mm.

How many rainy days does St. Catharines have a year?

St. Catharines has about 111 days with measurable rain in an average year. January has the most, about 12.

What is the hottest month in St. Catharines?

July is the warmest month in St. Catharines, with an average high of 26°C.

What is the coldest month in St. Catharines?

January is the coldest month in St. Catharines, with an average low of -6°C.

What is the record high temperature in St. Catharines?

The record high at the St. Catharines station is 35°C, set on August 8, 2001. The record low is -22°C, on January 19, 1994.

What is the sunniest month in St. Catharines?

July is the sunniest month in St. Catharines, with sunshine about 51% of daylight hours. January is the cloudiest.

When is the first frost in St. Catharines?

The first fall freeze in St. Catharines typically comes around November 18. The last spring freeze is around April 8.

What is the best time to visit St. Catharines?

The most comfortable time to visit is typically July to September, when daytime highs sit near 24°C.