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Monthly climate in St. Catharines, Ontario, Canada

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification St. Catharines features a humid continental climate (Dfb).Temperatures typically range between -2 °C (29 °F) and 23 °C (73 °F) through the year, but rarely can drop to -19 °C (-2 °F) or can rise to as high as 30 °C (87 °F).The average annual precipitation amounts to about 1088 mm (42.9 inches) and receives 141 rainy days on the 1 mm (0.04 inches) threshold annually.St. Catharines enjoys an average of 2838 hours of sunshine throughout the year, and daylight varies from 9 hours 1 minutes to 15 hours 18 minutes per day.

Monthly average temperatures in St. Catharines, Ontario, Canada §

The warmest months in St. Catharines are July, August and September, with daily mean temperatures ranging from 19 to 23 °C (66 - 73 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -2 to 1 °C (29 - 35 °F) throughout the day. On average each year, St. Catharines experiences 33 days above 25 °C (77.0 °F) and 82 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in St. Catharines, Ontario, Canada.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to June 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum 12°C
(54°F)		 14°C
(57°F)		 15°C
(60°F)		 18°C
(65°F)		 24°C
(75°F)		 27°C
(81°F)		 30°C
(87°F)		 29°C
(84°F)		 29°C
(85°F)		 26°C
(78°F)		 19°C
(66°F)		 15°C
(60°F)
Mean maximum 9°C
(49°F)		 10°C
(50°F)		 13°C
(55°F)		 16°C
(61°F)		 23°C
(73°F)		 26°C
(79°F)		 28°C
(83°F)		 28°C
(82°F)		 27°C
(80°F)		 23°C
(74°F)		 16°C
(60°F)		 11°C
(52°F)
Average high 0°C
(33°F)		 1°C
(34°F)		 4°C
(40°F)		 9°C
(48°F)		 15°C
(59°F)		 21°C
(70°F)		 25°C
(77°F)		 25°C
(77°F)		 22°C
(71°F)		 16°C
(60°F)		 8°C
(46°F)		 3°C
(38°F)
Daily mean -2°C
(29°F)		 -2°C
(29°F)		 1°C
(35°F)		 6°C
(43°F)		 12°C
(54°F)		 18°C
(65°F)		 23°C
(73°F)		 22°C
(72°F)		 19°C
(66°F)		 13°C
(56°F)		 5°C
(42°F)		 1°C
(35°F)
Average low -4°C
(24°F)		 -4°C
(25°F)		 -1°C
(30°F)		 4°C
(39°F)		 9°C
(49°F)		 16°C
(60°F)		 20°C
(68°F)		 20°C
(68°F)		 16°C
(62°F)		 11°C
(51°F)		 3°C
(38°F)		 -1°C
(31°F)
Mean minimum -14°C
(8°F)		 -13°C
(9°F)		 -9°C
(16°F)		 -1°C
(30°F)		 3°C
(39°F)		 11°C
(52°F)		 17°C
(63°F)		 16°C
(61°F)		 12°C
(53°F)		 5°C
(41°F)		 -5°C
(24°F)		 -8°C
(18°F)
Minimum -18°C
(-1°F)		 -19°C
(-2°F)		 -13°C
(9°F)		 -3°C
(27°F)		 0°C
(33°F)		 8°C
(47°F)		 16°C
(61°F)		 15°C
(59°F)		 9°C
(48°F)		 3°C
(37°F)		 -8°C
(18°F)		 -17°C
(2°F)

Compare climate in St. Catharines with other places

Compare temperature, precipitation, sunshine, UV index in St. Catharines, Ontario, Canada with other places around the world.

Monthly average precipitation in St. Catharines, Ontario, Canada §

St. Catharines usually has the most precipitation in April, July and October, with an average of 13 rainy days and 117 mm (4.6 inches) of precipitation per month.The driest months in St. Catharines are January, March and September. On average, 73 mm (2.9 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in St. Catharines, Ontario, Canada.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average precipitation mm (inches) 77 (3.0) 86 (3.4) 71 (2.8) 119 (4.7) 101 (4.0) 82 (3.2) 106 (4.2) 80 (3.1) 69 (2.7) 126 (4.9) 86 (3.4) 86 (3.4)
Average precipitation days (≥ 1 mm) 10 13 10 13 13 10 12 12 9 15 11 13

Monthly sunshine hours in St. Catharines, Ontario, Canada §

The sunniest months in St. Catharines are June, July and August, when the sun shines an average of 11 hours 14 minutes a day.Least sunny months in St. Catharines: January, February and December receive an average of 4 hours 6 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in St. Catharines, Ontario, Canada.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean monthly sunshine hours 107 150 231 240 291 340 348 344 303 206 157 115
Mean daily daylight hours 9h 23m 10h 31m 11h 57m 13h 26m 14h 41m 15h 18m 14h 58m 13h 51m 12h 26m 10h 58m 9h 41m 9h 1m

Solar UV radiation in St. Catharines, Ontario, Canada §

St. Catharines experiences the highest level of ultraviolet (UV) radiation in May, June and August, when the maximum UV index can reach values of 9 - 10, which corresponds to the Very High category of sun exposure.January, November and December are in the Low / Moderate exposure category. In these months, the maximum values of the UV index do not exceed 3. For more detailed information, check out our hourly St. Catharines UV Index data.

Average daily maximum UV levels by month for St. Catharines, Ontario, Canada.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2022 to January 2023.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
UV Index (month maximum) 2 4 5 8 9 10 9 9 7 5 3 2