nomadseason

Monthly climate in Harriston, Canada

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Harriston features a humid continental climate (Dfb). Temperatures typically range between -6 °C (21 °F) and 20 °C (69 °F) through the year, but rarely can drop to -26 °C (-15 °F) or can rise to as high as 32 °C (90 °F). The average annual precipitation amounts to about 1128 mm (44.4 inches) and receives 160 rainy days on the 1 mm (0.04 inches) threshold annually. Harriston enjoys an average of 2704 hours of sunshine throughout the year, and daylight varies from 8 hours 56 minutes to 15 hours 24 minutes per day.

Monthly average temperatures in Harriston, Canada

The warmest months in Harriston are June, July and August, with daily mean temperatures ranging from 18 to 20 °C (64 - 69 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -6 to -3 °C (21 - 28 °F) throughout the day. On average each year, Harriston experiences 38 days above 25 °C (77.0 °F) and 143 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Harriston. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum11°C
(52°F)		15°C
(59°F)		19°C
(67°F)		25°C
(78°F)		30°C
(87°F)		31°C
(89°F)		32°C
(90°F)		30°C
(87°F)		31°C
(87°F)		27°C
(80°F)		23°C
(73°F)		16°C
(60°F)
Mean maximum6°C
(44°F)		10°C
(51°F)		16°C
(60°F)		22°C
(71°F)		29°C
(84°F)		30°C
(86°F)		30°C
(86°F)		29°C
(84°F)		28°C
(82°F)		25°C
(76°F)		15°C
(59°F)		10°C
(51°F)
Average high-3°C
(27°F)		-1°C
(30°F)		3°C
(39°F)		10°C
(50°F)		17°C
(63°F)		22°C
(73°F)		25°C
(77°F)		24°C
(75°F)		20°C
(69°F)		13°C
(56°F)		5°C
(41°F)		0°C
(33°F)
Daily mean-6°C
(21°F)		-6°C
(22°F)		-1°C
(30°F)		5°C
(41°F)		12°C
(54°F)		18°C
(64°F)		20°C
(69°F)		19°C
(67°F)		15°C
(60°F)		9°C
(49°F)		1°C
(35°F)		-3°C
(28°F)
Average low-10°C
(15°F)		-10°C
(15°F)		-6°C
(22°F)		0°C
(33°F)		7°C
(45°F)		12°C
(54°F)		15°C
(60°F)		14°C
(58°F)		11°C
(51°F)		5°C
(42°F)		-2°C
(29°F)		-5°C
(22°F)
Mean minimum-21°C
(-6°F)		-21°C
(-5°F)		-17°C
(1°F)		-6°C
(22°F)		-2°C
(29°F)		7°C
(45°F)		10°C
(49°F)		9°C
(48°F)		3°C
(38°F)		-2°C
(28°F)		-14°C
(8°F)		-16°C
(4°F)
Minimum-25°C
(-12°F)		-25°C
(-13°F)		-21°C
(-5°F)		-9°C
(17°F)		-4°C
(25°F)		3°C
(38°F)		8°C
(47°F)		5°C
(42°F)		-1°C
(30°F)		-4°C
(26°F)		-19°C
(-1°F)		-26°C
(-15°F)

Compare climate in Harriston with other places

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

Monthly average precipitation in Harriston, Canada

Harriston usually has the most precipitation in April, August and October, with an average of 14 rainy days and 110 mm (4.3 inches) of precipitation per month. The driest months in Harriston are January, March and December. On average, 76 mm (3.0 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Harriston. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)76 (3.0)83 (3.3)70 (2.8)107 (4.2)103 (4.1)106 (4.2)89 (3.5)110 (4.3)94 (3.7)111 (4.4)95 (3.8)83 (3.2)
Average precipitation days (≥ 1 mm)131511141211121311151617

Monthly sunshine hours in Harriston, Canada

The sunniest months in Harriston are June, July and August, when the sun shines an average of 11 hours 2 minutes a day. Least sunny months in Harriston: January, November and December receive an average of 3 hours 23 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Harriston. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours8113422123429633335033129319513297
Mean daily daylight hours9h 18m10h 29m11h 57m13h 28m14h 45m15h 24m15h 3m13h 54m12h 27m10h 56m9h 37m8h 56m

Solar UV radiation in Harriston, Canada

Harriston 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 Harriston UV Index data.

Average daily maximum UV levels by month for Harriston. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)2458910997532