Monthly Historical AveragesHarriston, ON
Average Temperature
High
18°
Feels 18
Low
7°
Feels 5
Average Precipitation
10 Days
46.3mm
0.1cm
Content continues below
Daily Historical Averages
S
M
T
W
T
F
S
ForecastSaturday, May 9, 2026
Day
15°Feels 14
Wind
34 km/h S
Gust
51 km/h
Humidity
57%
P.O.P
90%
Rain
2-4 mm
Night
1°Feels -2
Wind
32 km/h W
Gust
48 km/h
Humidity
93%
P.O.P
60%
Rain
<1 mm
Historical AveragesMay 9
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity