| Thornhill normally receives about 358mm of rain per year, with most rainfall occuring mainly during summer. The chart below (lower left) shows the average rainfall values for Thornhill per month. It receives the lowest rainfall (4mm) in July and the highest (64mm) in March. The monthly distribution of average daily maximum temperatures (centre chart below) shows that the average midday temperatures for Thornhill range from 16°C in June to 27.6°C in January. The region is the coldest during July when the mercury drops to 1.5°C on average during the night. Consult the chart below (lower right) for an indication of the monthly variation of average minimum daily temperatures. |
| Move mouse over chart bars for monthly values |
|
Average rainfall (mm)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
![]() |
|
|
|
|
J
|
|
F
|
|
M
|
|
A
|
|
M
|
|
J
|
|
J
|
|
A
|
|
S
|
|
O
|
|
N
|
|
D
|
|
|
|
|
|
|
Average midday temperature (°C)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
![]() |
|
|
|
|
J
|
|
F
|
|
M
|
|
A
|
|
M
|
|
J
|
|
J
|
|
A
|
|
S
|
|
O
|
|
N
|
|
D
|
|
|
|
|
|
|
Average night-time temperature (°C)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
![]() |
|
|
|
|
J
|
|
F
|
|
M
|
|
A
|
|
M
|
|
J
|
|
J
|
|
A
|
|
S
|
|
O
|
|
N
|
|
D
|
|
|
|
|
|
|
