March: 10-15c high, -5c-0c low, mostly clear skies, some snow, some showers.
April: 15-20c high, 0c low, mostly clear again, less snow, increasing heat.
May: 20-25c high, 0-10c low, mostly hot by day, cold by night, some t-storms/showers.
June: 25-30c high, 5-15c low, very hot most days, cooler by the evening.
July: 25-35c high, 10-15c low, hot and dry days and warm evenings.
August: 20-30c high, 10-15c low, hot still, but increasingly humid/erratic, plenty of t-storms/storms.
September: 15-25c high, 5-15c low, increasingly cool, plenty of rain/wind/storms/t-storms with a few sunny days.
October: 5-15c high, -5c-0c low, increasingly cold, first snows, plenty of storms/wind.
November-December: very cold, increasingly sub-zero highs, ice days, heavy snow/storms, little sun.
January-February: still cold, though in Feb less so, increasing sun.
Basically anything with plenty of snow/cold/storms between September and January; and hot and sunny between May and August. And a fair few t-storms throughout the year.