|April long term rainfall averages.|
The April recorded rainfall for McLaren Vale was approximately equal to the median rainfall.
This is compared to the long-term average of 40.1 mm on 8 rain days, and the median rainfall of 33.6 mm. By comparison, during April 2011, 13.6 mm was recorded. April 2010 was the last April in Adelaide with above average rainfall with 49.6mm.
Most of the month saw only small rainfall totals from weak cold frontal systems. Much of the rainfall observed for the month came from a series of cold fronts around a strong cold air mass in the third week of the month. This event also produced significant totals in the Adelaide Hills in the persistent moist westerly airstream, resulting in totals for the month in this region being closer to average than on the plains where totals were typically only 50% of average.
Rainfall totals for April 2012 across the plains typically were ranged from 15 to 25mm with higher totals in the 25 to 50mm range in the Adelaide Hills. The wettest location for the month was Mount Barker where 49.2mm was recorded for the month, most of that occurring on the 22nd and 23rd of the month.
Much of the month was very much warmer than average with maximum temperatures up to 6 degrees above average in the first week. Daytime temperatures remained about 2 to 3 °C above average for the month as a whole, despite a cooler burst of weather near months end associated with a strong cold air mass and sequence of cold fronts.