Rainfall across the Adelaide region was generally below average for the 2012–13 year, with the central and northern parts experiencing rainfall very much below average (Figure C1). The total area-averaged rainfall over the Adelaide region during the 2012–13 year was 443 mm, which is below the long-term area-averaged rainfall of 575 mm (based on the 1900–2013 period).
The 2012–13 conditions represent a decrease in rainfall compared to the 2011–12 year (see the 2012 Account), when rainfall was close to average. The below average rainfall in 2012–13 contributed to below average flows in the major river systems in the region (see Water overview ) as well as decreased inflows into the major water storages during the 2012–13 year (see the Surface water section of the 'Water resources and systems' note).
Figure C1 Map of annual rainfall deciles for the Adelaide region during the 2012–13 year
Annual rainfall ranged from more than 700 mm in areas in southern parts of the region, to less than 400 mm in the north (Figure C2).
Figure C2 Map of total annual rainfall for the Adelaide region during the 2012–13 year
Generally below-average rainfall was experienced across much of Australia during the 2012-13 year. There were no strong influences from large-scale climate drivers over the 2012–13 year. Conditions in the Pacific Ocean were neutral and a negative Indian Ocean Dipole event developed during winter 2013 (at the end of the 2012–13 year).
The area-averaged monthly rainfall was below the long-term average for most months during the 2012–13 year, with the exception of June 2013 (Figure C3). June 2013 was the wettest month of the 2012–13 year in the Adelaide region.
Figure C3 Graph of total monthly rainfall for the Adelaide region during the 2012–13 year compared with the long-term average and percentiles for the region
The total annual area-averaged evapotranspiration over the Adelaide region during the 2012–13 year was 473 mm by the Australian Water Resource Assessment (AWRA v3.0) model.
Evapotranspiration across the Adelaide region was generally below average for the 2012–13 year (Figure C4). Despite very much above average temperatures (see Temperature), evapotranspiration was limited by below average rainfall (see Rainfall).
Evapotranspiration was greater than rainfall in the Adelaide region during the 2012–13 year. Evapotranspiration may exceed rainfall when soil moisture levels are higher at the start, than at the end of a reporting period. This is consistent with above average rainfall conditions observed at the end of the 2011–12 year in the Adelaide region (refer to 2012 Account for further information), in particular June 2012 was the wettest June since June 2005, contributing to high soil moisture levels.
Figure C4 Map of annual evapotranspiration deciles for the Adelaide region during the 2012–13 year
Evapotranspiration was highest along the Mount Lofty Ranges ridge in the eastern part of the region and lowest in the lower elevation areas along the western part of the region (Figure C5).
Figure C5 Map of total annual evapotranspiration for the Adelaide region during the 2012–13 year
The long term area-averaged evapotranspiration was calculated to be 562 mm using long term data records from July 1911–June 2012 using AWRA v2.0 model with standard grids.
The entire Adelaide region experienced mean temperatures above the long-term average during the 2012–13 year (Figure C6).
Figure C6 Map of annual mean temperature deciles for the Adelaide region during the 2012–13 year
Annual mean temperatures across the region were generally above 14 °C (Figure C7). Coastal and western parts were warmer than the east of the region.
Figure C7 Map of annual mean temperature for the Adelaide region during the 2012–13 year
Monthly mean temperatures for the Adelaide region were above the long-term average for all months during the 2012–13 year, with the exception of August 2012 (Figure C8). Three months (November 2012, March and May 2013) ranked above the 90th percentile, with the Adelaide region experiencing its second-warmest May on record in 2013.
Figure C8 Graph of monthly mean temperature for the Adelaide region during the 2012–13 year compared with the long-term average and percentiles for the region