Adelaide: Climate and water
For the water account period 01 July 2022 – 30 June 2023
- Total annual rainfall was above average for the second consecutive year, with 2022-23 being the region's 12th-wettest year on record.
- The 2022-23 spring was the second wettest on record and included the region's wettest November (1900-2023).
- Soil moisture in the root zone (0-1 m depth) was above average across most of the region and very much above average in the central and southern regions.
- Total annual flow in the North Para River at Yaldara was above average, with monthly record streamflows during November 2022.
For further information on the region's climate and water conditions during the 2022-23 year scroll down this page or click on the links below:
About the region
- The Adelaide region has a Mediterranean climate, characterised with cold to mild wet winters and warm to hot dry summers.
- Most of the region's rainfall occurs from mid autumn to mid spring (April to October), which coincides with southern Australia's wet season. Rainfall can be unreliable and infrequent from late spring to early autumn (November to March).
- Streamflows in the region's rivers generally reflects the distribution of rainfall throughout the year. Higher streamflows and storage inflows occur during the winter months (June to August), while streamflows can cease to flow during the dry summer months (December to February).
Climate conditions
Rainfall
Figure C1 Annual and monthly rainfall deciles for the Adelaide region during the 2022–23 year
- Total area-averaged rainfall for the 2022-23 year was 779 mm, 24% above the mean value of 629 mm. It was the region's second consecutive year of above average rainfall, as well as the region's twelfth wettest year since records began in 1900.
- In August 2022, a negative Indian Ocean Dipole event was declared and remained active through to December 2022. A negative Indian Ocean Dipole generally increases the chances of above average winter to spring rainfall for the region.
- While rainfall during July 2022 was very much below average across most of the region, spring rainfall was the second wettest on record and up to double the seasonal average in some areas.
- A surface trough associated with a low-pressure system brought thunderstorms and widespread rainfall to the region during the second week of November 2022, resulting in the region's wettest November on record, with many sites recording their highest total November rainfall for at least 20 years.
- Total area-averaged summer rainfall was 68% below the seasonal average.
- Rainfall was average to above average throughout autumn and several active cold fronts passing over the region led to above average rainfall for June 2023.
- More information on Australia's climate and water over the 2022-23 year can be found at: Financial year climate and water statement 2022-23.
Figure C2 Total monthly rainfall for the Adelaide region during the 2022–23 year compared with the average and percentiles for the region
- July 2022 was the only month which recorded rainfall below the 10th percentile.
- Rainfall from August to November 2022 was above average, with November 2022 the wettest on record for the month.
- Rainfall throughout summer was a bit below average, but was above average for the remainder of 2022-23.
Actual evapotranspiration
Figure C3 Annual and monthly actual evapotranspiration deciles for the Adelaide region during the 2022–23 year
- Total area-averaged actual evapotranspiration for the 2022-23 year was above average across the entire region, with areas in the south, north, and the metropolitan areas of Adelaide recording very much above average evapotranspiration.
- Evapotranspiration was predominantly below average during July 2022 following the region's seventh-driest July on record.
- Despite increased rainfall, mean maximum temperatures were cooler than average during September 2022 and October 2022 and evapotranspiration was below average.
- However, record November rain significantly increased the water availability across the region and consequently evapotranspiration remained above average during November 2022 and throughout summer.
- From March onwards, evapotranspiration was average to above average throughout most of the region and very much above average in June 2023.
Soil moisture
Figure C4 Annual and monthly soil moisture deciles for the Adelaide region during the 2022–23 year
- Soil moisture in the root zone (0–1 m depth) for the 2022-23 year was above average across most of the region, with areas of very much above average soil moisture in the central and southern regions.
- Despite July 2022 being notably dry, soil moisture was predominantly average across the region sustained by higher soil moisture in June 2022.
- Following higher rainfall totals in spring, there was an increase in soil moisture from August 2022 through to November 2022.
- With the record November rainfall in 2022, the soil moisture was very much above average across the entire region with much of the eastern perimeter recording highest on record.
- Soil moisture remained predominantly above average during December 2022. However, following the lack of rainfall, the soil moisture returned to average for most of the region towards the backend of summer.
- From March 2023 onwards, the soil moisture was mostly average to above average, reflecting the above-average rainfall that fell during these months. Some areas of the northeast had below-average soil moisture during May 2023, but returned to average by June 2023.
- More information on soil moisture distribution across the Adelaide region is available in the Australian Water Outlook.
Streamflow responses
Figure C5 Key flow gauging stations
along the main rivers within the Adelaide region
- Onkaparinga River provides the major inflows into Mount Bold Reservoir—the region's largest storage.
- Flow along the North Para River is unregulated and not influenced by diversions for consumptive use.
Figure C6 Total monthly flow for major rivers in the Adelaide region during the 2022–23 year compared with the average and percentiles
- Total annual flow in the North Para River at Yaldara (Station A5050502) was above average during the 2022-23 year at 18.2 GL compared to the average anual flow volume of 12.6 GL.
- Following record November rainfall, streamflow for North Para River at Yaldara was the highest recorded flow for that month and remained above the 90th percentile during December 2022.
- With below average rainfall during summer, streamflow returned to lower flows typical of the seasonal flow regime.
- Streamflows remained low but near average throughout autumn and into winter as is normal during this time of the year.
Note: No streamflow data was available for the North Para River at Yaldara during August 2022 and September 2022.