Adelaide Metro & Hills in July 2013: Warm and Wet

  • Above average monthly rainfall for most locations with Adelaide having its wettest July in 18 years (since 1995).
  • Above average day and night temperatures, with new record warm nights across the Plains.

Rainfall

Adelaide (Kent Town) received 119.2 mm of rainfall on 17 rain days throughout July 2013, well above the long term average July rainfall of 74.7 mm, and the median of 68.8 mm, typically received on 16 rain days. The well above normal rainfall results in the wettest July since 1995. By comparison, the record highest July rainfall for Adelaide was in 1986 with 159.8 mm recorded for the month.

The wettest days during July 2013 across the Adelaide and Hills region occurred between the 5th and 8th, between the 13th and 15th and later between the 18th and 23rd. Adelaide (Kent Town) observed nearly half of the monthly total in the latter period owing to the passage of a deep low pressure system located to the south of the State, around which a frontal rainband extended across the state.

Rainfall totals across the Adelaide region typically ranged from 60 to 110mm across the Adelaide Plains, with higher totals in excess of 150 mm observed in the Adelaide Hills. The wettest location for the month was at Mount Lofty in the Adelaide Hills where 220.4 mm was observed, more than 100 mm of that occurring between the 18th and 22nd of the month.

Note that the Adelaide official climate rainfall record is taken from the manually observed 203mm rain gauge at the Kent Town site in Adelaide. These figures may differ from totals on some Bureau of Meteorology web pages as these may be from automatic tipping bucket rain gauge readings.

Temperature

Both day and night time temperatures were above average across the Adelaide region, particularly throughout the period between the 10th and 18th and later in the month between the 26th and 28th. With respect to the above average day time temperatures, the relatively warm spells were due to high pressure systems located to the east of South Australia  directing moderate to fresh northerly winds across the State. The warmest nights were between the 13th and 18th and between the 28th and 31st owing to increased cloud cover associated with the passage of low pressure troughs.

The mean temperature for the month (the combination of maximum and minimum temperature) was slightly above average with 12.7 °C for Adelaide (Kent Town); by comparison July 2012 observed a mean monthly temperature of 11.6 °C.

The warmest day occurred on the 28th as light to moderate northerly winds ahead of the low pressure system resulted in above temperatures across the region. The coldest day was observed on the 20th as a deep low pressure located to the southeast of the Mount Gambier directed a cool unstable southerly airstream across the region.

The average maximum temperature recorded at Adelaide (Kent Town) for July 2013 was 16.3 °C, 1.0°C above the long-term mean maximum temperature, the warmest July since 2002. In comparison, July 2012 was cooler with an average of 15.3 °C.  The record highest July monthly maximum in Adelaide was 17.5°C, set in 1957 at the West Terrace site.

The hottest day across the Adelaide and Hills region was reported at Kent Town with a maximum of 20.8 °C on the 28th. The coldest day in the region was observed at Mount Lofty on the 20th when the maximum reached only 5.5 °C.

Minimum temperatures were between 1 to 2 °C warmer than average throughout the month. The mean minimum temperature for July 2013 at Adelaide (Kent Town) was 9.1 °C, 1.6 °C warmer than normal and the warmest since 1975 when overnight minimum temperatures averaged 9.4 °C. By comparison, July 2012 saw minimum temperatures for the month averaging 7.8 °C.

The coldest minimum temperature recorded during July 2013 in the Adelaide and Hills region was 0.9 °C on the 20th at Mount Lofty, with the coolest nights on average also recorded at Mount Lofty. The warmest night was 14.8 °C at Kent Town on the 28th. Noarlunga observed the warmest nights overall with average 9.8 °C

Please Note: this information is provided on the last working day of the month; naturally, finalised figures cannot be provided until the first working day of the following month, when a more complete release will be issued.

Some sites had their highest July mean daily minimum temperature on record. Some sites had their highest July mean daily minimum temperature for at least 20 years.

Further information

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Extremes in July 2013
Hottest day 20.8 °C at Adelaide (Kent Town) on the 28th
Warmest days on average 16.3 °C at Adelaide (Kent Town)
Coolest days on average 10.4 °C at Mount Lofty
Coldest day 5.5 °C at Mount Lofty on the 20th
Coldest night 0.9 °C at Mount Lofty on the 20th
Coolest nights on average 6.0 °C at Mount Lofty
Warmest nights on average 9.8 °C at Noarlunga
Warmest night 14.3 °C at Adelaide (Kent Town) on the 28th
Warmest on average overall 12.7 °C at Adelaide (Kent Town)
12.7 °C at Noarlunga
Coolest on average overall 8.3 °C at Mount Lofty
Wettest overall 220.4 mm at Mount Lofty
Driest overall 73.4 mm at Parafield Airport
Wettest day 34.0 mm at Mount Barker on the 19th
Highest wind gust 78 km/h at Mount Lofty on the 18th
78 km/h at Noarlunga on the 18th

Record highest July mean daily minimum temperature
Mean daily minimum
temperature
for July 2013 (°C)
Previous warmest
for July
Years of
record
Average for
July
Adelaide Airport 8.8 8.5 in 2009 58 7.0
Edinburgh RAAF 7.6 7.4 in 1995 40 6.0
Adelaide (Kent Town) 9.1 9.0 in 2009 36 7.5

Highest July mean daily minimum temperature for at least 20 years
Mean daily minimum
temperature
for July 2013 (°C)
Most recent July
at least this warm
Years since
warmer
Average for
July
Mount Barker 6.7 =6.7 in 1930 83 4.5
Parafield Airport 7.8 8.2 in 1990 23 6.3



Summary statistics for July 2013
Maximum temperatures
for July
(°C)
Minimum temperatures
for July
(°C)
Rainfall
for July
(millimetres)
Mean for
July
2013
Diff
from
average
Highest for
July
2013
Mean for
July
2013
Diff
from
average
Lowest for
July
2013
Total for
July
2013
Average
for
July
Rank of
July
2013
Fraction of
July
average
Adelaide (Kent Town) 16.3 +1.0 20.8 28th 9.1 +1.6 4.1 9th 119.2 74.7 v high 160%
Adelaide Airport 16.0 +1.1 19.7 17th 8.8 +1.8 3.2 9th 92.2 59.4 high 155%
Edinburgh RAAF 16.0 +0.7 19.9 28th 7.6 +1.6 2.5 9th 84.2 53.0 high 159%
Mount Barker 13.6 +0.7 19.1 28th 6.7 +2.2 1.2 9th 191.3 106.6 v high 179%
Mount Lofty 10.4   15.6 27th 6.0   0.9 20th 220.4
Noarlunga 15.6   20.0 17th 9.8   5.5 20th 107.4
Parafield Airport 16.2 +1.1 20.4 28th 7.8 +1.5 2.3 9th 73.4 58.5 high 125%

Notes

A Monthly Climate Summary is prepared to list the main features of the weather in Adelaide Metro & Hills using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 10 am on Wednesday 31 July 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 20 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.

Further information

Media
(03) 9669 4057
Enquiries