Adelaide Metro & Hills in April 2013: A warm and mainly dry month

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.
  • After a drier start, close to average rainfall and numbers of days of rainfall.
  • Temperatures were 1oC above average.
  • The first half of the month was significantly hotter than average, and the month ended with above average numbers of hot days.

Rainfall

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 vigorous cold fronts and 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 air-stream.

Rainfall totals for the month, across the Adelaide plains, typically ranged from 30 to 40 mm with higher totals of 50 to 70 mm in the Adelaide Hills. The wettest location for the month was Uraidla where 73.4 mm was recorded for the month, most of that occurring through the 21st to the 23rd of the month.

The April 2013 rainfall total at Adelaide (Kent Town) was 33.2 mm received on 8 rain days. This is compared to the long-term average of 39.6 mm on 8 rain days, and just exceeded the median rainfall of 33.1 mm. By comparison, during April 2012, 27.0 mm was recorded. April 2010 was the last April in Adelaide with above average rainfall with 49.6mm.

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

Temperature

The first half of the month was hotter than average by nearly 6 C, with much milder temperatures for the end of the month. For the month as a whole, daytime temperatures remained in excess of 1 C above average, despite a burst of cooler weather in the third week, associated with a strong cold air mass and sequence of cold fronts.

The mean maximum temperature recorded at the Adelaide (Kent Town) for April 2013 was 23.8 C, 1.2 C above the long-term mean maximum temperature of 22.7 C. In comparison, April 2012 saw average maximum temperatures of 24.2 C at Adelaide (Kent Town). The record highest April mean maximum in Adelaide is 26.9C set in 1923 at the West Terrace site.

During the month, Adelaide (Kent Town) recorded 3 days where the maximum temperature exceeded 30 C against the expected long term average of 2 days above 30C. The coldest day for Adelaide was the 21st when the maximum only reached 17.4 C. The warmest day was on the 12th when 32.1C was recorded for the maximum temperature. The coldest day overall was at Mount Lofty on the 23rd when the temperature reached 12.1 C.

Mean minimum temperatures were generally within 1C of the average this April across most of the Adelaide region. Some hills locations tended to be warmer than average by more than 1 C owing to above average cloud cover.

The mean minimum temperature for April 2013 at Adelaide (Kent Town) was 13.3 C, 0.9 C above the long term April average of 12.4 C. April 2012 recorded an average minimum temperature for the month of 12.6 C. The coldest minimum temperature recorded during April 2013, in the Adelaide and Hills area, was 4.3 C on the 19th at Mt Lofty, whilst the warmest night was 21.0C at Noarlunga on the 13th.

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Extremes in 1 April to 30 April 2013
Hottest day 32.1 °C at Adelaide (Kent Town) on the 12th
32.1 °C at Parafield Airport on the 12th
Warmest days on average 24.4 °C at Parafield Airport
Coolest days on average 18.1 °C at Mount Lofty
Coldest day 12.1 °C at Mount Lofty on the 21st
Coldest night 4.3 °C at Mount Lofty on the 19th
Coolest nights on average 9.8 °C at Mount Lofty
Warmest nights on average 14.1 °C at Noarlunga
Warmest night 21.0 °C at Noarlunga on the 13th
Warmest on average overall 18.6 °C at Adelaide (Kent Town)
Coolest on average overall 14.0 °C at Mount Lofty
Wettest overall 73.4 mm at Uraidla
Driest overall 5.1 mm at Adelaide (Torrens Island)
Wettest day 38.0 mm at Adelaide(Tea Tree Gully Council) on the 22nd
Highest wind gust 74 km/h at Mount Crawford (Mt Crawford AWS) on the 21st




Summary statistics for 1 April to 30 April 2013
Maximum temperatures
for 1 April
to 30 April
(°C)
Minimum temperatures
for 1 April
to 30 April
(°C)
Rainfall
for 1 April
to 30 April
(millimetres)
Mean for
1 April
to 30 April
2013
Diff
from
average
Highest for
1 April
to 30 April
2013
Mean for
1 April
to 30 April
2013
Diff
from
average
Lowest for
1 April
to 30 April
2013
Total for
1 April
to 30 April
2013
Average
for
1 April
to 30 April
Rank of
1 April
to 30 April
2013
Fraction of
1 April
to 30 April
average
Adelaide (Kent Town) 23.8 +1.1 32.1 12th 13.3 +0.9 9.1 20th 33.2 39.6 average 84%
Adelaide Airport 23.3 +1.1 31.3 12th 12.5 +0.7 7.5 20th 30.6 35.1 average 87%
Edinburgh RAAF 24.1 +1.0 32.0 12th 12.4 +0.5 6.9 20th 33.4 31.1 average 107%
Kuitpo Forest Reserve 20.2   28.5 12th 11.6   6.9 19th 31.4
Mount Barker 21.0 +0.2 30.0 12th 10.3 +1.7 5.6 17th 30.7 59.8 low 51%
Mount Crawford (Mt Crawford AWS) 20.4   28.6 12th 10.7   5.7 20th 54.4
Mount Lofty 18.1 +1.9 25.8 12th 9.8 -0.1 4.3 19th 67.4
Noarlunga 22.8   30.5 12th 14.1   10.0 16th 30.0
Parafield Airport 24.4 +1.7 32.1 12th 12.5 +0.6 6.5 20th 36.4 38.6 average 94%

Notes

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.

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 Tuesday 30 April 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