Canberra in March 2012: 3rd wettest March on record

  • 3rd wettest March on record, wettest since 1989.
  • Third wettest 5-day rain event on record.
  • 5th coldest March days on record, coldest since 1993.

Rainfall

Canberra Airport recorded 198 mm of rain during March, almost four times the historical average of 50.7 mm. This is the 3rd wettest March on record for Canberra Airport, as well as the wettest since 1989 at the Airport, the Botanical Gardens, and Tharwa General Store. The rain fell over 15 rain days, twice the March average and the second highest on record, following 18 days in 1956. Two days exceeded 50 mm; this has only occurred once for any month since the site opened in 1939, during March 1950.

The majority of the rain fell during the first five days of the month, as a low pressure trough brought widespread heavy rainfall to southern NSW and the ACT. Canberra Airport recorded 163.2 mm between the 1st and 5th, with similar totals only recorded two times before in any month, between 11-15 March 1989 and 18-22 March 1950. Daily falls at the Airport were as high as 62 mm on the 4th, reaching 93 mm at Tharwa General Store and 107.6 mm at Mt Ginini. This was the wettest single day in Canberra since December 2010.

The heavy rain in late February and early March resulted in minor to moderate flooding, road closures, and some flash flooding in the ACT, with 941 Requests for Assistance to the ACT SES. For further information on the impacts of the heavy rain and flooding across southeastern Australia please see Special Climate Statement 39.

Temperature

The average maximum temperature at Canberra Airport during March was 22.1 °C, 2.4 °C below the historical average. This is the coldest March in Canberra since 1993, and the equal 5th coolest on record. The cool days were particularly driven by overcast conditions associated with the rain event at the beginning of the Month, with two consecutive days reaching just 16.6 °C on the 2nd and 3rd; the last spell this cold was during March 1994.

The warmest day during the month reached just 27.2 °C on the 14th; the last March with no warmer days was also in 1994, with a maximum of 27.0 °C. Only 6 days reached 25 °C during the month, well below the March average of 14 days and the fewest since 1994.

In comparison, the average minimum temperature during March was 0.6 °C below average at 10.1 °C. Only one night dropped below 5 °C, normal for March, reaching 2.2 °C on the 25th, the coldest March night since 2001. The mean temperature for March was consequently 16.1 °C, 1.5 °C below average and the coolest March since 1994.

Wind

The prevailing wind direction at Canberra Airport during March was northwesterly, with 48% of 3pm winds between NNW and WNW, normal for March. Four strong wind days were reported at Canberra Airport, with minor damage associated with windy conditions on the 7th. The maximum wind gust at Canberra Airport was 65 km/hr on the 1st, with the strongest winds anywhere in the state reaching 81 km/hr at Mt Ginini AWS on the 23rd.

Other phenomena

Canberra Airport recorded an average of 6.6 hours of bright sunshine during March, well below the historical average of 8.1 hours but similar to March 2011 (6.5 hours). Conditions were particularly cloudy at the start of the month, with seven consecutive days of completely overcast conditions between February 27 and March 4. This is only the second time on record with such a long period of overcast conditions, following seven overcast days 31 July - 6 August 1952.

There were no thunderstorms reported at Canberra Airport, below the March average of two storms, with four storms reported anywhere in the ACT.

Further information

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Extremes in March 2012
Hottest day 27.3 °C at Tuggeranong (Isabella Plains) AWS on the 14th
Warmest days on average 22.1 °C at Canberra Airport
22.1 °C at Tuggeranong (Isabella Plains) AWS
Coolest days on average 13.4 °C at Mount Ginini AWS
Coldest day 4.7 °C at Mount Ginini AWS on the 23rd
Coldest night -1.0 °C at Mount Ginini AWS on the 24th
Coolest nights on average 5.6 °C at Mount Ginini AWS
Warmest nights on average 10.5 °C at Tidbinbilla Nature Reserve
10.5 °C at Tuggeranong (Isabella Plains) AWS
Warmest night 15.8 °C at Tuggeranong (Isabella Plains) AWS on the 17th
Warmest on average overall 16.3 °C at Tuggeranong (Isabella Plains) AWS
Coolest on average overall 9.5 °C at Mount Ginini AWS
Wettest overall 303.4 mm at Mount Ginini AWS
Wettest day 107.6 mm at Mount Ginini AWS on the 4th
Highest wind gust 81 km/h at Mount Ginini AWS on the 23rd

Summary statistics for March 2012
Maximum temperatures
for March
(°C)
Minimum temperatures
for March
(°C)
Rainfall
for March
(millimetres)
Mean for
March
2012
Diff
from
average
Highest for
March
2012
Mean for
March
2012
Diff
from
average
Lowest for
March
2012
Total for
March
2012
Average
for
March
Rank of
March
2012
Fraction of
March
average
Canberra Airport 22.1 -2.4 27.2 14th 10.1 -0.6 2.2 25th 198.0 50.7 v high 391%
Mount Ginini AWS 13.4   18.3 14th 5.6   -1.0 24th 303.4
Tidbinbilla Nature Reserve 21.6 -2.1 25.5 31st 10.5 +0.5 4.6 25th 86.9 67.6 high 129%
Tuggeranong (Isabella Plains) AWS 22.1   27.3 14th 10.5   2.6 25th 269.6

Notes

As of March 2010, the official station for Canberra is 70351 'Canberra Airport'. Averages from the previous site, 70014 Canberra Airport, are used for comparisons.

A Monthly Climate Summary is prepared to list the main features of the weather in Canberra 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 9 am on Monday 2 April 2012. 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.

Further information

Media
(03) 9669 4057
Enquiries