Wednesday, 1 April 2009 - Monthly Climate Summary for Canberra rainfall extremes - Product code IDCKGC25x0

Canberra has warm, dry and sunny March

Summary

Conditions experienced in Canberra during March were similar to February with above average temperatures and well below average rainfall.

  • Well below average rainfall
  • Warm days with well above average maximum temperatures (ranks 10th warmest March on record)
  • Mild nights with above average minimum temperatures
  • Very low average 3pm humidity
  • Well above average sunshine

An archive of previous monthly summaries for Canberra rainfall extremes is also available, as are summaries for other states and many other climate summaries and diagnostics.

Rainfall

Following a dry February, very dry conditions continued throughout March with well below average rainfall over the ACT. Canberra Airport recorded a total of only 9.8 mm, well below the March average1 of 50.8 mm. It was the driest March for 5 years. The driest March on record was in 1954 with 1.3 mm. It is also Canberra's driest start to the year since 1998 with only 68.8 mm since 1st January. There were only 3 rain days during the month compared to the historic average of 7 rain days. Virtually the entire month's rain occurred during a thunderstorm on the 14th. A prevailing high pressure ridge over NSW for most of the month was generally responsible for the dry, stable weather in the ACT.

Bendora Dam had the Territory's highest March total of 49 mm while Gordon (Tuggeranong) recorded the lowest total of only 5.2 mm. The wettest day was 39.8 mm at Bendora Dam on the 5th and 23.2 mm at Watson on the 28th.

Temperatures

March was a very warm month in the ACT with well above average maximum temperatures. Canberra Airport recorded an average maximum of 26.7°C, which is 2.2°C above the historical average of 24.5°C. This ranks as the 10th warmest March since records commenced 70 years ago in 1939. There were 5 hot days (temperature exceeding 30°C) during the month compared to the March historic average of 3 hot days. A cold front on the 15th produced the only significant cool day in the ACT, reaching only 21°C.

The warm conditions were partly due to slow moving high pressure systems in the Tasman Sea directing generally northerly winds over NSW and the ACT and tended to deflect any cool changes to the southeast.

Overnight temperatures were also very mild. The average minimum temperature at Canberra Airport was 11.8°C which is 1.1°C above the historic average. Early in the month there were 4 consecutive nights with minimum temperatures exceeding 15°C. The minimum temperature on the warmest night was 17.1°C on the 13th.

Temperature extremes at Canberra Airport ranged from a high of 31.9°C on the 24th to an overnight low of 3.9°C on the 17th. The lowest temperature in the ACT was 0.8°C at Mount Ginini AWS on the 16th following a cold front the day before.

Wind

NE - NW winds prevailed over the ACT during March with frequencies over 70% during the afternoon compared to the normal frequency of 45% at this time. Mostly light winds prevailed during the month with no windy days recorded, compared to the historical average of one windy day for March. Early autumn in Canberra is normally the time of year with the lightest winds. The highest wind gust of 59 km/h at Canberra Airport on the 25th and 26th was associated with the passage of a low pressure trough.

Other phenomena

Dry atmospheric conditions prevailed in the ACT during March with the average humidity at 3pm only 29%, the lowest at this time since 1998. This compares to the normal humidity of 42% at this time. On the 29th, the humidity fell to a very dry 12%, one of the lowest values ever recorded in March. Generally sunny conditions prevailed in Canberra during the month. Sunshine averaged 8.9 hours per day which is well above the historic average of 8.1 hours per day. There was only one thunderstorm reported at Canberra Airport (on the 14th) with the associated showers comprising nearly the entire month's rainfall.

Further information

Mike De Salis
Climate Officer
NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au

Extremes for the ACT

Hottest day
Highest temperature
31.9°C at Canberra Airport on the 24th
Warmest days on average
Highest mean daily maximum temperature
26.7°C at Canberra Airport
Coolest days on average
Lowest mean daily maximum temperature
17.3°C at Mount Ginini AWS
26.6°C at Tuggeranong AWS
Coldest day
Lowest daily maximum temperature
21.2°C at Canberra Airport on the 15th
11.1°C at Mount Ginini AWS on the 5th
Coldest night
Lowest temperature
0.8°C at Mount Ginini AWS on the 16th
3.0°C at Tidbinbilla Nature Reserve on the 7th
3.7°C at Tuggeranong AWS on the 17th
Coolest nights on average
Lowest mean daily minimum temperature
7.0°C at Mount Ginini AWS
11.7°C at Tuggeranong AWS
Warmest nights on average
Highest mean daily minimum temperature
11.8°C at Canberra Airport
Warmest night
Highest daily minimum temperature
17.3°C at Tuggeranong AWS on the 3rd and the 13th
Wettest overall
Highest total rainfall
49.0 mm at Bendora Dam
36.2 mm at Corin Dam
29.4 mm at Watson
Driest overall
Lowest total rainfall
5.2 mm at Gordon (Tuggeranong)
Wettest day
Highest daily rainfall
39.8 mm at Bendora Dam on the 5th
23.2 mm at Watson on the 28th
Highest wind gust
59 km/h at Canberra Airport on the 25th and the 26th

Records

Nil recorded


Summaries for the ACT

This table is very wide and may not fit if printed.

Summary statistics for March 2009
Maximum temperatures
for March
(°C)
Minimum temperatures
for March
(°C)
Rainfall
for March
(millimetres)
Mean for
March
2009
Diff
from
average
Highest for
March
2009
Mean for
March
2009
Diff
from
average
Lowest for
March
2009
Total for
March
2009
Average
for
March
Rank of
March
2009
Fraction of
March
average
Canberra Airport 26.7 +2.2 31.9 24th 11.8 +1.1 3.9 17th 9.8 50.2 low 20%
Tuggeranong 26.6 +1.0 31.7 24th 11.7 +0.6 3.7 17th 8.6 30.5 low 28%
Mount Ginini AWS 17.3   21.0 24th 7.0   0.8 5th 16.0

Notes

This statement has been prepared based on information available at noon on Wednesday 1 April 2009. 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 10 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

Mike De Salis
Climate Officer
NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au