Record breaking heat in November for the ACT

  • Highest mean maximum temperature for Canberra and the ACT
  • Highest mean minimum temperature for Canberra and the ACT
  • Hottest November day on record at Canberra (38.9°C on the 20th)
  • Highest number of hot days (over 30 °C) on record for Canberra.
  • Below average rainfall.

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

Below average rainfall was recorded throughout the ACT for the month of November. Canberra Airport recorded a total of only 17.0 mm during the month, which is well below the historical average of 64.6 mm, and the 5th lowest for November since records commenced in 1939. This is also in contrast to the last two years, where November falls were above average. The rain fell on 6 days, compared the the average of 10 days. The biggest fall of 11.6 mm at the Airport was recorded in the 24 hours to 9am on the 27th, due to local thunderstorm activity. The highest fall in the Territory was recorded at Mt Ginini on the 1st of the month, also due to thunderstorm activity (on 31st October). Mt Ginini was the wettest overall location (despite missing some days of data), with a total of 62.0 mm recorded for November.

The majority of the falls in the ACT during November were due to thunderstorms associated with the passage of low pressure troughs.

See a map of rainfall deciles.

Temperatures

The ACT experienced extreme daytime temperatures for November, with large parts being on average 6°C warmer than usual. The mean maximum temperature for Canberra Airport was 29.0 °C, which is well above the historical average of 22.7 °C and the highest on record, exceeding the previous record of 28.7 °C (November 1982). It is the 8th consecutive November to record above average temperatures. The Airport recorded a significant 15 days during the month where the temperature exceeded 30 °C, which is also the highest on record (previous, 13 days in 1982). The Airport also recorded three days where the temperature exceeded 35 °C, which has only happened on two other occasions (in 1982 and 1997). The hottest day was reported on the 20th, where Canberra Airport reached 38.9 °C. This is equal to the hottest November day since records commenced (also occurred on 26th November 1997).

Minimum temperatures were also extreme, with average nighttime temperatures being up to 5 °C warmer than usual in some parts. The mean minimum temperature for Canberra Airport was 12.7 °C, which is 4.0 °C above the historical average of 8.7 °C, and the highest on record (previous record 11.8 °C in November 2007). It is the 6th consecutive year where November temperatures have been above average at this site.

Similar very high temperatures were experienced through much of New South Wales and the ACT. The high temperatures were mostly a result of a persistent high pressure system in the Tasman Sea, which restricted the passage of any significant cool changes and directed warm northwesterly airstream over the ACT. In addition, an El Niño event has matured in the equatorial Pacific Ocean. These events are usually (but not always) associated with above average temperatures in eastern Australia. The recent high temperatures experienced are likely due to the current influence of El Niño combined with the background, long-term warming that has been observed across Australia since the start of last century.

A special climate statement was released during the month giving further details about the heatwave conditions that were experienced through central and south-eastern Australia.

Some sites had their highest November temperature on record.

Some sites had their highest November mean daily maximum temperature on record.

See a map of maximum temperature anomalies.

Some sites had their highest November mean daily minimum temperature on record.

See a map of minimum temperature anomalies.

Wind

Canberra winds were predominantly NW, accounting for 37% of the observations (compared to the usual 33% from this direction), which is consistent to that expected with warm conditions. The highest wind gust in the region was 87 km/hr at Mt Ginini on the 16th. Canberra Airport recorded its highest wind gust of 80 km/hr on the 3rd of the month. In both instances, the gusts were related to the passage of low pressure systems.

Other phenomena

Canberra Airport reported thunderstorms on five days during the month (on the 1st, 2nd, 20th, 26th and 27th), which is close to the historical average of four days.

Relative humidity was lower than usual, with an average of 56% at 9am (historical average 63%) and 32% at 3pm (historical average 41%). These figures are also consistent with the warmer conditions from the predominantly northwest airstream. Canberra Airport recorded a mean of 8.9 hours of bright sunshine per day, which is equal to the historical average. There were 12 days where there were 12 or more hours of bright sunshine, however, a cloud band which passed through the region during the period 21st to 24th (a total of 8.3 hours over the four days) resulted in the mean number of hours reducing back to average.

Further information

Media
(03) 9669 4057
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Extremes in November 2009
Hottest day 38.9 °C at Canberra Airport on the 20th
Warmest days on average 29.0 °C at Canberra Airport
Coolest days on average 27.3 °C at Tidbinbilla *
29.0 °C at Canberra Airport
Coldest day 6.8 °C at Mount Ginini AWS on the 29th*
18.3 °C at Canberra Airport on the 5th and Tuggeranong AWS on the 23rd
Coldest night 7.3 °C at Canberra Airport on the 14th
0.0 °C at Tidbinbilla on the 30th*
Coolest nights on average 11.6 °C at Tidbinbilla *
12.5 °C at Tuggeranong AWS
Warmest nights on average 12.7 °C at Canberra Airport
Warmest night 19.1 °C at Tuggeranong AWS on the 21st
Wettest overall

27.1 mm at Nicholls (Gungahlin Lakes)
62.0 mm at Mount Ginini AWS*

Driest overall 8.4 mm at Torrens (Darke St)
Wettest day 11.6 mm at Canberra Airport on the 27th
30.4 mm at Corin Dam on the 1st
Highest wind gust 87 km/h at Mount Ginini AWS* on the 16th
80 km/h at Canberra Airport on the 3rd

* Incomplete data record.


Record highest November temperature
Highest temperature
in November 2009 (°C)
Previous highest
for November
Years of
record
Average for
November
Canberra Airport 38.9 on the 20th = 38.9 on the 26th in 1997 71 22.7



Record highest November mean daily maximum temperature
Mean daily maximum
temperature
for November 2009 (°C)
Previous highest
for November
Years of
record
Average for
November
Canberra Airport 29.0 28.7 in 1982 70 22.7
Tidbinbilla * 27.3 27.2 in 1982 23 21.8
* Incomplete data record.


Record highest November mean daily minimum temperature
Mean daily minimum
temperature
for November 2009 (°C)
Previous highest
for November
Years of
record
Average for
November
Canberra Airport 12.7 11.8 in 2007 70 8.7
Tidbinbilla * 11.6 = 11.6 in 2007 23 8.7
* Incomplete data record.


Summary statistics for November 2009
Maximum temperatures
for November
(°C)
Minimum temperatures
for November
(°C)
Rainfall
for November
(millimetres)
Mean for
November
2009
Diff
from
average
Highest for
November
2009
Mean for
November
2009
Diff
from
average
Lowest for
November
2009
Total for
November
2009
Average
for
November
Rank of
November
2009
Fraction of
November
average
Southern Tablelands (Goulburn-Monaro) (district 70)
Canberra Airport 29.0 +6.3 38.9 20th 12.7 +4.0 7.3 14th 17.0 63.9 v low 27%
Tidbinbilla * 27.3 +5.5 36.5 20th 11.6 +2.9 0.0 30th 12.5 84.4 v low 15%
Tuggeranong AWS 28.8   37.9 20th 12.5   7.6 8th 12.8

* Incomplete data record.


Notes

A Monthly Climate Summary is prepared to list the main features of the weather in ACT Monthly Summary 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 Tuesday 1 December 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.
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