MONTHLY CLIMATE SUMMARY - ACT

Record dry six months for ACT after meagre July rainfall

July 2004 was again very dry in the ACT, with above-average daytime temperatures and slightly below-average night-time temperatures.

Rainfall: Only 10.8 millimetres of rain was recorded at Canberra airport in July, well below the average of 41.4 mm, continuing the significant dry spell since January this year. Rain was recorded on 13 days, more than the average of 10, but on many occasions it was minimal rainfall. The January-to-July rainfall total this year is the second lowest on record. The February-to-July and March-to-July totals are the lowest on record. The April-to-July total is also the second lowest on record. Rainfall totals across the ACT varied from 38.4 mm at Corin Dam to 9.0 mm at Queanbeyan. There were six days of fog in July (average seven) with no thunderstorms (average zero) or hail. While no snow was recorded at the airport, there were reports of snow in the ACT and surrounding region on 17 July.

Temperature: The mean daily maximum temperature for the ACT in July was 12.1 degrees Celsius, well above the long-term average of 11.2 degrees. The mean daily minimum temperature of minus 0.4 degrees was just below the long-term average of minus 0.1 degrees. It was the coldest day in Canberra for three years on 17 July when the maximum temperature reached only 6.5 degrees (the temperature reached only 5.5 on 6 July 2001). It was the coldest morning in Canberra for seven years on 21 July when the minimum temperature reached minus 7.3 degrees (the temperature fell to minus 7.4 on 2 August 1997). The 21 July minimum of minus 7.3 degrees was also the coldest July morning for 17 years (the temperature reached minus 8.0 on 13 July 1987). There were 22 frost days in July, just above the average of 21. The mean daily temperature (the average of maximum and minimum temperatures) of 6.0 degrees was higher than the long-term average of 5.7.

Other: July was windier than normal. The average daily wind run at two metres was 212 kilometres a day, much more than the long-term July average of 170 km/day. There were four days of strong winds (average two). The average daily pressure was 1022.6 hectopascals, well above the long-term average of 1020.4 hPa. The mean daily sunshine of 6.0 hours a day was more than the average of 5.7 hr/day. The monthly evaporation of 56.2 mm was also above the long-term average of 51.7 mm.

Summary for Canberra airport, July 2004

Mean maximum temperature: 12.1°C (av 11.2°C)
Highest maximum temperature: 16.5°C (10 July)
Lowest maximum temperature: 6.5°C (17 July)
Mean minimum temperature: minus 0.4°C (av minus 0.1°C)
Highest minimum temperature: 7.2°C (25 July)
Lowest minimum temperature: minus 7.3°C (21 July)
Lowest grass temperature: minus 12.0°C (21 July)
Total monthly rainfall: 10.8 mm (av 41.4 mm)
Total monthly evaporation: 56.2 mm (av 51.7 mm)
Mean daily sunshine: 6.0 hrs/day (av 5.7 hrs/day)
Mean daily pressure.: 1022.6 hPa (av 1020.4 hPa)
Mean daily wind run (at 2 metres): 212 km/day (av 170 km/day)

Ends

Further information:
Clem Davis, Canberra Meteorological Office, tel: (02) 6249 6269, e-mail: c.davis@bom.gov.au