Thursday, 1 April 2010 - Monthly Climate Summary for ACT - Product code IDCKGC25R0

ACT in March 2010: March begins and ends with rain

• Wettest March since 1993
• Above average minimum temperatures
• Average maximum temperatures and mild conditions

Details Extremes Records Summaries Important notes the top

Rainfall

Following the very high rainfall in February, above average rainfall was again recorded in Canberra during March 2010, with monthly totals as high as 128mm at Mt Ginini. Canberra Airport recorded 93.2mm, almost double the March average of 50.7mm and the highest total since March 1993 (100.8mm). This is the first March with above average rainfall in Canberra since 2003.

The rain fell over only seven days, approximately average for March. Several small falls occurred during the first week of the month, associated with the passage of surface troughs, with rainfall reaching 22.4mm at Canberra Airport on the 8th. This was followed by a period of settled conditions between the 10th and 28th, associated with stationary high pressure systems over eastern NSW. The month concluded with the passage of a further trough system, with scattered rain on the 29th and 30th followed by totals of 36.6mm on the 31st, the highest daily rainfall in March since 2003. The majority of this occurred in 20 minutes, with 20.6mm recorded between 9:40 and 10:00am on the 30th, with reports of localised flash flooding.

Temperature

March 2010 had close to average temperatures in Canberra, with a mean maximum temperature of 24.6°C, just 0.1°C above the March average of 24.5°C. No days during March exceeded 30°C, well below the average of 3 hot days, with the maximum daily temperature at Canberra Airport just 29.1°C. However, no days occurred with maximum temperatures below 20°C at Canberra Airport, compared to an average of 4.3 such days per year. The coldest day recorded anywhere in Canberra was 10.9 °C at Mount Ginini AWS on the 12th.

Minimum temperatures at Canberra Airport averaged 11.6°C during March, 0.9°C above the historical average of 10.7°C. Four consecutive days had minimum temperatures exceeding 15°C in the early part of the month, with a maximum overnight temperature of 19.2°C on the 7th, associated with the passage of a trough and cloudy conditions. The coldest temperature recorded anywhere in Canberra was 1.6°C at Mt Ginini on the 2nd, with overnight minimums reaching 7.5°C at Canberra Airport on the 11th.

Wind

N-W winds prevailed during March, forming 50% of afternoon wind flow, which is normal for March. Winds were generally light, as expected for Autumn, which tends to have the lowest wind speeds in Canberra. No strong wind days were recorded, with the maximum wind gust at Canberra Airport of 52km/hr on the 21st associated with the passage of a low pressure trough. The highest wind gusts anywhere in Canberra were 74km/hr at Mt Ginini on the 9^th, associated with the passage of a cold front.

Other phenomena

Sunshine averaged 8.0 hours per day at Canberra Airport during March 2010, similar to the historical March average of 8.1. 9am relative humidity averaged 78%, well above the historical average of 70%, with 15 days exceeding 80% at 9am. This is the highest frequency since March 1994, with 18 such days. Average 3pm humidity was 46%, similar to the historical average of 42%. Only one thunderstorm was observed at Canberra Airport on the 7th, compared to the March average of 2 thunderstorms.