Here’s one for those of you that ask us “how’s the weather?” down here. Senior Met Observer Alison Skinn, has looked at our current stats compared with previous years', to see how things are changing here on the ‘green sponge'.
For the sixth month in a row Macca has smashed its average monthly rainfall, with 124.2mm compared to the long term July average of 73.4mm. January received close to average rainfall but since then each month has been considerably above average. The cumulative rainfall for the first seven months of 2016 is 779.0mm from 200 rain days (days with more than 0.2mm). Note that July 31st is the 213th day of the year, so there have only been 13 days without measurable precipitation so far in 2016. Macca's average annual rainfall is 981.6 mm and the wettest year on record was 2015 with 1272.6 mm. We will beat them yet!
Macca’s driest year on record was 1960 with only 721.1mm, a total which is close to Perth’s average annual rainfall and is still significantly wetter than the average annual rainfalls of four of Australia’s other capital cities.
During July 2016 we received precipitation of some sort (rain, snow or hail) on every day of the month. Since 1948, and the start of continuous weather data collection at Macquarie Island, we have only once had a month where the number of rain days has been less than half the month. March 1984 had only 14 days with precipitation! The average number of rain days per month on Macca varies across the year between 24 and 28 days a month.
The average maximum temperature for July 2016 was slightly above average, 5.4°C compared to the long term July mean of 4.9°C. Our highest maximum and minimum temperatures for the month came close to equaling July records (close, but no cigar). The highest maximum temperature was 7.8°C on the 12th getting up there with the best on record of 8.3°C from July 14th 2010. The 12th was a rainy and foggy day with northerly winds which is was why the temperature was so high. The warmest minimum temperature this month of 6.4°C on the 13th was just below a July record too, 6.6°C from July 30th 1980.
We didn’t get close to any of the coldest temperature records.
The coldest temperature for the month was −2.7°C, reported in the 9 am observations on the 25th it was actually recorded during the middle of the day on Sunday the 24th.
It was another above average windy month with the mean daily wind run of 998.1km well above the more usual ball park of 740km per day. A definition of wind run – imagine the wind is spinning your car’s tyres for 24 hours, the wind run is the number of kilometres racked up on the odometer. The strongest wind gust was 60 knots from the west at 14:48 on July 20th. We had 27 days out of the 31 with strong winds (above 22 knots). There were 17 days with gales (above 34 knots), well above the July average of seven days. We also enjoyed 15 days with snow fall, seven days with hail, three with fog and 15 with mist. There were 10 days of frost, minimum ground surface temperature −0.9°C or less, so July offered some good firm walking opportunities across the swamp and bog.