3-year trends to August 2019

Summer record hot-dry (as smoothed)

3-year climate trends to August 2019

August raw anomaly data (orange)

Temperatures

Daily maximum temperature anomaly (all x-axes): near the maximum for smoothed values.
Daily minimum temperature anomaly (lower left): near normal.
Subsoil temperature anomaly (lower right): very high.

Moistures (moist is at the bottom)

Rainfall anomaly (upper left): very low.
Cloudiness anomaly (upper right): normal.
Dew point anomaly (middle left): low, like the other recent values.
Daily temperature range anomaly (middle right): very high.

 Latest fully smoothed data (red), summer 2018-19

Temperatures

Daily maximum temperature anomaly peaked at a record +1.79° in January.
Daily minimum temperature anomaly held the record vaue of +2.16° through January and February.
Subsoil rose rapidly from normal.

Moistures (moist is at the bottom)

Rainfall smoothed anomaly peaked negative in January at the record value of minus 31.75 mm per month.
Cloudiness was normal.
Dew point was low.
Daily temperature range was normal.


Notes:

January data points are marked by squares.

Smoothing Continue reading

Driest Air in August 2018

Tree with a face painted on it.

Painted Box Tree

Temperatures were not far from normal during the month, except that the weekly mean was 3.2° low about the 20th. There were 20 frosts (normally 15), but the coldest morning fell only to -2.7°.
Some rain fell early in the month. Later, with the cold nights, the air became extremely dry, reaching a new record early morning dew point of -12.1°. Abruptly, the 25th brought overcast and high humidity, then rain and fog. Estimated rain was 9.0 mm on the 26th, 10.2 mm on the 27th, and 0.8 mm on the 28th.

Weather log August 2018.

Comparing August months

The month was rather cool, with a mean (10.7°) that was 0.4° below normal, and cold nights (2.0°), 1.1° below normal. Measures of moisture were only slightly low, except that humidity was extremely low, setting a new record mean early morning dew point of -4.2°.
Moderate falls of rain totalled 28.2 mm (estimated), which is at the 40th percentile for August.
I have reported the shortage of rainfall separately ( “Drought Sixth Month: August 2018”) .

Climate in August months.


Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312.  These reports use that rainfall data when it is available.  The record was again defective in August 2018. Seven daily readings were missing. On one of the missing days (the 27th) my rain gauge showed 10.2 mm, the highest daily reading for the month. I have substituted my non-standard gauge readings for all days of both July and August.

All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to August 2018

Cooler and Moister

3-year trends to August 2018

August raw anomaly data (orange)

For now, a retreat from drought is shown by lower temperature, particularly at night, and more rain. Dew point remains very low.

 Fully smoothed data (red)

The summer season, ending in February 2018, can now be fully smoothed. February has a new 21st century record [in blue] for smoothed daily maximum temperature anomaly of +1.58° [x-axis all graphs]. This is bound to be broken by smoothed values for March, and perhaps for April. The record for negative rainfall anomaly (set in the drought of July 2002) is also likely to be broken in March.

Through the summer, all three temperatures rose, and rainfall fell. Other variables were static.


Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.

3-year trends to August 2017

Arid and sunny

3-year climate trends to August 2017

August raw anomaly data (orange)

In August 2017 all moisture indicators except rainfall showed even greater aridity (high up on the graphs) than in July. Daily minimum temperature anomaly (lower left graph) fell extremely low, but both the daily maximum temperature anomaly (x-axis in all graphs) and that of subsoil (lower right graph) were just slightly above normal.

 Fully smoothed data (red)

Fully-smoothed data points now include summer 2016-17. The daily maximum temperature anomaly peaked in February 2017 at +0.9°, much the same temperature as in the previous two peaks: February 2016 and October 2014. The daily minimum temperature anomaly was just about to peak, but the subsoil temperature anomaly was rising persistently.

Moisture anomaly variables, which had moved strongly towards arid in the spring, peaked in aridity during the summer:

Lowest rainfall, in January, was just 13 mm below normal;
least cloudiness, in February, was still 11% above normal;
lowest dew point, in November, was 1.7° below normal;
widest daily temperature range, in January, was only 0.1° wider than normal.

Although aridity reached peaks, this was not an arid summer. The peak values cited were not far from normal, and the graphs show that more arid times occurred within the previous two years.


Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.

Wet August 2016 had two cold days

Photo of knife-leaf wattle blooms

Knife-leaf Wattle

Six days with at least eight millimetres of rain made for a very wet August.
On the average, the temperature was normal until the fourth week, which was cool. However, there were two remarkably cold days. The 3rd, at 10.6°, was the second coldest August day and the 22nd, at 11.6°, the fifth coldest. Most nights were cool, around 1°, but several were much warmer, generally with the rain. Most days were sunny, and eighteen of the mornings were frosty, about three more than usual.

Weather log for August 2016

Comparing August months

On average, the days were cold: as cold as in August 2001, but not as cold as in 2008 or 2010. The average night-time temperature, however, was normal. The dew point, while not high, was higher than in the previous four August months.
The monthly rainfall total of 80.2 mm was twice the average (40 mm), and in the 89th percentile. No rainfall total for any number of months is now below the 19th percentile. That is the 42-month total of 1949 mm, which is a mere 313 mm lower than the median 42-month value. Both Greenhatch Creek and Rushes Creek have flowed in recent weeks.

Climate for August 2016


Data. Rainfall figures for this month are from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.