At Manilla, NSW, in the twenty years from 2000, the year 2019 was the hottest and the driest, overtaking the year 2018.
Climate records kept at 3 Monash Street, Manilla from April 1999 yield these eight graphs of climate variables. The graphs on the left (red) show heat and those on the right (blue) show moisture.
These graphs show the figures for calendar years, not for seasons.
In general, the temperatures in this 20-year record rose, with a pause between 2004 and 2012. Moisture peaked about 2010.
At Manilla, a sudden rise in temperature and fall in rainfall happened after 2017, having been much slower before that.
Dashed horizontal lines mark the normals for the decade from April 1999.
Left column graphs (red)
Yearly Mean Maximum Screen Temperatures
Day temperatures are shown by the mean maximum temperature in the Gill-type thermometer screen. The year 2019, at 27.91°, had the hottest days by far. The year 2018 had 27.13°, and 2002 and 2014 were almost as warm.The coldest days were in 2008 (24.57°) and 2010 (24.60°), followed by 2001 and 2011.
The 4th-order trend line shows a minimum about 2010, followed by a rapid rise.
Yearly Mean Screen Temperatures
This graph shows warmth in general, as in the study of global warming. Daily maximum and daily minimum temperatures are averaged. The year 2019 was the warmest (19.83°), followed by 2018, 2014, and 2009. The coolest year in this century was 2008 (17.19°), followed by 2001, 2011, and 2012.
The 4th-order trend line shows near-constant temperature from 2000 to 2011, followed by a rapid rise.
Yearly Minimum Screen Temperatures
Night temperatures are shown by the mean minimum temperature in the thermometer screen. While 2018 had not had very warm nights, 2019, at 11.75°, had warmest nights as well as days. The next warmest were in 2014, 2010 and 2009. Years with nights cooler than 10° on average were 2012, 2008, 2006 and 2001.
The 4th-order trend line shows a rise from 2000 to 2008, then near-constant temperature to 2014, followed by a rapid rise.
Yearly Subsoil Temperatures
Yearly temperatures in the subsoil (at 750 mm depth) hardly related at all to air temperatures read in the Gill Screen. The best match is in 2008, when the subsoil temperature was lowest (19.00°), as were the screen mean (17.19°) and the screen maximum (24.57°).
[Note that world temperature was low late in 2007.]
The highest subsoil temperature (22.19°) came in 2013, when the air was not very warm. In 2019, the year with the warmest air, the subsoil temperature was fourth warmest. This record shows the “normal” subsoil temperature of 20.2° to be 2.3° higher than the mean air temperature of 17.9°.
The 4th-order trend line shows an increase of 0.5° from 2000 to 2009, then no further increase to date.
Right Column Graphs (blue)
Yearly Total Rainfall
In the years 2000 to 2017, the average rainfall was close to the long-term mean of 652 mm. The wettest year included was 2011 which, with 839 mm, was not very wet. However, the two final years were extremely dry. The year 2018, with only 327 mm (estimated), was the second driest on record after 1946 (321 mm), then 2019 was the new driest, at 265 mm.
The 4th-order trend line shows a slow increase to 2011, followed by an accelerating decline to date.
Yearly Cloudy Mornings (%)
This measure of cloudiness is based on morning observations of the amount of cloud in octas (“eighths”). It is the percent of mornings with more than four octas. The pattern is like that of rainfall, with highest values in 2010 and 2011, but the years from 2001 to 2006 had very little cloud: less cloud than 2019, which had record low rainfall.
The 4th-order trend line shows a broad peak at 2012, following a trough at 2003.
Yearly Mean Daily Temperature Range
The daily temperature range relates closely to other measures of moisture: moisture reduces the range. However, 2002 (a drought) remained the year with the widest mean daily temperature range.
The 4th-order trend line shows a broad symmetrical peak at 2010-11, flanked by troughs at the drought years 2002 and 2019.
Yearly Mean Daily Dawn Dew Point
Early morning dew point is a measure of humidity. Some details of the pattern agree with those of daily temperature range. The 4th-order trend line is anomalous. It fell rather steadily from the first year (2000) to 2017. Different instruments and protocols contributed to this.