December 2019: very hot and dry

Sun in smoke

Red Sun 17 Dec

After the first week, each week in December was very hot, reading up to 5.9° above normal. Both days and nights were hot, but only one record was set: 42.2° on the 21st was the hottest December day. That was well below the record hot day of 44.9° set on 11/2/17.
Twenty mornings were cloudless which was twice the usual number. Smoke from mainly coastal bushfires reduced visibility to 15 km or less from the 8th to the 25th. Early in the month, rain fell on three days, the highest reading being 12.4 mm on the first day.

December 2019 weather

Comparing December months

This month broke 21st century records for December mean monthly temperatures. The mean minimum of 18.7° just beat 18.6° of December 2009, the mean average of 27.6° easily beat 26.1° last year, while the mean maximum of 36.5° was far above last year’s 33.9°.
On balance, indicators of moisture make this the driest December of the century. Rainfall, at 19.6 mm, was lower than any but December 2006 (18.8 mm), and the dew point was equal lowest with 2013. This month had by far the fewest cloudy mornings (10%) and the widest daily temperature range (17.8°).

December 2019 climate

Drought

I will report separately on the on-going drought that continues to break low-rainfall records at durations of 15-months and longer.


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. Recording resumed on 20 July 2019.
My estimates of early morning dew point have drifted anomalously low. From August 2019, I use data from the Tamworth Airport published graphs.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

Spring 2019 hot and very dry

Blooming senna bush

Senna coronilloides

Spring was marked by a succession of warm and cool spells. Nights varied around the normal seasonal temperature but days had no spells cooler than normal. A hot spell late in November had days 6° above normal as a weekly average. The dew point showed very dry air in mid-November.
There were nine rain days, as in the droughty spring of 2002. The highest reading was 16.6 mm. Rainy and cloudy days came about every three weeks.

Weather log spring 2019

The hot dry climate this spring was very like that of 2014, and quite unlike the cool wet climate of 2016.
Days, averaging 29.0°, were hotter than in any spring except 2002 (29.2°). Nights, at 11.2°, were only half a degree above average. (The winter of 2019 had a similar pattern.)
Dryness was shown by very little morning cloud (21%), very low early-morning dew point (3.7°) and very wide daily temperature range (17.8°).
The total rainfall of 62.4 mm makes this the fourth driest spring, after 1957 (23 mm), 1944 (40 mm), and 1951 (54 mm).

Climate spring 2019


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. I have used it since 20 July, when the Museum gauge began recording again. My estimates of early morning dew point have become anomalously low. From 1 August 2019, I use values taken from Tamworth Airport graphs at the time of minimum temperature.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

November 2019: one warm week

Bushfire smoke

Manilla View 18-11-2019

One week, beginning on the 20th, was 5.4° warmer than normal. The night of the 22nd did not get cooler than 24.0°, making it the 5th warmest November night in this century. (One night in November 2009 had been 27.8°, the warmest night of any month.) In other weeks of this month, temperatures were normal.
Most days were dry and sunny. However, days early and late in the month were cloudy, with high dew points and narrow daily temperature ranges. Six of these days had rain, with the highest reading 16.4 mm on the 4th.
Smoke from coastal bushfires reduced visibility from the 17th to the 29th. On the 18th, visibility was only one kilometre, as shown in the photo.

November 2019 weather log

Comparing November months

Although this month was warm. other November months have been warmer: in 2002, 2009, 2012, and 2014. All of these had especially warm days. While days this month averaged 31.8°, days in November 2009 averaged 34.3°. The coolest recent November was in 2017.
This was a dry month but, by various measures, not as dry as in 2002, 2009, 2014 or 2016. The rainfall total of 40.2 mm is in the 27th percentile.

November climate

Drought

I will report separately on the on-going drought that continues to break low-rainfall records at durations of 15-months and longer.


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. Recording resumed on 20 July 2019.
My estimates of early morning dew point have drifted anomalously low. From August 2019, I use data from the Tamworth Airport published graphs.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

Warm, dry October 2019

White box tree

My old E. albens.

The first week was 5 deg warmer than average, and the fourth and fifth weeks were also warm. The 7th of the month, at 37°, was the second hottest October day in this century, then the night of the 25th, at 21.3°, was the warmest October night.
Most days were sunny. Rain was recorded on the 12th (16.6 mm) and the 17th (4.4 mm).

October 2019 weather log

Comparing October months

This was the second-warmest October of the new century by all three temperature measures: daily max: 29.7°; daily mean: 21.2°; and daily min: 12.7°. The warmest had been October 2015, with 30.2°, 21.7°, and 13.1°.
It was a dry month but, by various measures, not as dry as in 2013 or 2014.
The rainfall total of 21.0 mm is in the 16th percentile, and the 20th driest on record.

October climate

Drought

I will report separately on the on-going drought that continues to break low-rainfall records at durations of 15-months and longer.


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. Recording resumed on 20 July 2019.
My estimates of early morning dew point have drifted anomalously low. From August 2019, I use data from the Tamworth Airport published graphs.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

Dry September 2019

Striped Honeyeater at the Window

Weekly average temperatures increased slightly, as is usual in September. Unusual day temperatures came early in the month. The first 30-degree day was 18 days early, on the 5th. The next day was the hottest of the month, at 31.9°. During the next 3 days the daily maximum temperature fell by 16.9° to 15.0°, the coldest day of the month. Later, temperatures stayed closer to normal. There were 4 frosts, the usual number.
At the Manilla Museum, 1.2 mm of rain was recorded on the 23rd.

Comparing September months

The last three September months have all been dry, with low dew points, wide daily temperature ranges and not much cloud. They have not been nearly as hot as September of 2013, however.
The rainfall total of 1.2 mm is the 3rd lowest September reading, after 0 mm in 1980 and 1 mm in 1925. By way of contrast, the second graph also includes the deluge of 122.4 mm in September 2016, the 4th wettest on record.

Drought

I will report separately on the on-going drought that continues to break low-rainfall records at durations of 15-months and longer.


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. Recording resumed on 20 July 2019.
My estimates of early morning dew point have drifted anomalously low. From August 2019, I use data from the Tamworth Airport published graphs.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.