Tag Archives: September

September 2011: Dry Air with Rain

Posted in Manilla NSW, Monthly weather by

Humidity this month was extremely low. Early morning Dew Point readings averaged 1.7°, which is 3.7° below normal for September (5.4°). Relative humidity at sunrise was about 70% instead of 80%, and in the heat of the day 25% instead of 35%. This is the sixth month in a row with very low humidity, beginning with April, which had Dew Points 1.5° below normal.
In thirteen years only three months have had Dew Points further below normal. They were: July 2002 (down 3.8°), October 2002 (down 3.9°), and May 2006 (down 3.9°).
Plants are stressed by such dry air, and litter will burn easily.

The daily weather logWeather log September 2011.

Most September days were warm and sunny, but heavy rain registered on the 9th (38 mm) and on the 29th (40 mm) brought cold windy overcast weather. The 9th, at 12.9°, was the coldest September day on this record. There had been no days colder than 14°.
While many days had no cloud at all, seven days (marked “H”) had a thick smoke haze from Queensland.

 Comparing September monthsClimate September 2011.

Mean temperature readings were below normal by half a degree or more. The extremely low mean early morning Dew Point (1.7°) contrasts with the very high value last September: 7.3°
Twenty-seven percent cloudy mornings is a normal value, but lower than in the last three Septembers.
The rainfall of 91.4 mm is extremely high, in the 94th percentile for September (Average: 41.1 mm.). Rainfall totals for groups of months are all near normal. The nearest to a “drought” is the 6-month total (221 mm) which is in the 21st percentile; the nearest to a “deluge: is the 12-month total (724 mm) which is in the 68th percentile.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.

Rainy, very cloudy September 2010

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log September 2010 Manilla

 

Like August, September had no extremes. Many days had normal temperatures, especially late in the month, and many others were cool. Nights varied, with two frosts, but most were warm.
Rain fell on 11 days, a September record number for the decade. The highest reading was 22.2 mm on the 10th. A reading of 12.6 mm was due to a brief afternoon shower on the 27th.

Comparing September monthsClimate September 2010 Manilla

 

The mean daily temperature (14.9°) was normal, but days (21.5°) were only 13.3° warmer than nights (8.2°). Usually, September has the highest daily temperature range of the year: 16.9°.
Along with cool days and warm nights, there were more cloudy mornings (57%) than in any September on this record. Very high humidity made the mean early morning Dew Point (7.3°) nearly two degrees higher than normal.
The rainfall of 59.3 mm is in the 76th percentile for September, well above the long-term average of 41 mm. Totals for two, three, and four months are now all above the median. The thirty-year total has now reached the median value, after three years below it.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.

September 2009 warm and dusty

Posted in Manilla NSW, Monthly weather by

The daily weather log

Weather log September 2009

Two large dust storms from South Australia filled the sky on the 23rd and 26th, reducing visibility to about 600 metres. (The dust was reported, with a photo, in the “Manilla Express” for 29/9/09.) There was a brown dust haze also on the 2nd, 13th, 14th, 16th, and 17th, and on three days in August and one in July..
The dust storms put an end to a week of very warm days and nights. The cooler air was dry, with Dew Points below zero.
On the 3rd 14.8 mm of rain fell, after 43 days without 5 mm of rain. Six rain days brought 34.2 mm for the month.

 Comparing September months

Climate September 2009

Mean temperatures were all about half a degree above normal, but not as high as in September 2006. The humidity (early morning Dew Point: 2.7°) was a little low, and the percentage of cloudy mornings (30%) a little high.
The rainfall total, 34 mm, is on the 47th percentile for September, very close to the median (37 mm). As a result, rainfall totals have improved. Serious shortages, below the 10th percentile, now affect only the 3-, 4-, 5-, and 6-month totals. The 5-month total (117 mm), being in the 5th percentile, could be called a severe shortage. Totals for longer periods are normal.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperature and other data are from 3 Monash Street, Manilla.

 

September 2008 had good rain

Posted in Manilla NSW, Monthly weather by

The daily weather log

Weather log September 2008

September was a month of changeable weather. It began with normal temperatures returning after a very cold August. Then there was a spell of fine cold weather, with the seven-day mean falling back to 12°, another much warmer fine spell at 18°, and a third at normal temperature (16°).
Between the fine spells there were seven rain days, including very good falls of 19.8 mm on the 1st and 19.0 mm on the 23rd. The total was 66.2 mm.
Despite all the changes, temperatures were not extreme. Only the wet, overcast day on the 6th, reaching 14.3°, was 8° below normal. The hottest day, the 20th, reached 31.5°. Mild frosts on the 10th and 11th did not fall below zero in the screen.
Having twelve mornings completely free of cloud is normal for September. (In 2003, the number was 23!) A milky haze persisted from the 16th to the 22nd, perhaps caused by cypress-pine pollen.

 Comparing September months

Climate September 2008

 

The mean of the daily mean temperatures was normal. The mean of the daily maxima was down, and that of the daily minima was up. This made the mean daily temperature range (15.0°) equal lowest September value of the decade, well below the average of 16.5°.
The humidity (early morning dew point: 5.6°) and percentage of cloudy mornings (30%) were a little higher than usual.
The rainfall total, 66 mm, is on the 82nd percentile for September. This is far above the average (41 mm), but less than the 100 mm of September 2005. Last September, by contrast, had only 2 mm: the third driest on record.
Totals for several months together now show no serious shortages. The total for 2 months (August and September) is in the 52nd percentile, 3 months in the 41st, 4 months in the 47th, 5 months in the 32nd, and 6 months in the 22nd percentile. Rainfall totals for longer periods are normal.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperature and other data are from 3 Monash Street, Manilla.

 

September 2007 fine and dry

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log September 2007

Very light rain fell on three days in September, for a total of only 2.4 mm. By the end of the month, it had been 40 days since good rain. Such dry Septembers occurred only in 1914 and 1919, and drier ones in 1925 (1 mm) and 1980 (0 mm).

Although this month’s rainfall was in the 3rd percentile of monthly values, rainfall in recent months has not been far below normal. The two-month rainfall ending this month was in the 41st percentile and the nine-month rainfall was actually above the median, in the 53rd percentile. Low rainfalls near the 20th percentile are seen for groups of 3, 5, 6, and 18 months. Other groups of months, (4, 12, 15, 24, 30, 36, 42, and 48 months) are not so bad. They had rainfalls from the 30th to the 45th percentile.
September days and nights were a little cooler than normal. As in some other years, the 7-day mean temperature did not rise until late in the month. The 5th was a very cold day, with daily maximum 7° below normal; the 27th was a very warm night, with daily minimum 7° above normal. Two mornings (7th and 23rd) were as cold as 1.9°, qualifying as “frosts”.
There were only 5 cloudy mornings. All the others were fine, with 1/8 cloud or less.Climate September 2007

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperature and other data are from 3 Monash Street, Manilla.