Warm Nights in Summer 2009-10


Weather log summer 2009-10

No warm spell this summer matched that of late November, which had four days over 40°. There was only one 40° day all summer. By February there were no warm spells.
Summer began hot and very dry, with clear skies and low humidity. Year’s end saw days of rain, low cloud and extremely high humidity. In mid-January the air was again very dry, but cool.

The mean daily maximum temperature was normal, but the mean minimum (18.7°) was the highest in eleven summers. The number of nights warmer than 20° (34) is also the highest, nearly twice the usual number.
The total rainfall of 190 mm is below the long-term summer average of 225 mm. It is in the 42nd percentile.
At 42% cloudy mornings, this summer was very cloudy, but not extremely cloudy like the summer of 2007-08 (53%). These summers shared the record for completely overcast mornings, with 18 each.

Climate for summer 2009-10


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.

Parched December 2009 went soggy

The daily weather log

Weather log December 2009

December began dry, very warm, and almost cloudless. In all, there were fourteen days over 35°: remarkable except that it had happened in November too! Plants began dying from lack of rain and low humidity. By the 19th there had been 39 days without 5 mm of rain. The Dew Point on the 12th (-1.1°) was the lowest for a December morning.
Within a week, the sky became overcast, the days cool, and the humidity extreme: the Dew Point from the 27th on was near or above 20°. The hills were often hidden in cloud or rain. The highest rainfall reading (44.6 mm) is a total of several rain days. Heavy rain fell during Sunday the 27th.

 Comparing December months

Climate December 2009

The mean maximum temperature (33.1°) is not as high as in December 2005 (33.7°), but the mean mean (25.9°) and mean minimum (18.6°) are the highest for the decade. All are two degrees warmer than normal, but not extreme as in November.
At 52% cloudy mornings this month was very cloudy, but not as cloudy as December 2007 (58%). The mean morning Dew Point, 12.6°, was normal.
The rainfall total of 75.6 mm is in the 55th percentile, just above the median for December. Most totals for more than one month are quite good. Shortages affect the 6-, 9-, and 12-month totals, but even the 9-month total (now 334 mm) is no longer a serious shortage: it is in the 13th percentile. A shortage in the 10-year rainfall total (15th percentile) may be keeping river base-flows and deep water tables down.

The year 2009

The year 2009 was dry, with only 495 mm of rain. That is on the 16th percentile, meaning one year in six has been drier. It followed two wet years, 2007 with 741 mm (68th percentile) and 2008 with 720 mm (64th percentile).

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


November 2009 – Extreme Heat

The daily weather log

Weather log November 2009

November 2009 broke records for heat at any time of year in the last decade:
Highest daily maximum temperature: 42.6° on 20/11/09;
Highest daily minimum temperature: 27.8° on 22/11/09;
Highest weekly average: 31.3° for 17-23/11/09.
The daily maximum on the 20th was a record 13.5° above normal, and the daily minimum on the 22nd was one of only three nights over 13 degrees above normal.

 Comparing November months

Climate November 2009

Mean monthly temperatures were the highest on record for November: mean daily maximum 34.3° (5.2° above normal); mean daily mean 26.0° (4.6° above normal) mean daily minimum 17.8° (4.0° above normal). The early morning Dew Point (10.9°) was normal, but hot air brought the Relative Humidity down.
Rainfall of 33.4 mm recorded on the 9th was welcome, but little fell later. In all, five rain days totalled 40.0 mm. This total is low: in the 28th percentile for November. Most totals for more than one month are fairly good but a severe shortage (3rd percentile) affects the 9-month total (266 mm).

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


October 2009 began cool and dry

The daily weather log

Weather log October 2009

The first two weeks of October were cool – as cool as September, and no warmer than late August. There was little rain, low humidity and strong winds. The sub-soil temperature (at 750 mm) also remained low, not reaching 18° until the 18th, two weeks later than usual. Some cotton plantings suffered.
A warm spell came on the 20th, with the maximum on the 23rd (35.4°) being 8° above normal. By contrast, a rainy day on the 26th reached only 18.1°, more than 9° below normal. That day was the first in 33 days to have more than 5 mm of rain. Ten rain days (usually 7) brought 47.4 mm for the month.
Seven days began with a brown dust haze, adding to one in July, three in August, and seven in September.

 Comparing October months

Climate October 2009

Mean temperatures were close to normal. The mean humidity (early morning Dew Point: 4.3°) was low: lower than in 2007, but higher than in 2002 (3.3°). The percentage of cloudy mornings was normal.
The rainfall total, 47 mm, is in the 39th percentile for October, just 6 mm below the median (53 mm). Despite early worries, most rainfall totals improved. The only serious shortage affects the 6-month total. At 164 mm, it is in the 7th percentile.
Totals for periods longer than nine months are normal: the lowest is the ten-year total, which is in the 21st percentile. From November 1999 Manilla has had 6133 mm of rain, against the median 6393 mm. That is a shortfall of only 26 mm per year.

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


September 2009 warm and dusty

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.