Tag Archives: cool

Autumn 2008 was dry and cool

Posted in Manilla NSW, Season Weather by

Weather log autumn 2008

The daily weather log

Temperatures were about normal in mid-March and again during parts of May. Otherwise they were low. The daily temperature range was generally higher than usual, but was less on rainy days.
There were nine mild frosts, which is near the average.
Humidity was very low in early April and early May.
There were 13 rain days, which is normal. They were mainly in late April and mid-May, for a very low total of 37 mm. April the 24th was the wettest day, with 12.8 mm.
Cloud varied a lot from day to day. Clear skies were common in March.

Comparing autumn seasons

This autumn was very cool: mean daily mean temperature and minimum temperature are the lowest in the ten year record. Mean daily maximum temperature was lower in 2003, which is one of three autumns sharing the next coolest mean temperature.
This autumn’s very cool nights (8.2°) caused the largest daily temperature range on the graph (16.9°), similar to the 16.8° of 2005. Both came with very low rainfall,
Autumn humidity seems to have decreased through the decade, with this autumn’s Dew Point of 6.4° the lowest.
This graph includes some very dry autumns. Autumn 2005 was the 7th driest on record, in the 6th percentile for autumn rainfall. This autumn was similar, in the 7th percentile. Autumn 2002 was in the 18th percentile, as that year’s drought had not fully developed. By contrast, autumn 2003 and 2007 were wet, in the 72nd and 75th percentiles.
(Contrary to the forecast, this autumn was dry. It was one of twelve autumns on record that had less than one fifth of the preceding summer’s rainfall. Three of the twelve were 2005, 2006, and 2008. This is amazing: something that usually happens one year in ten happened three years in four! Another three of the twelve were 1971, 1973, and 1976. At that time it was three years in six.)
At 26% cloudy mornings, this autumn was normal.

Climate autumn 2008

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

Summer 2007-08 was very cool,cloudy and wet

Posted in Manilla NSW, Season Weather by

Weather log summer 2007-08

The daily weather log

Most summers recently have had one or two days over 40° and nights over 25°. Not this summer! The hottest day reached only 36.3°, and the warmest night 22.1°. Only 37 days went over 30°: half the usual number. Air conditioners may not have had much use!
The 7-day temperature curves show warm spells in the second week of December, and in the second and fourth weeks of January. Temperatures were then normal. The rest of the time they were well below normal.
Daily minimum temperatures were not so low. This made the daily temperature range small, especially during humid spells.
Humid weather (dew point 16°) came with rain in early December, mid-January, and early February. The air was rather dry (dew point 10°) at New Year and in the very last days of summer.
There were 33 rain days (normally 21). The longest dry spells were eight days from the 22nd of January, and nine days from the 20th of February. February the 6th was the wettest day, with 32 mm, and the summer total was high, at 311 mm.
It was a very cloudy summer. More than half the mornings were cloudy (over 4 octas) and many (18) were completely overcast. Only 13 mornings had a sky clear of cloud.

Comparing summer seasons

Mean daily maximum temperature and mean temperature this summer were the lowest in the nine year record. Mean daily minimum temperature was lower in 1999-2000, which has the next coolest mean temperature. While the cool summer of 1999-2000 had a large daily temperature range (15.6°) related to low rainfall, this summer had a very small daily temperature range (13.2°) related to high rainfall and cloud.
The mean daily maximum this summer (29.7°) is 3.3° below the nine-year average. The fall of over 4° from the very high maxima of the last two summers is dramatic.
Humidity was normal for the time of year.
For rainfall, this short record begins with the 15th driest summer (99-00, 125 mm) and includes the 19th wettest summer (05-06, 319 mm). This summer’s rainfall of 311 mm is 84 mm above the long-term summer average of 227 mm. It is on the 83rd percentile.
At 53% cloudy mornings, this summer season is by far the cloudiest of any season in the nine-year record. No others exceeded 41%.

Climate for summer 2007-08

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

December 2007 cool, humid, cloudy, rainy

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log December 2007

Only four days, early in the month, had daily maximum temperatures warmer than normal. Decembers average five days over 35°, but there were none this month. The 22nd was nine degrees cooler than normal, at 24.2°. Daily minimum temperatures varied around the normal values (16°). The 7-day daily average temperature stayed below normal most of the time.

The graphs include the humidity of the air, using the Dew Point idea. All air contains moisture. If it cools to its Dew Point temperature, it gets so moist that cloud or fog forms, and dew appears. On humid days when the Dew Point is above 17°, most people find the weather unpleasantly sultry or sweaty. They find air with a low Dew Point, such as 5° or 10°, very pleasant and refreshing. The Dew Points shown on this graph are the early morning minimum values. Morning Dew Points this December were often between 15° and 18°: too humid for comfort. They never came below 10°.
Many mornings this month were overcast, and there were never two fine mornings together until the 29th.
There were fourteen rain days, with a total rainfall of 129.4 mm. The wettest day was the 4th, with 25.2 mm. There were only two runs of four days without rain, beginning on the 18th and 28th.

 Comparing December monthsClimate December 2007

The average daily maximum temperature this month, 29.4°, was far below the average for the last nine Decembers (31.7°). Only December 1999 had a slightly lower value (29.2°). The daily mean temperature (23.0°) was below average (24.0°), and the daily minimum temperature (16.6°) was near average (16.4°). As a result, the daily temperature range this month was only 12.8°.

The mean morning Dew Point for December 2007 is 14.2°. This high value, (meaning high humidity) seems to be about 2° above normal, but my record is short.
This was one of the three cloudiest months in nine years. The other two were also in 2007: November (50%) and June (60%).
The rainfall total of 129 mm makes this a very wet month. Only 14 Decembers since 1884 were wetter.
The year 2007 was wet: the total rainfall amounted to 741 mm. This is on the 68th percentile, meaning that higher rainfall has occurred roughly one year in three. The rainfall was 90 mm above the average (651 mm). It was the highest total since the strange wet year of 1998 (919 mm). That year nearly 400 mm more rain than usual fell in the six months that are normally the driest: from April to September.

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.