May 2016: cooling down

Photo of caterpillars in procession.

White Cedar caterpillars.

Until the last week of May, the warm weather of March and April continued. Three nights (early mornings) were more than eight degrees warmer than normal. At 16.5°, the early morning of the 1st was the second warmest for May in this century after 16.9° on 3/5/2000. The first frost (a black frost) came on the 25th, not as late as in 2014, when the first frost came on the 8th of June! (More frost information is here.)

I recorded rain on 7 days (normally 3 in May) but 4 of them had less than 2 mm. The highest reading was 13.8 mm on the 2nd. The afternoon humidity was very high (seldom below 40%) which may explain the bothersome mosquitoes.

 Weather log for May 2016

Comparing May months

The month was warm, especially at night, but not as warm as May in 2007 or 1999.
Skies were more cloudy than usual, at 45% cloudy mornings (more than 4/8 cloud). May is usually sunny, with only 24%, but both 2014 and 2015 had a record 52%
The total rainfall of 34.5 mm was near the average of 41 mm, in the 54th percentile. (Since 1998, every May rainfall except 2011 has been below average.) For the seventh month in a row, there are no serious rainfall shortages for totals for any number of months. Again, the greatest shortage is the 48-month total (2211 mm) which is now in the 14th percentile. Ponds persist in Greenhatch Creek, but a neighbour’s dam is dry.

Climate for May 2016


Data. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla. Rainfall data up to 26/3/15 is from Manilla Post Office, Station 055031.

April 2016 also warm

Photo of red flowers

Red flowering gum

In the whole month, only one day and seven nights were cooler than normal. Days and nights warmed together. Weekly average temperature was 4.1° above normal early in the month, and again 3.5° above normal at the very end.
Rain was recorded only on the 10th (5.8 mm) and the 11th (13.0 mm). While the early morning dew point was high only when it rained, the afternoon humidity was always high, falling below 30% only once.

Weather log for April 2016

Comparing April months

Daily maximum, minimum, and mean temperatures were all very high but not record values for April. The mean of 20.5° was beaten by 20.6° in April 2005. In that month, this month’s daily maximum (29.0°) was also beaten (29.5°). This month’s daily minimum (12.1°) was beaten by the record value of 12.2° set in 2014.
The subsoil temperature, and other variables were near normal.
The total rainfall of 18.8 mm was well below the average of 40 mm, in the 32nd percentile. However, for the sixth month in a row, there are no serious rainfall shortages for totals for any number of months. Now, the greatest shortage is the 48-month total of 2191 mm, which is in the 12th percentile. Ponds persist in Greenhatch Creek.

Climate for April 2016


Data. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla. Rainfall data up to 26/3/15 is from Manilla Post Office, Station 055031.

March 2016 had a warm dry spell

Photo of Pittosporum berries

“Native Apricots”

In the first half of March the average weekly temperature was more than three degrees above normal. Nine days had maxima above 35°, when the month usually has only one. However, no day reached 40°, as happened in March last year (20/03/15).
No rain fell in this time: the period of 43 days between February 4 and March 19 may have been the seventh longest rain-free period in 133 years. (No official record is now kept.)
Normal weather returned in the second half of the month. I recorded 20.8 mm of rain on the 19th, and further rain on the 30th and 31st.

Weather log for March 2016

Comparing March months

Despite the cool change, this was the warmest March of the new century. Daily maxima, minima, and means were all 2° above average. The subsoil temperature was also 1° high, as in March 2012 and 2013, but not as high as in 2007 (2° high).
This was not a dry month. The moisture indicators cloudiness, humidity, and (low) daily temperature range were just slightly on the dry side.
The total rainfall of 35mm was below the average of 53 mm, but in the 46th percentile, not far below the median. Again, there are no serious rainfall shortages for totals for any number of months. In fact, the five-month total of 362 mm is high, in the 81st percentile. Ponds persist in Greenhatch Creek.

Climate graph for March 2016.


Data. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla. Rainfall data up to 26/3/15 is from Manilla Post Office, Station 055031.

Spring 2007 climate much as usual

Weather log spring 2007

The daily weather log

As sometimes happens, temperatures did not rise in September until late in the month. They then rose to several degrees above normal and stayed there until the end of October. Early November was very cool, and mid-November warm. The daily temperature range increased in dry periods and decreased in rainy periods.
There were two late frosts below 2.2° in September.

Only 2.2 mm of rain fell in September. Much more fell later, in short wet spells around October 12th and 26th, and November 7th and 24th. The two best daily falls were 17 mm each. Total spring rainfall was 122 mm, falling on 23 rain days.

Very cloudy or overcast skies became common in November.

Comparing spring seasons

Although each month this spring had unusual temperatures, the three months taken together did not. Daily maximum, minimum and mean temperatures for the spring, as well as the daily temperature range (16.0°), were all normal. In the extreme drought of spring 2002, the values had been two degrees higher, and the daily temperature range 17.1°. The spring of 2001 had the lowest temperatures in this record.

Two frosts this spring compare with three on the average. Spring 2004 had 10 frosts, including one in mid-October, and one on 3rd November!

Spring rainfall in 2007 (122 mm) fell 44 mm short of the long-term average (166 mm), due to September being 39 mm down. October was only 6 mm down, and November 2 mm up. Spring rainfall averaged over the last nine years is above the long-term average, because the droughty spring of 2002 is more than balanced by the very wet springs of 1999, 2000, and 2005. These were in the ninth decile for spring rainfall.

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

Cold days in 2007 winter

Weather log winter 2007

The daily weather log

The temperature trends this winter look like a roller-coaster.
June had daily maximum temperatures about four degrees below normal. Two miserable days had maxima eight degrees below. Meanwhile, minimum temperatures were normal.
Maxima returned to normal in early July but, by that time, nightly minimum temperatures were well above normal. All temperatures then plummeted, losing 8°: by mid-July both maxima and minima were about 5° below normal.
By the end of July and early August maxima and minima had shot up again to well above normal. Next, maxima went up while minima went down, making the daily temperature range very large. This temperature range then collapsed to become very small. The winter ended with temperatures near normal.
The high ground in Manilla had 38 frosts* in June, July, and August. The nine-year average is 45. Seventeen nights went below zero and two nights below -4°.
There was quite a lot of rain, but not much fell in July. The amounts were 65 mm in June, 9 in July, and 81 in August. June was above average, July in the second decile, and August in the ninth decile.
There were ten rain days in June, seven in July, and five in August. One event was remarkable: rain fell continuously for more than 36 hours from the morning of 19th August, to a total of 55 mm.
Skies were overcast (8/8) around the periods of rain. In contrast, there were long sunny spells (0/8 or 1/8) in mid-July and the first half of August.

Comparing winter seasons

The average daily maximum temperature was the coldest in the last nine winters. At 16.6°, it was 1.6° below average.
Although the nights of 2005 were warmer, this winter also had warm nights. At 3.4°, they raised the daily mean temperature up to 10.0°, close to normal.
The daily temperature range in winter in Manilla is usually 15.4°. This winter’s cool days and warm nights made its daily range the lowest in these years. It was only 13.2°, typical of places nearer to the coast, such as Singleton.
The winter that stands out is 2002. With the warmest daily maxima (19.2°) and the coldest daily minima (1.7°) it had the remarkably high daily range of 17.5°. Such a range is found mainly in desert areas – which Manilla was at the time!.

Winter is the driest season in Manilla. The average winter rainfall, 125 mm, is just over half the average summer rainfall (227 mm).
This year’s winter rainfall (155 mm) was above average, and near that of 2005 (157 mm). None of the winters on the graph is far from the average except 2002.
The very dry winter of 2002, at 44 mm, was the ninth driest on the 124-year record. It was the driest since 1982 and 1972 (both 32 mm).
The graph just misses the very wet winter of 1998, nine years ago. Split Rock Dam suddenly filled up for the first time. At 304 mm, that was the second wettest winter on record. Only the winter of 1920 was wetter, with 318 mm.
The graph shows the peracentage of mornings with more than four octas of cloud. The winter average is 31%.
This winter, and winter 2000 were the cloudiest. The insulating blanket of cloud stopped the days from getting warm, and the nights from getting cold.
The winter of 2002 had the fewest cloudy days, another sign of how like a desert it was then.

Climate winter 2007

*Frost: A frost occurs when the temperature on the grass is below zero, causing water to freeze in the leaves. Not many stations measure grass temperature. My rule-of-thumb is to declare a frost if the temperature in the thermometer screen (at 1.5 metres) is below +2.2°.

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.