Wet Autumn 2017

Sunset photo.

Manilla Sunset

Autumn this year had normal temperatures, in stark contrast to very high temperatures both in the summer and in the autumn of last year. The decline to winter was not smooth, however, but went by steps. For three weeks in each month there was no cooling then, after some rain, there was a sudden cooling through three, four, or five degrees.
Rain fell frequently except for two gaps of a fortnight each, the first coming in mid-April. The second ended with 32.8 mm of rain registered on May the 20th. There were 26 rain days, which is twice usual number, and more than in any autumn in the new century.

Graphical log for autumn 2017

There was plenty of moisture. Only the early morning dew point (8.1°) was low, by half a degree. The daily temperature range was a narrow 14.5°, and the cloudiness a high 41%.
The total rainfall of 192.8 mm was at the 80th percentile, far above the autumn average of 134 mm. There has not been a wetter autumn since 1990 (203 mm). A little earlier there was a cluster of wetter autumns: 1977 (307 mm), 1979 (203 mm), 1982 (238 mm), 1983 (314 mm: 4th wettest), and 1988 (231 mm). Autumn 1894 was the very wettest, with 388 mm.

Climate for autumn 2017


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

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Autumn 2016 had many warm spells

Photo of a garden in Manilla NSW

Autumn Garden

The season was marked by a series of warm spells. The three warmest, coming early in each month, reached 3° to 4° above normal. In the first two, days and nights were equally warm; in the third, nights were much higher above normal than days, making the daily temperature range narrower than normal by 4°. The only cool spells having temperatures below normal were in the third week of March and the last week of May. All three frosts of this season came in the final week .
Rain came in five episodes, spaced a week or two apart. There were 12 rain days, which is the usual number, but the highest reading was only 20.8 mm.

Weather log for autumn 2016
This was the warmest autumn in this short record. Daily maximum, mean, and minimum temperatures were all more than 1.5° above the average for the decade beginning March 1999. The subsoil temperature at 750 mm was also rather high.
The composite Moisture Index was normal, rainfall being a little low and cloudiness rather high (36%, when the autumn “normal” is 25%).
The total rainfall of 88.3 mm was below the autumn average of 134 mm, and in the 35th percentile.

Climate for autumn 2016.


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.

Cloudy autumn in 2015

Photo of eucalyptus tree

Eucalyptus albens in bloom

For a time around the 20th of April, days averaged five degrees colder than normal. At that time nights were warm, making the daily temperature range a remarkable eight degrees less than normal. On three occasions the dew point (humidity) was down by six degrees or more: early and late in March, and in mid-May. The sub-soil temperature was low most of the time by up to half a degree, but ended one degree high. Rain fell in each fortnight. The number of rain days (19) was high, but the highest daily reading (26 mm) was normal. Weather log for autumn 2015 This autumn, like the last, was moist. The rainfall, at 137.5 mm, was a little higher (on the 60th percentile) and the mean daily temperature range was a new record narrow value of only 14.0°. The season was very cloudy, with 41% cloudy mornings, but did not beat last year’s record 48%. The early morning dew point, 7.2°, was not even up to normal (8.5°). Warm nights and cool days made the mean temperature normal. Climate for autumn 2015


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

Autumn 2014 cloudy with warm nights

Austral bluebells in autumn

Autumn bluebells

There were two severe cold spells in late March and early May. Days were several degrees colder than normal, and the daily temperature range was narrow. To compensate, there were three spells of very warm nights in early April, late April, and late May. The last of these also had warm days and lasted a fortnight.

Weather log autumn 2014

Rain fell on 23 days (twice the normal number), totalling 132.8 mm. Most of it (84.8 mm)  fell in the week beginning on the 24th of March. The autumn total is on the 125-year average, and in the 58th percentile.

In autumn seasons from 1999, this was equal warmest with 2007, but nights (11.8°) were by far the warmest, 1.3° above normal. The mean daily temperature range, at 14.1°, was the narrowest, and the percentage of cloudy days (48%) the highest. All these point to a more moist (maritime) climate than does the rainfall or the dew point.

Climate for autumn 2014


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

Autumn 2013 began wet

Weather log Autumn 2013Three quarters of the rain this autumn fell in the first two days: 31 mm and 45.4 mm. After that, the heaviest falls were 6.2 and 6.8 mm late in May. Days were cool with the rain, and warm in late March and late April. The warm days in late March came with warm nights, but the warm days in late April brought very wide daily temperature ranges instead.

This autumn was like autumn last year. That is, it was near average in most respects, but with high subsoil temperature and plenty of cloud. Dew points were even lower, reaching a record low value of 6.1°.
Rain fell on 11 days (normal), totalling 103 mm. This is below the 125-year autumn average of 133 mm, and in the 46th percentile.Climate autumn 2013

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.

In 2012, Autumn Weather Normal Again

Weather log autumn 2012.
After the cold, wet summer, autumn weather was normal, like last year. Days were warm in early April, and nights cold in mid-May. Rain was rather light: the four days with more than 10 mm of rain came in late April.
Average air temperatures were close to normal, but the early morning Dew Point was 2.1 degrees down, showing very dry air, as in autumn 2008. The subsoil was very warm.
While the percentage of mornings with more than 4/8 cloud (39%) was lower than in the last two autumns, it is still nearly twice that of autumns in the previous decade, which averaged just 25%.
Rain fell on 16 days (normally 12), but the total rainfall of 87.4 mm is only on the 35th percentile for autumn. Like autumns in 2009 and 2010, it is about 45 mm below the average (133 mm). Nevertheless, an enormous amount of rain fell in spring, summer, and autumn taken together: 852 mm! Only 1956 and 1890 had more rain in those three seasons: 1012 mm and 939 mm.Climate autumn 2012

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.

Autumn 2011 Normal but Cloudy

 

Weather log autumn 2011Normal autumn weather was broken by an almost rainless period from mid-April to late May. Temperatures fell very low, particularly at night. The minimum of minus 2.8 degrees on 15/5/11 was a record for autumn. The coldest nights were exceptionally dry: 17/5/11 had the lowest Dew Point in thirteen years, -9.3°. Even during the extreme drought of July 2002, with four Dew Point readings below -6°, the air did not get nearly so dry.

On the average (as shown below) temperatures and the Dew Point were near normal, except that days were rather cool, as in autumn 2008. On average, that autumn, however, was much drier, with cold nights. Autumn 2007 had been very warm and wet.
This time, the percentage of mornings with more than 4/8 cloud was 43%. That almost matches last autumn’s 45% and is far above those of autumns in the previous decade, which averaged just 25%.
Rain fell on 21 days, an unusually large number. The total rainfall of 116.8 mm is on the 52nd percentile for autumn. It is 16 mm below the autumn average (133 mm).Climate autumn 2011

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.