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.
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.
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.
There were fourteen rainy days in a month that ended no warmer than it began. The month of September normally warms up by nearly four degrees. This time it remained near 14° all month. Some plants encouraged by the plentiful moisture were discouraged by the cold.
The highest daily rainfall reading, 28.8 mm on the 14th, hardly compares with one of 71.1 mm in 2005, or even one of 40.0 mm in 2011.
No days were warm. For the first time in this 18-year record, no September day reached 25°. More days than ever (18) were below 20° but not one was as low as 15°. Temperatures at night were near normal. A frost on the 5th was the only one. It may have been the last of the year, about a fortnight earlier than usual.
Only four mornings this month had no cloud, while seven were totally overcast.
Comparing September months
For monthly average temperatures, the daily maximum of 19.7° stands out as a record low, 4.1° below normal. Three indicators for moisture reached their extreme September values for the new century: rainfall, percentage of cloudy mornings (63%), and (narrowest) daily temperature range (12.0°). Dew point (6.0°) was just above normal, but very much higher than in September months since 2010.
The monthly rainfall total of 122.4 mm (amended) was one of the four highest ever September readings. The others were: 1917: 124 mm; 1949: 126 mm; 1998: 166 mm.
There are not now any noteworthy shortages in rainfall totals for any number of months, up to 360 months (thirty years).
Data. Rainfall figures for this month are from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.
As in December and January, nearly all the days and nights of February were cooler than normal. No days went over 35°, and no nights over 20°. Wednesday the 1st reached only 18.5°, which is 15.3°below normal! Rain that began three days earlier, totalled 145.2 mm by the 4th : one-fifth of a year’s rain in seven days! However, there was no flooding.
In all, February had 11 rain days, totalling 196.3 mm, with 73.2 mm on the 2nd.
Comparing February months
While this month’s mean daily maximum temperature was nearly 3° below normal, February 2008 was cooler on all measures.
The Dew Point was again low: very dry air persists, despite cloudy skies and extreme rainfall.
The rainfall of 193.6 mm is in the 97th percentile for February, the fifth wettest in 129 years. As this combines with the November deluge, rain totals for groups of 4, 5, and 6 months have near-record values: 4 months: 576 mm (3rd wettest); 5 months: 674 mm (4th wettest); 6 months: 765 mm (3rd wettest). Total rainfalls for longer periods, up to 30 years, are now all well above average.
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.
There were about six cycles of low and high temperature during spring. The third week of October was particularly cool, with dry air. By contrast, days and nights were more than seven degrees warmer by the end of the month.
There were 27 rain days, eight more than usual. Although the total rainfall (295 mm) was extremely high, the highest daily fall was only 52 mm. There were only two mild frosts early in the season.
The mean temperature was normal for spring. Rather cool days and rather warm nights combined to make the daily temperature range (14.4°) the narrowest for the decade, well below the average of 15.9°.(Note added. The mean daily temperature range for spring 2010 was far narrower: 12.9°.)
This spring was rather more humid, and had rather more cloud than usual.
This was the seventh wettest spring in the 126-year record, equal with 1973. Wetter springs occurred only in two clusters. The first cluster was 1916 (326 mm) and 1917 (327 mm); the second was 1949 (330 mm), 1950 (379 mm), 1954 (319 mm) and 1955 (321 mm). (Note added. Spring 2011 was very much wetter, with a record spring rainfall of 431.7 mm.)
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.
This November was like last November, but wetter. Again, a sunny dry week separated times of overcast rainy days.
Sudden cold changes, which had come twice in October, came again on the 8th, 17th, and 22nd. The last was severe. The maximum on the 23rd was nearly 12° below normal. The temperature that day did not rise above 15° until 5 pm!
Steady soaking rain on the 3rd amounted to 44 mm. A long spell of six rain days from the 17th brought another 48 mm. It began as persistent drizzle but included storms (one with 15 mm size hailstones). These days had low cloud and high humidity. Extremely low humidity (Dew Point 0.1°) came with the cold change, but dew points rose to a peak of 17.4° on the 29th. Over 26 mm of rain fell that day.
Manilla missed two heavy rainstorms of 80 mm each that swept through Tamworth at 10 am and 10 pm on the 28th. There was flooding at Tamworth, at Carroll Gap, and on the plain east of Gunnedah. The Namoi River at Manilla also rose due to rain near Bendemeer.
Comparing November months
Days were the coolest in ten Novembers. However, the mean daily minimum was high, making the daily temperature range (12.4°) even narrower than last November. This agrees with high values for cloudiness and dew point.
The rainfall total, 132 mm, is far above the long-term November average of 67 mm, but that is now common. Five of the last ten Novembers had 110 mm or more. This month and November 2000 were equal ninth wettest on record, and November 2001 (133 mm) eighth wettest.
The rainfall totals for groups of months get higher and higher. The total for 2 months (October and November) is in the 94th percentile, 3 months in the 92nd, 4 months in the 86th, 5 months in the 80th, and 6 months in the 81st percentile. Totals are now above the median for periods up to 72 months with only one exception: that for 9 months is in the 47th percentile. The six-year total rainfall is now 100 mm more than in six average years.
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.