July 2017 fine with cold nights

July morning photo of Manilla from the lookout

Manilla Prospect in July

Through most of the month, days were fine and sunny, but some days, mainly in the middle, were cloudy and some had a little rain. The highest reading, on the 16th, was only 7.4 mm.
No days were remarkable except the 28th which, at 23.7°, equalled the record for July set 31/07/14. It was 6.1° above normal.
Frosts (below +2.2° in the screen) happened on 23 mornings, 6 more than normal. However, the coldest morning, at -2.6°, was not nearly as cold as the record of -5.1° set in 2002.

Weather log

Comparing July months

Unlike July 2016, which had been cloudy with warm nights, this July was fine with cold nights. Days, at 18.1°, were not quite as warm as in July 2013 (18.9°), the warmest in the new century.
Moisture was scarce, as in the record-making July of 2002. Readings that reflected low moisture were:

Daily minimum temperature very low: +1.2° (2002: 0.9°);
Very many frosts: 23 (2002: 27);
Very low percentage of cloudy mornings: 29% (2002: 23%);
Very low early morning dew point: -1.4° (2002: -1.4°);
Very wide daily temperature range: 16.9° (2002: 18.5°);
Very low rainfall: 13.2 mm (2002: 1.0 mm).

Relative humidity in the early mornings, normally 90% in July, was 74%. That was the lowest July value in my 13-year record.
Despite the total rainfall of 13.2 mm (16th percentile) being far below the July average (41 mm), there are still no shortages of rainfall for groups of months. The most recent serious shortage was nearly two years ago. In October 2015, the 30-month total to that date (1216 mm) was still down at the 6th percentile. That shortage was carried over from an earlier extreme event: the 85 mm summer rainfall of 2013-14 that was 142 mm below average.

Climate graph for July

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.

November 2015 had warm days and nights

Photo of seeding clematis

“Old Man’s Beard”

By the last week of October, the weather had cooled down to normal. In November, this continued until the 15th, with rain falling on eight of the days. The highest rainfall reading was 30.0 mm on the 5th.
After that, the weather was fine. Both days and nights were warm, but no day got to 40°. The weekly average temperature reached about four degrees above normal, as it had done early in October.

Weather log November 2015

 Comparing November months

This was a warm November, by day and by night. However, November 2014 had been hotter, and November 2009 very much hotter. The average daily maximum temperature in November 2009 (34.3°) was nearly 3° higher than in this month (31.5°).
Moisture indicators for this month were close to normal, although there was not much cloud. The dew point is no longer very low, as in the last three Novembers.
The rainfall of 73.8 mm was above average, in the 63rd percentile. The climate graph still includes the phenomenally high rainfall of November 2011: 242.9 mm, the highest November rainfall since the record began in 1883. (The next highest was 226 mm in November 1961.)
There are now no serious shortages in rainfall totals for ANY number of months. For the last 30 years, Manilla has enjoyed rainfalls close to normal. The 30-year total of 19,449 mm to this date is within 100 mm from the median 30-year total of 19,360 mm. In all that time, the most extreme major rainfall events were the 2002 winter-spring drought, and the 2011-2012 summer deluge.

Climate for November 2015

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.

3-year trends to November 2015

Parametric plots of smoothed climate variables at Manilla
“November 2015: warm days and nights”

Trends to November 2015

November raw anomaly data (orange)

While November daily maximum anomalies were not as warm as in October, daily minimum anomalies were warmer (on the lower left graph). Apart from these, nearly all other climatic anomalies for November were near normal.

 Fully smoothed data (red)

The latest fully smoothed data (May 2015) completes the autumn months (MAM) of 2015. In that season, no variables were changing much. Daily maximum temperature, daily minimum temperature, subsoil temperature, and monthly rainfall were all near normal. Skies were rather cloudy, daily temperature range rather narrow and dew point (as is now usual) rather low. It seemed certain that the winter season would see a trend reversal: minimum values in the anomalies of daily maximum temperature and daily temperature range, and maximum values in the anomalies of daily minimum temperature, subsoil temperature, monthly rainfall, cloudiness, and dew point.

The three-year pattern

In these three years, a repeating annual cycle is best seen in the centre-right graph, which relates daily temperature range to daily maximum temperature. In May of each year the climate was relatively cool and equable (or maritime), while in October of each year it was relatively warm and extreme (or continental).


Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.

October 2015 very warm

Photo of native jasmine

Sweetest Jasmine

The first 30-degree day of the season came on the 3rd. That was ten days late, but the first 35-degree day followed soon after, on the 6th. Most days and nights were warm through the month, and the weekly mean temperature was three or four degrees above normal until the last week.
Ten sunny days were followed by days with much more cloud, and four rain days (usually seven). On the 22nd and 23rd, I recorded 17.4 and 8.0 mm.

Weather log for October

 Comparing October months

This was the warmest October of the new century for all daily temperatures: maximum, mean and minimum. The mean temperature of 21.7° was 3° above average, and much higher than in the other warm Octobers of 2014 (20.6°) and 2007 (20.4°).
The graph shows the curious fact that October months have warmed steadily since 2011. Since 2012, Octobers have not become drier: rainfall, cloudiness and humidity have increased rather than decreased.
The rainfall of 35.0 mm was below average, in the 29th percentile. As in last month’s report, there are no serious shortages in rainfall totals for small numbers of months. The only serious shortages are in the 30 month total (6th percentile) and in the 42 month total (7th percentile). There are still deep ponds in Greenhatch Creek.

Climate for October 2015

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.

October 2007 warm, with rain

The daily weather logWeather log October 2007

October was very warm. All but four days had daily maximum temperatures above normal. Night time minima varied at first, and then settled on the warm side. As a result, the seven-day mean temperature was a couple of degrees above normal nearly all the time.

The month began in a dry spell that reached 50-days before good rain fell on the 12th. After that, there was another 12-day dry spell. The dry spells had clear skies, very low humidity, and high daily temperature ranges of around 20°.
By the end of the month, however, a lot of rain had fallen, totalling 52 mm. It fell mainly in four days, with 17 mm on the 26th. The final wet spell was uncomfortably humid.

 Comparing October monthsClimate October 2007

This October was the warmest in nine years. Daily minima were 1.2° above average, daily means were 1.7° above average, and daily maxima were 2.3° above average. The high daily maximum value of 29.4° is usually seen in November, not October.

The rainfall of 52 mm was near the long-term average of 58 mm for October. Similar amounts fell in October 2005 and 2006. October 2000 had been wet (110 mm) and October 2002 dry (15 mm).
The total rainfall for the two months ending in October 2007 was rather low compared to the same two months in other years. At 54 mm, it was on the 19th percentile: that is, there has been less than 54 mm rainfall in September-October about one year in five. By contrast, the three months ending in October had rainfall above normal, and the last nine month period had rainfall well above normal. Most other periods, up to 48 months, have been slightly drier than normal. Just 2 mm extra per month would have made these last four years wetter than normal.

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.