Extremely warm July 2013

The daily weather logWeather log July 2013.

There were three warm spells and no cold spells in July. Fourteen days went over 20 degrees, instead of the usual four. There were only eleven frosts, the fewest in 15 July months (usually 17). In five rain days, two high rainfall figures came on the 20th (19.2mm) and the 21st (9.6mm).

Comparing July monthsClimate July 2013.

After June’s extreme cloudiness and rain, July was very near to normal in everything but temperature. The average values of daily maximum, daily minimum, and daily mean temperature were all just under two degrees above normal. The daily maximum and daily mean are 15-year record high values, but the daily minimum had been higher in July 2010: 2.4 degrees above normal.
(Note: My “normal” is the ten year average from March 1999. For the official normal period 1961-1990 there are no Manilla figures (except rainfall). This month’s very high temperatures would be (perhaps) just over 2 degrees above the 1961-1990 average.)
Rainfall, at 29.8 mm, is in the 43rd percentile, a bit below the average (41.1mm). Rainfall totals for 24 months and more are very high. This accounts for the rare appearance of water flowing locally in Greenhatch Creek.


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.

3-year trends to April 2013

Parametric plots of smoothed climate variables at Manilla

“Back to warm and very dry”Trends to April 2013.

In April the raw value of maximum temperature anomaly became high and (indicating aridity) those of rainfall, dew point, and minimum temperature extremely low, and that of temperature range extremely wide. Cloud remained normal, and subsoil temperature high.

Fully-smoothed data points (red) for October 2012 continued to move towards higher maximum temperature, but scarcely moved further towards drought.

Note: 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.

January 2013 very hot, then wet

The daily weather logWeather log January 2013.

Days were sunny and extremely hot in the first three weeks. Saturday the 12th had the highest temperature on this record: 43.2°. Later, days were cloudy, and the maximum temperature on the 28th was only 21.3°. That was 12.6° below normal, and the second coldest January day. Most nights were warmer than normal, helping to make the weekly average of 30.3° on the 10th the second hottest, after a week in November 2009.
Only a few showers had fallen until the 27th, when ex-tropical cyclone Oswald brought 89 mm in three days of steady rain.

 Comparing January monthsClimate January 2013.

Unlike recent arid months, March was near normal in day-time temperature, humidity and cloudiness. Nights were very warm, however .

The total rainfall of 101.6 mm is almost twice the March average of 53 mm, and in the 85th percentile. March has been wetter in nineteen years, including 2001 (103 mm) and 2007 (114 mm). Taking rainfall totals for more than one month, the greatest shortages are not serious (i.e. not below the 10th percentile). The twelve-month total (469 mm) is in the 14th percentile. Other totals have higher percentile values, and most totals for 30 months or more are above normal.


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.

 

December 2012 Hot, with Rain

The daily weather logWeather log December 2012.

As in November, most days this month were warmer than normal. The 1st, at 40.6°, was the equal hottest December day on this record, with 30/12/05.
Afternoon values of Relative Humidity fell to 7 percent on the 15th and 16th.
Rain was recorded on nine days, totalling 97.4 mm, with the highest reading 29.8 mm on the 26th.

 Comparing December monthsClimate December 2012.

Days this month, at 33.3°, were not quite as hot as those of December 2005 (33.7°). Nights this month were warm (17.5°), but not nearly as warm as those of December 2009 (18.6°). In stark contrast, December 2011 was several degrees cooler.
The mean early morning Dew Point of 11.7° shows the air is almost as dry as it was a year ago. Since then, the air has been even drier, with an extremely low morning Dew Point of 1.7° in October.
The sky was less cloudy than in any of the last five Decembers.
The rainfall of 97.4 mm is high, in the 72nd percentile for December. This defers all concerns about rainfall shortages: even the five-month total of 190 mm is in the 25th percentile.

The Year 2012

In 2012, rainfall was extremely high in February, April, and July, but extremely low in August and October. The total for the year (669 mm) was a little higher than the long-term mean of 652 mm, but a lot lower than last year’s 837 mm.
By other measures, Manilla’s climate drifted during the three years 2010, 2011 and 2012, from a humid coastal type to an arid inland type. In 2010 day temperatures had been very low (24.6 degrees), and night temperatures high (11.2 degrees), as would happen on the coast. By 2012, day temperatures had risen to normal (25.5 degrees), and night temperatures had fallen very low (9.6 degrees). A typical day in 2010 had the very narrow temperature range of 13.4 degrees, while a day in 2012 had a range of 15.9 degrees.
In the same way, 2010 had been extremely cloudy and humid, while 2012 had normal cloud and extremely low humidity. Subsoil temperature (750 mm) rose from a low value of 19.6° in 2010 to a record annual high of 21.6° in 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.

 

Warm, Dry November 2012

The daily weather logWeather log November 2012

Most days this month were warmer than normal. As last seen in 2002, no November daily maxima were below 25°. The month ended with a weekly average temperature nearly seven degrees above normal.
Seven afternoons had extra-ordinarily low humidities below 10 percent, and eight mornings had very low dew points (below 5°).
Rain came mainly as showers, totalling only 48.2 mm in seven rain days.

 Comparing November monthsClimate November 2012.

Warm temperatures this month were far lower than in November 2009, when Manilla and other places suffered a heat wave.

Very dry air is shown by the low mean early morning dew point of 8.8°. This is the lowest November value in 14 years, below the 1999 value of 9.6°. However, October’s value of 1.7° was very much lower.
The rainfall of 48.2 mm is in the 35th percentile for November, well below the average of 67 mm. The four-month rainfall total (92 mm) and the nine-month rainfall total (317 mm) are serious shortages, in the 8th and 9th percentiles. The 15-month total is still over a metre, which is keeping pools of water in the bed of Greenhatch Creek.


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.