Very Wet July 2012

The daily weather logWeather log July 2012.

As in June, most weather features in July were normal, except for very warm nights with the heavy rain in the second week. Sixteen mornings were frosty, one down to minus three degrees. There were several early fogs in the valley.
Of seven rain readings, most were heavy. But the 29.6 mm value included three days.

 Comparing July monthsClimate July 2012.

Other than rainfall, there is only one variable that is not on the July average: the subsoil temperature at 750 mm is again extraordinarily warm, at 16.9°, 3.2° above normal.
The rainfall total of 91.4 mm is in the 94th percentile. Only eight July months have ever been wetter. However, July 1984, at 171 mm, was nearly twice as wet. The 12-month total to the end of July (1020 mm) is extreme. In the last 50 years, only three 12-month totals have been higher: September and October 1998 and February 1984.


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 June 2012

Parametric plots of smoothed climate variables at ManillaTrends to June 2012.

June 2012 anomalies show a return to normalcy for rainfall and maximum temperature. Three moisture-related measures returned to the values of last winter: rather high cloudiness, rather low daily temperature range, and (strangely) rather low Dew Point. Daily min temp returned to the high positive anomaly last seen in 2010.
The subsoil became extraordinarily warm. (Why?)

Fully-smoothed data (in red) show that the 13-year record high monthly rainfall anomaly of November 2011 (+43.8 mm) was not beaten in December, as had seemed likely. The smoothed maximum temperature of December 2011 equalled the record cool anomaly of -1.96 degrees set in October 2010.

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.

Normal Weather in June 2012

The daily weather logWeather log June 2012.

Most weather features in June were normal.: much the same as last year and the year before. Even the frosts were normal. Eleven mornings were frosty, 7 below zero, and 2 below minus 2° (averages: 13, 8, and 2). The coldest morning, Sunday the 24th, was -4.0°. There were several early fogs in the valley but only that on the 24th stayed after 9am.
There were 8 rain days, the highest reading being 21.0 mm on the 3rd.

 Comparing June monthsClimate June 2012.

There is only one variable that is not on the June average: the subsoil temperature at 750 mm is extraordinarily warm, at 18.3°, 3.0° above normal.

The rainfall total of 45.8 mm is within 2 mm of the average (44.3 mm) and in the 60th percentile. Among totals for more than one month, only the 2-, 3-, and 4-month totals are below the median.


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.

 

Manilla’s Hot Days

I have used my 13-year weather record to find the number of hot days in each year and in each month. Earlier I did the same for frosty mornings. Because the summer, which has the most hot days, crosses from one calendar year to the next, I have begun each year at July.
I have called days warmer than 35° “hot days”, and days warmer than 40° “very hot days”.

Total hot days

The first graph shows the number of hot and very hot days in each year. The most hot days were in the year ’09-’10, which had 44; the fewest were in the year ’11-’12, which had only 4. The 13-year average is 26, but the number of hot days is quite different from year to year.

Counting only the very hot days, ’03-’04 had the most (6), and four years had none at all. On the average, two days exceeded 40° in a year.
Hot days each year, and seasonal distribution.

Months with hot days

The second graph shows how the number of hot and very hot days peaks strongly in January, with very few earlier than November or later than March. On average, Manilla’s summer has about 22 days warmer than 35°, while spring has 3, and autumn only 1.


The other graphs show how each year had a different pattern of hot days. The highest monthly peaks, each 19 hot days, came in January 2003 (following drought) and January 2007. Annual peaks also came in January in 2008 and 2012, but these peaks were extremely low: only 4 and 3 hot days. Continue reading

Manilla’s Frosts

I have a 13 year record that shows how frosty Manilla is, and how some years are frostier than others. My thermometer is on high ground, so people living where cold air collects will have had more frosts. However, my readings show changes from one time to another. As I do not have a thermometer in the grass, I have recorded a frost when my screen reading is below +2.2°.

There is a matching post for Manilla’s hot days.

Total frosts

The first graph shows the number of frosty mornings in each year. The most frosts were in the years 2004 (68) and 2006 (70); the fewest were in the years 2007 (43) and 2010 (44). The 13-year average is 54.
The graph also shows the number of mornings colder than zero, minus two, and minus four degrees. On the average, these occurred on 26, 7, and 1 mornings per year. For those colder than zero degrees, 2006 was again the frostiest, but 2002 was also very frosty. Counting only the most severe frosts (below minus two or minus four degrees) 2002 was the frostiest year. It had the coldest mornings: -5.1° on both the 2nd and 11th of July.Frosts each year, and seasonal distribution.

Frosty months

The second graph shows how most frosts come in the winter months, especially July, with some frosts in autumn, but few in spring and none in summer. Few come before Anzac Day (25th April) or after Labour Day (first Monday in October in NSW).


The graphs below show that each year was different. The drought year 2002 had the highest number of frosts in a single month: 27 in July – half of all frosts in that year. By contrast, the 70 frosts of 2006 were spread through the months of winter and autumn: there were more frosts in June and August than in July. Continue reading