Tag Archives: July

July 2010 Rain Twice Average

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log July 2010 Manilla

July began cold. The 2nd, with a maximum temperature of 9.1°, was the coldest July day in the record from 1999. The only two colder days were: 8/06/07 (8.8°), and 20/06/07 (8.3°).

Two warm spells followed, marked mainly by nights that were very warm for mid-winter. The minimum on the 12th (11.8°) was 10° above normal, and that on the 31st (13.5°) was 11.3° above normal. Colder nights included twelve mild frosts, the fewest on record.
There were 13 rain days spread through the month. The reading of 17.2 mm on the 29th was topped by 34.2 mm on the 31st.

“Normal Temperature”

Each Manilla monthly weather graph has dashed curves to show the temperatures that are normal for each day of the year. They are harmonic curves matching 10-year averages from March 1999. On this July graph, the lowest values are marked with a double “X”. Winter cold is due to lack of heat from the sun, which yields least heat on the 21st of June (the winter solstice). On that day the sun is lowest and shines the shortest time. However, it takes many days for the air to cool down. On average, the coldest day in Manilla comes 17 days later (July 8th) and the coldest night 22 days later (July 13th). Manilla’s coldest day and night follow the solstice with an unusually short lag time. (See Wikipedia: “Seasonal lag”.)

See the monthly weather report for January 2010 for the highest normal temperatures of the year. These relationships are shown on a graph here.

Comparing July monthsClimate July 2010 Manilla

Due to cloudy nights, the mean daily minimum temperature (4.6°) was by far the highest in the 12-year record for July, and 2.4° above the average. Because the mean maximum temperature was normal (16.9°), the mean average temperature was also high (10.8°). The mean daily temperature range (12.3°) was the narrowest in the July record.

Very high humidity was shown by a mean early morning Dew Point of 4.6°, higher than any since July 1999 (5.7°). The percentage of cloudy mornings (61%) was the highest, not only for July months, but for any month in this record. Nineteen mornings were completely overcast.
The rainfall of 79.8 mm is in the 90th percentile for July: only 12 July months have been wetter. It is close to double the long-term average of 41 mm. As a result, total rainfalls for the last two months and three months are now above the median. No serious rainfall shortages remain. The worst shortages are far from serious: the 15-month and the 9-year totals are both in the 14th percentile.

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.

July 2009 getting short of rain

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log July 2009

Apart from a scarcity of rain, and an abundance of cloud, the weather in July was very much as usual. One day reached 23°, another only 12°. There were 18 frosts (normally 17), but no night was colder than -2° (normally 4 nights are). Fog filled the valley on the 28th.
There had been twenty-three days without 5 mm of rain when 9 mm fell on the 16th. In six rain days the month’s total was 21.3 mm. This is well below the median for July (35 mm): it is in the 25th percentile.

 Comparing July months

Climate July 2009

All mean daily temperatures for the month were normal.
There is a serious shortage of rain in the five months to date: the total of 138 mm is on the 10th percentile. Five-month totals below the 10th percentile are rare in recent years: July 2008 (9th percentile), August 2006 (9th), May 2005 (5th) and September 2003 (7th).
(Very much drier 5-month conditions prevailed in 2002: November had a severe rainfall shortage (in the 2nd percentile) while July, August, September and October had extreme rainfall shortages, in the first percentile. September 2002 had the lowest 5-month total (61 mm) in 75 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.

 

July 2008: more cloud, less frost

Posted in Manilla NSW, Monthly weather by

The daily weather log

Weather log July 2008

With 52% cloudy mornings, this was the cloudiest July (and the fifth cloudiest month) in a decade.
There were no long warm or cold spells, so the seven-day mean temperature scarcely changed until the cooler final days. Yet each day’s temperatures were quite different from the day before. Wednesday the 9th was the 4th coldest day of the decade. It reached only 9.8°, and Monday the 28th, at 11.3°, was not much warmer.
Five nights were warmer than 8°. They were separated by cold nights, but there were only fourteen frosts, the coldest, on the 12th, being 2.7°. Widespread fog on the 15th did not lift until 11 am, and there was thick fog in the valley on the 26th.
Eight rain days were scattered through the month. The wettest day had 9.4 mm, and the total was 33 mm.

 Comparing July months

Climate July 2008

The mean daily maximum and daily mean temperatures for the month were normal but, on the average, nights were warm. As a result, the mean daily temperature range, 13.6°, was the narrowest in ten July months. Sunny, frosty, droughty July 2002 had a range of 18.5°: more than 30% wider! (The month with the narrowest mean temperature range for the decade was June 2007, with 10.9°. That was also the cloudiest month.)

July usually has about 17 frosts. This month’s total of 14 made it the least frosty July this century. July 1999 had only 13 frosts, with none below -2°.
Humidity (early morning dew point) was normal for the time of year.
The rainfall total is not far below the average: 33 mm is in the 46th percentile for July. The total for this June and July together (98 mm) is better than usual: in the 52nd percentile of two-monthly totals. Not so good are the three-monthly total (112 mm) in the 30th percentile and the four-monthly total (132 mm) in the 20th percentile. Worse, the five-month total (134 mm) is only in the 8th percentile, due to the 2 mm rainfall of March. The six-month total is much better (in the 29th percentile). Rainfall totals for longer periods are 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.

 

Fine cold days in July 2007

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log July 2007

Most days in July were cooler than normal. The first chart shows cold days persisted for more than a fortnight. The coldest, on the 16th, reached only 10.5°, which is 5° below normal. However, the weather was mainly pleasant, with more fine days and fewer cloudy days than usual.

There were warm nights at each end of the month, including one 7° above normal. In the middle, there were thirteen frosty nights in a row (below +2.2 degrees in the thermometer screen). The lowest temperature for the month was minus 4.4°. There were 17 frosts in total; far fewer than the 28 frosts of July 2002. (Note added in 2014: Up to, and including 2011, minima have been below minus 4° only sixteen times:  June 2000 (5), June 2002 (1), July 2002 (6), July 2003 (2) and July 2007 (2).)

With both days and nights being so cold, the weekly average temperature went as low as 4.7° below normal on the 17th.

There were seven rain days, which is normal, but the highest reading (on the 1st) was only 4.2 mm.

 Comparing July monthsClimate July 2007

This July had colder daytime maximum temperatures than any July in the last seven. Night-time minimum temperatures were also a bit on the low side. July 2002 stands out from the others. It had by far the lowest night-time temperatures in these years: three degrees below the average. Cloudiness was low in both 2002 and 2007.

The month’s rainfall of 9.0 mm is quite low, in the 12th percentile for July. However, there have been few dry months recently, so no totals for more than one month are as low as the 20th percentile.

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.