December 2013: air still dry

The daily weather logWeather log December 2013.

The month began cool, including two nights at 6.9°, the coldest December nights in this record. Later it became very warm, with one night of 24.0° and one day of 40.2°. Spells of sunny weather were separated by five rainy days.
The relative humidity on the afternoon of the 29th was the record low value of 4%, as on 10/1/13 and 13/8/13. (These values may be wrong. Few hygrometers can be read so low.)

Comparing December monthsClimate December 2013

This December was warm: just slightly cooler than December last year, and very much warmer than those of 2010 and 2011. Extremely dry air brought a new record low December mean morning dew point of 8.8°.
Subsoil temperature (25.7°) remained 1.5° above normal.
The total rainfall of 45.6 mm was in the 28th percentile, well below the average of 74 mm. However, there are still no serious shortages in rainfall totals for more than one month.

The Year 2013

This was one of the warmer years in the new century (but much cooler than 2009). It had the driest air, with a mean early morning dew point of 5.4°, 1.5° below average. The air has become drier each year since 2010.

This year also had the highest subsoil temperature: 22.1°, 1.9° above average.
Extremely high rainfall in June (98mm) was balanced by very low rainfall in August (6.4mm) and October (15mm), for a low annual total of 576 mm, in the 37th 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.

Spring 2013 hot and dry

 

Weather log spring 2013.Through most of this spring season, days were hot and sunny, and the humidity and dew point were very low. This changed for the final three weeks, when two-thirds of the season’s rain fell, and the weather was cool and humid.
Along with 2002 and 2009, this was one of three hot springs this century. However, this spring had cooler nights. The springs of 2002, 2012 and 2013 were the driest, counting humidity and cloud as well as rainfall. This spring had the lowest humidity by far, and last spring the second lowest. Low humidity means crops and animals (and people) need more water.
The total rainfall (130 mm) was in the 36th percentile for springs. Rain fell on only 13 days: more than in spring of 2002 (9 days), but fewer than in 2003 (15) or 2012 (16).Climate spring 2013

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.

Rain came back in November 2013

The daily weather logWeather log November 2013

By November the 11th, there had been only 70 mm of rain since the deluge in June. The humidity had been getting lower by the month. From that day, rain and high humidity returned. Days and nights became cooler than normal, with more cloudy skies. Most of the seven wet days were showery, but the 29th had steady rain.

Comparing November monthsClimate November 2013.

The weather change on the 11th returned most monthly average values closer to normal. However, despite the rain, this was still an “Arid” month, with a record low November mean morning dew point, a wide daily temperature range, and few cloudy mornings. The mean subsoil temperature (23.8°) was 1.9° above normal, exceeded (in the 21st century) only by 24.7° in November 2002.
The total rainfall of 95.6 mm was in the 80th percentile, well above the average of 67 mm. This disposes of all serious shortages in rainfall totals. The worst figure now is the 5-month total of 166 mm, which is 56 mm below normal (19th 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.

Extremely Arid October 2013

October’s climate was even more desert-like than this September or October last year. Afternoon humidity (normally 30%) was only 13.1%, which is the lowest value in ANY month in the last eight years. The early morning dew point of 0.5° was the lowest October value this century, and 7.8° below normal, a record anomaly value for any month. This very dry air often came with strong winds. Most of north-west NSW was affected.

The daily weather logWeather log October 2013.

The second of two warm spells brought weekly temperatures three degrees above normal. Each warm spell ended with a night above 20°. Three mornings from the 25th were exceptionally dry, having dew points of minus 7.2°, minus 8.0°, and minus 7.6°. (The record: minus 9.3° on 17/5/11.)
There were three rain days: the 2nd with 13.8 mm, and the 18th and 30th with 0.6 mm each.

Comparing October monthsClimate October 2013.

October’s days were not quite as warm as in 2007. Dryness was marked by low rainfall, little cloud, and wide daily temperature range, but most remarkably by the record low dew point and relative humidity.
At 21.0°, the subsoil was warmer than in any other October month. It was 1.6° above normal.
The total rainfall of 15.0 mm was in only the 12th percentile, far below the average of 58 mm. The three and four month rainfall totals (41 mm; 71 mm) are now severe shortages, in the 3rd and 4th percentiles.


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.

Desert-like September 2013

September was an exceptionally arid month: like the Sahara Desert!

The daily weather logWeather log September 2013

Most days were warmer than normal, with the first 30-degree day of spring coming two weeks early, on Sunday the 8th. Weekly average temperatures showed two warm spells three degrees above normal. Half the mornings had completely blue skies. The air was extremely dry: the dew point early on the 12th was 6.3 degrees below zero, and all the afternoons of the final week had relative humidity below 10%.
Briefly, from the 16th to the 18th, the weather was cooler and more humid, with 19.4 mm of rain.

Comparing September monthsClimate September 2013.

Nearly all the monthly weather values were exceptional. As noted on the graph, they were record September values (from 1999): highest maximum and mean temperatures, widest daily temperature range, lowest dew point and fewest cloudy mornings. (The September daily minimum temperature had been higher: 9.7° in 2002, and 8.2° in 2010.)
The total rainfall of 19.4 mm is half the average of 41.2 mm. It is in the 28th percentile. The two and three month totals are now serious shortages, in the 6th percentile. The 24 month total (1508 mm) and 36 month total (2231 mm) are still very high.


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.

Winter 2013 Warm

Weather log winter 2013

This winter, June was very cloudy and wet, July was very warm, and August was warm and dry. This pattern was common across northern NSW.
There were only 29 frosts, well below the winter average of 44, and fewer than in winter 2010 (32).
All winter average temperatures were above normal: daily max (18.9°), up by 0.8°; daily mean (11.6°), up by 1.2°; daily min (4.3°), up by 1.6°. In each case, winter of 2009 had been slightly warmer. As in last winter, the subsoil temperature was very high: 17.0°, which is 2.7 °above normal for winter in the decade from 1999. In that same decade, only 34% of winter mornings were cloudy; this winter’s value of 43% has become normal since.
The winter rainfall total of 134 mm is just above the average (125 mm) and in the 62nd percentile.Climate Winter 2013

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.

Dry, Warm August 2013

The daily weather logWeather log August 2013.

The month had no extremes of heat or cold. Frosts (10) were almost as rare as in August 2011 (9). Some overcast skies came with 5.8 mm of rain on the 17th then, from the 25th, there were five cloudless mornings bringing very warm weather. Altogether, only three days had rain (usually 6).

Comparing August monthsClimate August 2013.

After July having temperatures two degrees above normal, this month’s maximum was only one degree up, and the minimum just on normal. While the air was not as extremely dry as it was last August, the morning dew point was still very low: 2.7 degrees below normal. In contrast, the subsoil temperature remained extremely high, at 16.6°, 2.7° above normal.
Total rainfall is far below the average of 39.5 mm. At 6.4 mm, it is in the 9th percentile: since 1888, only 10 August months have been drier. In totals for two months and more, there is no serious shortage of rainfall, although nearly all totals up to 18 months are now below the median. Totals for all longer periods (up to 360 months) are above 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.