February 2017 had the hottest day

February 2017 was a month of extreme heat and hardly any rain.

Rainbow

No-rain Rainbow

The temperature rose to 44.9° on the 11th, the highest reading in this record from 1999. The next day, at 43.8°, was the next highest, beating readings of 43.7° on 3/01/2014 and 43.2° on 12/01/2013. These extremely hot days were part of a long heat-wave. Every day reached above 30° for 64 days up to the 19th, and the average weekly temperature was above 30° (4° above normal) from the 1st to the 15th.
Nights also remained warmer than normal until, abruptly, the temperature fell to 9.5° on the 20th: the 4th coldest February night! After that, day and night temperatures were normal.
Rain showers were seen frequently, but the only daily readings (unofficial) were 1.1 mm on the 20th and 3.0 mm on the 27th.

Weather log February 2017

Comparing February months

This was by far the hottest February of the new century, with highest values of all three temperatures: mean maximum temperature (36.8°), mean average temperature (28.4°) and mean minimum temperature (20.0°). Subsoil temperature was normal.
While cloudiness was normal, a rather low dew point and rather wide daily temperature range reflect low moisture, while the rainfall was very low indeed.
The estimated monthly rainfall total of 4.1 mm exceeds that of just a very few February months: 1901 (2 mm), 1932 (3 mm), and perhaps 1923 and 1938 (both 4 mm), but no others. However, this extremely low rainfall for the month has not brought any serious rainfall shortages for totals of more than one month. The four-month total of 123 mm is at the 17th percentile, which is not even as bad as the five-year total (2844 mm) which is at the 14th percentile.

Climate for February 2017.


Data. Rainfall figures are usually from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. However, the gauge ceased recording four months ago (8/10/16), and this month’s readings are from my non-standard gauge. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

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3-year trends to February 2017

Parametric plots of smoothed climate variables at Manilla
“Extreme heat with little rain”

3-year trends to February 2017.

February raw anomaly data (orange)

In February 2017 days became extremely hot and rainfall very low. The subsoil temperature rose from low to normal.

 Fully smoothed data (red)

Fully-smoothed values are now available for the winter months (June, July, and August) of 2016. That winter, as daily maximum temperature fell through normal values, a maximum in moisture was shown by maxima in rainfall, cloudiness, and dew point, and a minimum in daily temperature range. None of the smoothed values was extreme; in fact, the dew point remained on the dry side of normal.
Not only daily maximum temperature anomaly fell during the summer. Both the daily minimum temperature anomaly and the subsoil temperature anomaly also fell. The smoothed daily minimum temperature anomaly had just reached a record high value in May, and was still above normal as the summer ended.


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 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.

February 2016: hot, dry days

Photo of cooba blossom

Cooba in February

Weekly average temperatures began 2 or 3 degrees low, but ended with a long warm spell 3 degrees high, that extended into March. Days were especially hot, with the 26th reaching 41.5°, the equal second hottest February day. Nights were seldom very warm, and the early morning of the 26th was 25° cooler than the afternoon.
Few days were cloudy, none of them late in the month
Rain fell only on the 3rd, as three heavy showers of 7mm, 27mm and 13mm. The second shower, at 5pm, had the most intense rain of the new century: 27 mm in less than 27 minutes. Bureau of Meteorology data show that such a half-hour storm, yielding 1 mm of rain per minute, has only a 10% chance of happening here in any year. It is a “one in 10 year event”.

Weather log February 2016

Comparing February months

While the average temperature for the month (25.8°) was normal, the mean daily maximum, at 34.7°, was the hottest for February. A rather low mean daily minimum, (16.8°) made the daily temperature range a desert-like 17.9°. This is the widest February value, 3.5° wider than normal.
Other signs of dryness were the low early morning dew point (10.8°) and very few cloudy mornings (17%).
The total rainfall of 47mm was below the average of 67 mm, but right on the median 50th percentile: just half of all February months have been wetter. Again, there are no serious rainfall shortages for totals for any number of months.

Climate for February 2016


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 February 2016

Parametric plots of smoothed climate variables at Manilla
“February 2016: suddenly dry”

Trends to February 2016

February raw anomaly data (orange)

In February 2016, raw values for anomalies moved completely across the graphs, from cool and moist in January, generally to hot and dry in February. As in a desert, days became very hot, skies very sunny, and the daily temperature range extreme. Rainfall and dew point were only moderately low, while daily minimum temperature abruptly fell very low, and subsoil temperature remained very low.

 Fully smoothed data (red)

With data for August 2015, fully smoothed data is complete for winter 2015. Most anomalies for the season were quite small, but were moving away from cool and moist.

Trend lines on the graphs

Manilla’s climate often oscillates along the blue trend lines from bottom left (cool, moist) to top right (hot, dry) on the graphs. The climate can also vary along other axes.
In this time-frame the sub-soil temperature anomaly (bottom right graph) is leading the daily maximum temperature anomaly by several months. That produces a clockwise looping pattern. The daily minimum temperature anomaly (bottom left graph) sometimes moves with the daily maximum temperature anomaly, and sometimes moves against it. When against it, as from July 2013 to October 2014, the climate swings between Continental, with hot days and cool nights (as October 2013), and Maritime, with cool days and warm nights (as May 2014). Current raw data for January and February 2016 show a large swing from Maritime to Continental.


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 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.

3-year trends to February 2015

Parametric plots of smoothed climate variables at Manilla
“February 2015: very dry”

Trends toFebruary 2015

  February raw anomaly data (orange)

In February, most anomalies moved back towards “droughts” from the “flooding rains” values of January. Rainfall became extremely low, but daily maximum temperature did not rise as far as “normal”.
Exceptionally, February daily minimum temperature and subsoil temperature became very low.

Fully smoothed data (red)

The latest fully-smoothed data anomalies (August 2014) complete the winter of 2014. Through the winter season, most values were static and near normal. (Dew point, like most recent values of that variable, was 3 degrees lower than normal.)


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 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.

February 2015 a very dry month

Photo of a baby Kookaburra

Baby Laughing Kookaburra

After a very cool first week, normal temperatures returned, both by day (33°) and by night (18°) . Early on, most mornings were sunny. Later, many were almost overcast, but only three days had light rain, with a maximum of 3.4 mm.

Weather log  February 2015

Comparing February months

Most of the last seven February months have been unusual in some way. This month was very dry, with near-record low rainfall and very low humidity. By contrast, February 2012 was very wet, as well as very cool. Both 2011 and 2014 were very warm, but 2011 was also very cloudy and humid. February 2013 was the coolest, without being wet like 2012.
The total rainfall of 7.6 mm this month was very low (6th percentile): this was the 8th driest February, and the driest since 1989, which (like 1974) had 7.0 mm. Still, taking rainfall totals for groups of months, only the 24-month total (985 mm) is a serious shortage, in the 9th percentile.

Climate forFebruary 2015


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.

With the retirement of the Post-master, Phil Pinch, the future of rainfall observations at Manilla Post Office (055031), kept for 132 years since March 1883, is uncertain.

February Climate Anomalies Log

Heat indicators log for February

This post is the twelfth in a set for the 12 calendar months that began with March. Graphs are sixteen-year logs of the monthly mean anomaly values of nine climate variables for Manilla, NSW, with fitted trend lines. I have explained the method in notes at the foot of the page.

Raw anomaly values for February

Extreme values of February anomalies were as follows:

Daily Maximum Temperature Anomalies (3) -4.2 deg: February 2008; -3.3 deg: February 2012; -3.3 deg: February 2013;
Daily Mean Temperature Anomalies (1) -3.3 deg: February 2008;
Rainfall Anomalies (1) +120 mm: February 2012;
Dew Point Anomalies (2) -4.6 deg: February 2014; -4.6 deg: February 2015.

Trend lines for February

Heat Indicators

All heat indicator quartic trends began slightly low and ended slightly low. They had a low peak about 2004, and a trough later. The trough was deepest and earliest for daily maximum temperature (2011), followed by daily mean temperature in 2012, daily minimum temperature in 2014, and subsoil temperature in 2015 or later.

Moisture indicators log for February

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