March 2015 was hot

Photo of bird in a gum tree

Blue-faced honeyeater in a White Box tree

March had 5 hot days over 35°: more than January (2) or February (3), but less than December (7) or November (10!). On the 20th the temperature reached 40.0°, making it the hottest March day of the century, 10.2° above normal. It came in a warm spell, with a weekly mean temperature 3.6° above normal. Some days had extremely low humidity, with afternoon values below 10%. The morning dew point on the 28th, minus 4.2°, was the lowest March value.
There were five rain days, with the highest reading 22.0 mm on the 12th.

Weather log for March 2015

Comparing March months

The average daily maximum temperature, at 31.8°, was the hottest of any March in this short record. It was almost the same as in each of the months of this summer, but not as high as that of last November (33.9°). The daily mean temperature (23.6°) was also the highest for March, just beating the 23.4° of March 2000. Night temperatures were normal, making the daily temperature range wider than normal. The mean early morning dew point of 8.3° was a record low value.
The total rainfall of 35.8 mm, while well below the average of 53 mm, is quite normal. It is in the 46th percentile: nearly half of all March totals were lower. Among rainfall totals for more than one month, there is little change. Again, the only serious shortage is in the 24-month total, which is now in the 5th percentile.

Climate for March 2015


Data. Rainfall data up to 26/3/15 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 March 2015

Parametric plots of smoothed climate variables at Manilla
“March 2015: hot”

Trends to March 2015

 March raw anomaly data (orange)

In March, the daily maximum temperature anomaly became very high (+1.6 degrees), but not nearly as high as the raw value had been in November (+5.1 degrees). Most other anomalies moved up the graphs towards “droughts” but not beyond normal values. Dew point remained as low as in February, and rainfall returned from very low to normal.

Fully smoothed data (red)

The latest fully-smoothed data anomalies (September 2014) moved a little towards “droughts” from the near-normal values of the winter.


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.

Summer 2014-15 on average

Wildflower photo

Commelina cyanea in Monash Street

This summer, January was no warmer than December or February, and none of these months was as warm as November! The number of hot days (over 35°) had a similar pattern that “sagged” in midsummer: Oct: 4 days; Nov: 10 days; Dec: 7 days; Jan: 2 days; Feb: 3 days; Mar: 2 days (in the first week). There were no very hot days over 40° this summer, although there had been three in spring.

A very cool spell from late January to early February had day and night temperatures 4.5° degrees lower than normal. Humidity was also low at that time and earlier, in mid-December.

Weather log for summer 2014-15

By most measures, this was a normal summer. Compared with the 21st century average, the daily maximum temperature and the daily temperature range were both just one degree low, and skies were a little more cloudy. The dew point (humidity) was low, but much higher than last summer.

The rainfall of 224 mm could hardly be more “normal”. It lies between the 125-year average of 227 mm and the 125-year median value of 221 mm. Summer rainfall totals like this also occurred in 2002-03 (227 mm) and 2008-09 (229 mm). Historically, summer rainfall totals in the “normal” range from 220 mm to 230 mm occurred in 1902-03, 1917-18, 1936-37, 1948-49, and 1957-58.

Climate for summer 2014-15.


Data. Rainfall data is from Manilla Post Office, courtesy of the Post-master, Phil Pinch. I thank Phil for his help over the years. When he retires this March, there is some uncertainty about the future of rainfall observations that have been maintained for 132 years since March 1883.

 Temperature, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.

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.