January 2017 had the hottest night

Cumulus congestus at 130 km

Showers at 130 kilometres

The daily weather log

In the early morning on the 14th, the minimum temperature was 28.2°, the hottest night in this record from 1999. That beat 27.8° set on November the 28th, 2009. Of January months, only this month and January 2006 had no nights as cool as 15°. There were no cool days either: like January 2002, no days were as cool as 30° (and none since 16/12/16). However, only two days this month went over 40°: the 12th with 41.4° and the 13th with 41.2°. That hardly compares with January 2003, which had five. The weekly average temperature was over 30° (4.7° above normal) from the 11th to the 15th. Late in the month, it got as low as 28°, then climbed again.
Showers and storms brought rain on 8 days, but the maximum was only 19.8 mm.

Weather log January 2017

Comparing January months

As in December, this was the hottest January of the new century. It easily beat January 2013 in mean daily maximum (36.4°), mean average (28.7°), and especially mean daily minimum (hot nights: 21.0°). As this months days and nights were both so warm, the daily temperature range was quite normal (15.4°).
Contradicting the high air temperatures, the subsoil temperature was below normal, at 25.1°.
The month was more humid than usual. Afternoon humidity, at 36%, was the highest January value in twelve years (normally 28%), and early morning dew point was the highest in eleven years.
The monthly rainfall total of 48.5 mm is in the 30th percentile, well below the average of 87 mm. Rainfall totals for more than one month still show no shortages. The 48-month total of 2320 mm (down 280 mm) has the lowest percentile value (23rd percentile) as a legacy of dry months around 2013.

Climate for January

 


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.

3-year trends to January 2017

Parametric plots of smoothed climate variables at Manilla
“January 2017 very hot”

3-year trends to January 2017

January raw anomaly data (orange)

In January 2017 both days and nights became even hotter. While rainfall was low, dew point was high.

 Fully smoothed data (red)

At the time of the latest fully-smoothed anomalies, in July 2016, most variables were still moving towards towards cool and moist.


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.

January 2016: moist again

Photo of Senna-bush

Jewel-box Cassia

Unlike December, this month saw varying temperatures. The week around the 7th was quite cool. The maximum on the 3rd reached only 22.3°, but worse was to come. The 15th reached only 21.1°: equal coldest January day in the new century (with 31/1/2001). It was more than 12° below normal, and that happens less than once in a year. There was also one very hot day above 40°, which is the normal number for January.
Rain fell, mainly as showers, on ten days spaced through the month. The higher readings were 28.4 mm on the 6th, 24.2 mm on the 23rd, and 27.6 mm on the 24th.

Weather log January 2016.

Comparing January months

Like January last year, this month could be called “moist”. It was cloudy, and the rather cool days were only 14° warmer than the nights.
The total rainfall of 104.7 mm was well above the average of 87 mm, and in the 72nd percentile. Again, there are no serious rainfall shortages for totals for any number of months. In fact, totals for 2-, 3-, 4-, 5-, and 6-months are very high.

El Niño

Manilla’s climate is now out of step with the El Niño – Southern Oscillation (ENSO). This “super” El Niño has not brought dryness here, and the dryness in January 2014 (for example) came at a time without an El Niño.

Climate for January 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 January 2016

Parametric plots of smoothed climate variables at Manilla
“January 2016: moist again”

Trends to January 2016

January raw anomaly data (orange)

In January 2016, raw values for nearly all anomalies moved well towards the cool and moist corner of the graphs.

 Fully smoothed data (red)

In the latest month with fully smoothed data (July 2015) anomalies were quite small, but were moving towards warm and dry. Partially smoothed data points for more recent months show that the warm and dry “El Nino” influence on values around October and November was smaller than it seemed at first. In particular, rainfall did not go below the “normal” range, but the anomaly of daily minimum temperature rose quite high.


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.

January 2015: cool rainy days

Crepe myrtle shrubs

Crepe Myrtles in Arthur Street

Only five days were warmer than average. The final five days and four nights were very cool, taking the weekly average (normally the hottest of the year) down to five degrees below normal. (This would be normal for the end of March, not January!) There were fifteen rain days, equalling the 125-year record number for January, set in 1941. Rain was spread evenly through the month, with the highest reading 29.2 mm on the 2nd.

Weather log January 2015

Comparing January months

The mean daily maximum temperature (31.4°) was well below the average of 33.8°. Since nights, at 17.6°, were near normal, the daily temperature range was the record narrow value for January of 13.8°.
The dew point (humidity) returned to a normal value of 12.9°, after last January’s arid 6.9°. Subsoil temperature (25.3°) fell to normal after two January months above normal.
The total rainfall of 117.4 mm was in the 75th percentile, well above the average of 87 mm. This clears all shortages in rainfall totals for groups of months. The lowest percentile value remaining (15th) is for the 18 month total of 746 mm.

Climate for January 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.

January Climate Anomalies Log

Heat indicators log for January

This post is the eleventh 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 January

Extreme values of January anomalies were as follows:

Daily Maximum Temperature Anomalies (1) -3.7 deg: January 2012;
Rainfall Anomalies (5) -70 mm: January 2002; -75 mm: January 2003; +80 mm: January 2004; +94 mm: January 2006; -85 mm: January 2014;
Dew Point Anomalies (2) +3.1 deg: January 2006; -7.4 deg: January 2014.

Trend lines for January

Heat Indicators

All heat indicator quartic trends began low and ended slightly high, and had a low peak in 2003, -05, or -06, and a shallow trough about 2012.

Moisture indicators log for January

Continue reading

3-year trends to January 2015

Parametric plots of smoothed climate variables at Manilla
“January 2015: rainy cool days”

Trends to January 2015

 

January raw anomaly data (orange)

Anomalies for all variables except subsoil temperature moved across the graphs, from “droughts” in November to “flooding rains” in January. Subsoil temperature had been normal from February to December (11 months!), then became cooler than normal in January.
Most raw anomaly values for January were close to the fully-smoothed anomaly values of the La Niña-affected cool summer of 2012. This month’s daily temperature range was even narrower, and the subsoil temperature lower, but the daily minimum temperature was not so low.

Fully smoothed data (red)

The latest fully-smoothed data anomalies (July 2014) were near normal. (Dew point, like most recent values of that variable, was 3° 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.