At Ferny Grove, overnight temperatures were over 1 ºC above average and the highest in 11 years. Daytime temperatures were close to average and the lowest in 5 years. Rainfall was above below average and was the highest in 10 years. Mean relative humidity was above average, mean dew point was above average and mean air pressure was below average. There were 4 thunderstorms (3 thunder days).
Monthly mean daily minimum temperature: 20.8 ºC, 1.6 ºC above average and 1.2 ºC higher than same month in 2019. This is the second highest on record for December and the second highest since the current record high of 21.1 ºC in 2009.
Monthly mean daily maximum temperature: 30.3 ºC, 0.3 ºC above average and 2.7 ºC lower than same month in 2019. This is the equal lowest for December since 30.3 ºC in 2015.
Monthly mean temperature: 25.6 ºC, 1.0 ºC above average, 0.7 ºC lower than the same month in 2019.
Lowest temperature: 16.6 ºC on 27 December 2020 at 4:46 AM. Same month in 2019 was 14.4 ºC. This is the equal highest on record for December, equalling the current record high of 16.6 ºC in 2009 on 3 December.
Highest temperature: 35.9 ºC on 6 December 2020 at 11:38 AM. The same month in 2019 was 42.8 ºC. This is the lowest monthly maximum temperature for December since 35 ºC in 2015 on 11 December at 1:30 PM.
Lowest daily maximum temperature: 20.9 ºC on 12 December 2020 at 9:31 AM. This is the second lowest monthly and daily lowest daily maximum temperature for December on record and the lowest since the current record low of 18.9 ºC in 2011 on 7 December at 4:36 PM. Same month in 2019 was 26.6 ºC.
Highest daily minimum temperature: 26.2 ºC on 7 December 2020 at 4:28 AM. This is the highest daily minimum temperature on record for December exceeding the previous record high of 24.5 ºC in 2012 on 18 December 2020 at 4:00 AM. Same month in 2019 was 26.2 ºC.
Minimum temperatures in December were predominately above average during the month and were near or below average in the middle of the month and at the end of the month. The first 8 days of the month saw warm nights that peaked at 7 ºC above average on the 7th before temperatures between the 9th and 14th. Another period of warm nights followed on the 15th to 23rd of between 2 ºC to 4 ºC above average on the 18th to 20th. The remainder of the month was within 1 ºC of the average except for the 30th which was 5 ºC above average.
Maximum temperatures in December saw two periods of warm days at the start of the month and between the 18th and 23rd, as well as near average or below average temperatures. The 1st to 8th saw days that were peaked at 6 ºC above average on the 6th and was between 4 ºC and 6 ºC above average on the 4th to 7th. After near average temperatures, there were several cool to cold days on the 11th to 14th of between 4 ºC below average on the 14th and 9 ºC below average on the 12th. Further near average temperature followed before temperatures that were between 2 ºC and 4 ºC above average on the 20th to 23rd. During the remainder of the month temperatures were mostly 1 ºC to 4 ºC below average.
Monthly Mean Minimum Grass Temperature: 19.1 ºC (1.1 ºC higher than same month in 2019).
Lowest Minimum Grass Temperature: 13.8 ºC on 27 December 2020 (1.8 ºC higher than same month in 2019). This coincided with the lowest minimum air temperature of 16.6 ºC for the month.
Highest Minimum Grass Temperature: 21.9 ºC on 7 December 2020 (1.1 ºC lower than same month in 2019). This coincided with the highest minimum air temperature of 26.2 ºC for the month.
Highest Minimum Grass Temperature Depression: 4.3 ºC on 7 December 2020 with a minimum grass temperature of 21.9 ºC and an air temperature of 26.2 ºC.
Lowest Minimum Grass Temperature Depression: -2.4 ºC on 13 December 2020 with a minimum grass temperature of 20.5 ºC and an air temperature of 18.1 ºC.
Monthly mean daily minimum MSL pressure: 1010.2 hPa (0.3 hPa lower than same month in 2019).
Monthly mean daily maximum MSL pressure: 1015 hPa (0.7 hPa lower than same month in 2019).
Mean MSL pressure: 1012.6 hPa (0.7 hPa below average, 0.5 hPa lower than same month in 2019).
Lowest MSL pressure: 1004.1 hPa on 6 December 2020 at 4:33 PM. The same month in 2019 saw 1006.5 hPa. This is the highest monthly minimum air pressure for December since 1005.9 hPa in 2015 on 11 December at 4:40 PM
Highest MSL pressure: 1020.9 hPa on 12 December 2020 at 10:26 AM. The same month in 2019 saw 1030 hPa.
Monthly mean daily minimum relative humidity: 54.4 % (11.1 % higher than same month in 2019 and 3.5 % above average). This is the highest for December since 56.7 % in 2011.
Monthly mean daily maximum relative humidity: 92.5 % (6 % higher than same month in 2019 and 1.6 % above average).
Mean relative humidity: 73.4 % (8.5 % higher than same month in 2019 and 2.6 % above average). This is the highest for December since 75.6 % in 2011.
Lowest relative humidity: 19 % on 8 December 2020 at 3:49 PM (12 % higher than this month in 2019).
Highest relative humidity: 99 % on 15 December 2020 at 5:28 AM (2 % higher than this month in 2019).
Monthly mean daily minimum dew point: 17.8 ºC (1.3 ºC above average). This is the second highest monthly mean minimum dew point for December on record and the highest since the current record high of 19.1 ºC in 2010.
Monthly mean daily maximum dew point: 22.4 ºC (1.6 ºC above average). This is the highest mean maximum dew point for December on record exceeding the previous record high of 21.7 ºC in 2017.
Monthly mean dew point: 20.1 ºC (1.5 ºC above average). This is the second highest monthly mean dew point for December on record equalling 20.1 ºC in 2010.
Lowest dew point: 4.9 ºC on 8 December 2020 at 3:51 PM.
Highest dew point: 25.5 ºC on 17 December 2020 at 12:12 PM.
Highest wind gust: 50 km/hr on 14 December 2020 at 5:16 AM.
Highest wind speed: 21 km/hr on 7 December 2020 at 2:27 PM (Moderate Force Wind). This is the lowest monthly maximum wind speed for December on record, exceeding the previous record low of 25 km/hr in 2018 on 21 December at 5:45 PM.
Total Wind Run: 3720.2 km (743.2 km lower than same month in 2019), 418.1 km above average and 1.1 % above average.
Mean wind speed: 4.3 km/hr (1.7 km/hr lower than this month in 2019), 0.1 km/hr below the long term average).
Daily Mean Maximum Wind Gust: 28.1 km/hr (3.4 km/hr lower than this month in 2019), 0.9 km/hr above average and 3.9% above average. This is the lowest daily mean maximum wind gust on record for December and the lowest since 26.3 km/hr in 2014.
Daily Mean Maximum Wind Speed: 14.9 km/hr, 1.7 km/hr lower than this month in 2019), 3.7 km/hr above average and 4.4 % above average. This is the second lowest on record for December and lowest since the current record low of 14.7 km/hr in 2018.
Dominant Direction: NE (E this month last year).
Rainfall total: 145.9 mm, 16.7 mm above average (112.9 % of long term average), 57.1 mm below the long term median and 161 % of the site median. This total is higher than this month in 2019 which was 56 mm and is the highest since the current record high of 450.1 mm in 2010. Automatic rain gauge was 127.2 mm (-8.3 % of manual gauge).
Highest daily rainfall total: 70.1 mm on 14 December 2020. This is the highest on record for December since 82 mm in 1999 on 28 December.
Number of rain days: 12 days, 5 greater than same month in 2019 and 1.9 days below average.
The year to date total is 1135.5 mm (53 mm above average and 23.3 % above average) and compared with previous annual totals is the highest since 1263.6 mm in 2015.
Highest rainfall rate: 56.2 mm/hr on the 1 December 2020 at 3:48 PM. This is the lowest monthly rainfall rate for December on record since 55.2 mm/hr in 2012 on 10 December at 12:45 PM.
Highest hourly rainfall total: 13.2 mm on the 14 December 2020 at 12:32 AM.
Most rainfall in the month occurred between the 7th and 18th during an active period of drizzle, showers, rain, and mild thunderstorms. The first 8 days of the month was dry and later in the month there were some drizzle and light showers on some days. The highest daily total rainfall on the 14th was a result of light to moderate rain from the evening of the 13th to early on the 14th.
There were 0 days of morning dew.
Smoke haze on 1st to 4th, 6th, 7th and 9th.
An SSE to EESE wind change in the late afternoon of the 8th that brought cooler temperatures after a low intensity to severe intensity heatwave on the 1st to 7th.
In the early afternoon of the 23rd was an ESE to ENE wind change.
The minimum temperature was reached very early in the day on the 10th and 16th. The minimum temperature on the 14th was reached in the previous evening, whilst the recorded maximum temperature on the 14th occurred in the mid-morning after a cloudy and cold day on the 13th.
The heatwave at the start of the month and cloud cover during the middle of the day associated with the rainfall brought a significant number of warm nights during the month.
In the afternoon of the 7th the temperature dropped 7 ºC in just over an hour.
Light but gusty SSW to SW winds in the morning tended S to SE before dying down at midday. This was associated with the passage of a coastal low pressure system that brought severe weather over coastal areas that included heavy rainfall, though severe weather didn’t occur at this location.
Fog early in the day on the 15th with relative humidity near saturation.
In contrast to the previous month, high pressure systems extended ridges along the coastline that were not overly strong and allowed low pressure systems to bring more moisture into the region during the middle of the month. In the middle of the month a upper low pressure system moved northwards and a upper level trough induced a coastal trough to develop that brought an active period of instability and rainfall.
Most long period rainfall totals continue to remain below or well below average, that improved for many of these periods. 6 monthly rainfall improved a little to 18.3 mm below average, while 9 monthly rainfall deteriorated from 171.9 mm above average to 52.7 mm below average. 12 month rainfall improved by 91 mm to 94.2 mm above average and 18 month rainfall improved by 100 mm at 38 mm below average. 24 month to 48 month rainfall was between 156.7 mm below average for 48 month rainfall and 366.1 mm below average for 24 month rainfall. Compared with the same period in the previous year these periods improved, and the greatest improvement was 12 monthly rainfall that improved by 564 mm.
For December there were 3 existing records exceeded or equalled, along with 12 records that was highest/lowest in at least 5 years.
For more detailed analysis refer to the “Monthly Meteorological Report for December 2020”
Summary of Averages and Extremes for December 2020 for Ferny Grove, Brisbane, Queensland, Australia |
||||||||||||||||
|
Min Temp |
Max Temp |
Mean Temp |
Temp Range |
Min Grass Temp |
Min Grass Temp Depression |
Min Relative Humidity |
Max Relative Humidity |
Mean Relative Humidity |
Min MSL pressure |
Max MSL Pressure |
Mean MSL Pressure |
Dew Point |
Max Wind Gust |
Max Wind Speed |
Daily rain |
Average |
20.8 |
30.3 |
25.6 |
9.6 |
19.1 |
1.7 |
54.4 |
92.5 |
73.4 |
1010.2 |
1015.0 |
1012.6 |
20.1 |
28.1 |
14.9 |
4.7 |
Min |
16.6 |
20.9 |
18.8 |
2.6 |
13.8 |
-2.4 |
19 |
81 |
55 |
1004.1 |
1009.3 |
1006.8 |
4.9 |
19.0 |
9.0 |
|
Max |
26.2 |
35.9 |
30.7 |
14.9 |
21.9 |
4.3 |
88 |
99 |
94 |
1016.6 |
1020.9 |
1018.7 |
25.5 |
50.0 |
21.0 |
70.1 |
Total |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
145.9 |
Summary for December 2020 from long term average for Ferny Grove, Brisbane, Queensland, Australia |
||||||||
|
Temperature |
Relative Humidity |
MSL Pressure |
Dew Point |
Wind Gust |
Wind Speed |
Rainfall |
Rainfall as Fraction of monthly average (%) |
Average |
+1.0 |
+2.6 |
-0.8 |
+1.5 |
+3.9 |
+4.4 |
+16.7 |
112.9 |
Min |
+1.6 |
+3.5 |
|
+1.3 |
|
|
|
|
Max |
+0.3 |
+1.6 |
|
+1.6 |
|
|
+104.1 |
|
Monthly averages and extremes for Year of 2020 to Date for Ferny Grove, Brisbane, Queensland, Australia |
|||||||||||
|
Temperature |
Temperature Anomaly from Long Term Avg. |
Rain total |
Rain Anomaly |
Rain days |
||||||
|
Avg Min |
Avg Max |
Low Min |
High Max |
Average |
Min |
Max |
Average |
|
|
|
Jan-20 |
21.9 |
32.2 |
18.6 |
35.4 |
27.0 |
+1.2 |
+1.5 |
+1.4 |
183.3 |
+38.3 |
15 |
Feb-20 |
21.2 |
30.4 |
19.6 |
37.6 |
25.8 |
+0.9 |
+0.4 |
+0.7 |
389.2 |
+227.4 |
20 |
Mar-20 |
18.7 |
29.1 |
15.1 |
35.2 |
23.9 |
-0.5 |
+0.4 |
-0.0 |
142.4 |
+18.2 |
15 |
Apr-20 |
16.0 |
29.1 |
11.9 |
34.2 |
22.6 |
+0.0 |
+2.7 |
+1.4 |
13.5 |
-80.3 |
9 |
May-20 |
12.7 |
24.2 |
9.1 |
28.1 |
18.4 |
+0.2 |
+0.0 |
+0.6 |
12.1 |
-90.9 |
8 |
Jun-20 |
11.0 |
22.6 |
5.9 |
25.8 |
16.8 |
+0.5 |
+1.1 |
+0.9 |
45.5 |
-16.4 |
13 |
Jul-20 |
10.0 |
22.2 |
5.0 |
26.1 |
16.1 |
+1.1 |
+0.4 |
+1.2 |
50.4 |
+16.9 |
8 |
Aug-20 |
10.1 |
24.0 |
4.2 |
27.9 |
17.0 |
+1.1 |
+1.2 |
+1.2 |
14.8 |
-21.7 |
3 |
Sep-20 |
13.3 |
25.9 |
8.0 |
32.6 |
19.6 |
+1.3 |
+0.5 |
+0.9 |
14.2 |
-19.0 |
3 |
Oct-20 |
15.0 |
27.8 |
11.6 |
32.6 |
21.4 |
+0.4 |
+1.0 |
+0.8 |
119.5 |
+55.0 |
12 |
Nov-20 |
17.0 |
29.7 |
12.8 |
35.3 |
23.4 |
-0.5 |
+0.4 |
-0.1 |
4.7 |
-91.2 |
4 |
Dec-20 |
20.8 |
30.3 |
4.2 |
35.9 |
25.6 |
+1.6 |
+0.3 |
+1.0 |
145.9 |
+16.7 |
12 |
YTD |
15.6 |
27.3 |
4.2 |
37.6 |
21.5 |
+0.6 |
+0.8 |
+0.8 |
1135.5 |
+53.0 |
122 |
Based on Bureau of Meteorology Climate summaries (Copyright) of which some data was obtained from. From September 2017 the Bureau of Meteorology Climate summaries were expanded to provide data from official stations in and near the Greater Brisbane “Greater capital city Statistical Area” (GCCSA).
Data Copyright Ferny Grove Weather 2020, Produced 31/01/21. Data Checking has been carried out but errors may still be present and therefore there is no assurance of correctness. Corrections may be made at a later data if errors or deficiencies are found and/or improvements in data handling techniques are made, though data with major improvements may not be updated in this summary. Data measured with professional moderate accuracy equipment. This replaced non professional equipment of low accuracy with differences in the measured data. The new equipment measures the daily average wind speed and wind run about 40 % higher. Daily rainfall and grass minimum temperature is measured using non-professional equipment of moderate accuracy.
Site Commencement data is April 15 2009 except for daily rainfall which commenced on January 1 1987. Not all variables have been measured over the entire station record. Most variables are measured over a 24 hour period ending in the evening and over a 24 hour period from midnight effective October 5 2018. Maximum temperatures are measured over the 24 hours from 9 am on the day of measurement. Minimum temperatures are measured over the 24 hours to 9 am of the day of measurement. Rainfall is measured over 24 hours to 9am and recorded on that day. This is the same as the official time standard. Some rainfall measurements are not made at 9am and is adjusted based on the automatic record. Minimum Grass Temperature is measured over an approx. 12 hour period ending in the early morning. MSL refers to Mean Sea Level, which is the standard meteorological method of measuring air pressure reduced to sea level based on both elevation and temperature. Grass Minimum Depression is the difference of the grass minimum temperature from the air temperatures and is a positive value when the grass temperature is below the air temperature.
Up until March 9 2019 automatic records as Dew Point, Average Wind Speed, Dominant Wind Direction, Wind Run, Rain Rate and Hourly Rain are measured over a 24 hour period starting at midnight and recorded for that day. This started on the 6 October 2011. The automatic record is used for some data and also may be used if data is not available/ not suitable. From March 9 2019 the automatic record became the official record instead, simplifying this process. Until replaced on 5 October 2018 the temperature and humidity sensor is under exposed so minimum temperature and maximum humidity are incorrect and low accuracy rain gauge is used which are not used as the site’s official record. This data limitation does not apply to other measurements of temperatures, air pressure and humidity, wind gust, daily and monthly rainfall and rain days elsewhere in this summary which are recorded separately and form the official record for this site. The replacement equipment is sited in more exposed locations and therefore the limitations don’t apply, though the automatic daily rainfall doesn’t form the official data for the site.
Long term averages are based on all available long period past measurements from October 2019 whilst for non automatic rainfall is based on 1987 to 2017 average from the station record, while. Prior to this the long term average for Temperature, Relative Humidity and Air pressure is based on 2009 to 2015 average from the station record and wind speed is based on the 2010 to 2018 average from station record. Wind Run is 2011 to 2018 and Rain Rate and High Hourly Rain is 2011 to 2017.
The Fraction of monthly average expresses how much has fallen in respect to the long term average listed as a percentage. The decile ranking compares the rainfall total to the historical record for the site where the record is divided into 10 equal groups. Decile 1 is the lowest 10% of the record (10th percentile) and Decile 10 (90th percentile) is the highest 10% of the record. Decile 1 is considered “very low”, decile 2 and 3 “low”, decile 4 to 7 “average”, decile 8 and 9 “high” and decile 10 “very high”.