December Summary

Below average temperature, 127% of expected rainfall.

(December compared to my records from the past 10 years.)

  • This December was below my average temperature of 16.5C with 15.9C
    • The coldest temperature was 3.6C, lower than my average minimum of 5.1C.
    • Twenty Three days reached or exceeded 20C, my average is 21.
    • Thirteen days reached or exceeded 25C, my average is 9.
    • Two days reached or exceeded 30C, my average is 2.
    • One day reached or exceeded 35C, my average is 0 though 2017 and 2010 had 1 December day that also reached or exceeded 35C.
  • Wind run was 95% of my average of 5388km with 5103km.
  • The barometer recorded average pressure for the month with 1010.8hPa. My average is 1010.9hPa.
  • Rainfall was 127% of the average expected total of 48mm with 61mm,
    • The driest December in the past 10 years is 2014 which had 26mm.
    • The wettest December in the past 10 years is 2013 with 70.5mm.
    • The driest December in my records is 2003 with just 2mm.
    • 2020 was 261mm below the expected average rainfall for the year.
December 2020 Summary
Temperature
Mean 15.9 C
Mean Maximum 23.4 C
Mean Minimum 10.3 C
Maximum High 35.2 C (19th)
Maximum Low 15.7 C (8th)
Minimum High 15.8 C (21st)
Minimum Low 3.6 C (28th)
Wind Speed and Direction
Maximum Gust 66 km/h (11th)
Mean 7.2 km/h
Wind Run 5103 km
Max Daily Windrun 254 km (7th)
Prevailing Direction East North East
Barometer
Maximum 1027.8 hPa (14th)
Minimum 987.2 hPa (24th)
Mean 1010.8 hPa
Max Daily Change -20.6 hPa (2nd)
Rainfall
Days with Measured Rainfall
(0.2mm or more)
10
Max Daily Rainfall 18.0 mm (27th)
Monthly Rainfall 61.0 mm
Humidity
Maximum 95 % (22nd)
Minimum 23 % (3rd)

 

December Daily Observations
TemperatureWindRainfallBarometer
DateMinMaxMeanMean
(Km/h)
Gust
(Km/h)
Run (km)Prevailing Dir10 Minute Max (mm)Total (mm)Min (hPa)Max (hPa)Change (hPa)
1 8.4 22.2 13.2 9.3 38 212 South Sth West 0 0 1009.2 1019.5 +10.3
Few spots of rain in the morning. Cloud breaking to a mostly sunny afternoon with southerly winds turning NE.
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2 10.3 27.0 16.7 10.3 57 234 East Nth East 0 0 998.4 1019.0 -20.6
Overcast in the morning. Cloud breaking during the afternoon with gusty warm northerly winds in the evening.
3 8.6 27.9 17.2 7.9 37 181 East Nth East 0 0 997.3 1007.7 +10.4
Few clouds, light north to NW winds in the morning turning fresh cooler NE in the afternoon.
4 6.5 26.6 16.1 5.2 39 112 North Nth West 0 0 1000.2 1007.8 -7.6
Morning cloud breaking to a sunny afternoon with warm northerly winds.
5 7.9 25.4 15.3 6.0 45 136 East Nth East 2.8 4.0 992.7 1004.3 +11.6
Variable cloud, a few spots of rain early afternoon. Evening thunderstorm with a brief heavy shower and southerly winds.
6 6.7 19.9 12.9 7.5 38 172 East Nth East 0 0 998.8 1008.6 -9.8
Cloud increasing from morning with NE winds freshening in the afternoon.
7 14.3 30.9 22.9 11.2 43 254 North Nth West 0 0 993.2 1000.7 +7.5
Sunny fir much of the day with warm northerly winds. Overcast with high cloud later in the afternoon.
8 15.7 29.3 21.8 8.3 50 190 North Nrh West 0 0 995.7 1003.3 +7.5
Overcast with high cloud and warm northerly winds.
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9 12.1 26.3 18.0 5.0 27 113 East Nth East 0 0 1002.4 1006.7 -4.3
Morning cloud breaking, mostly sunny in the afternoon,  NE wind.
10 12.9 25.4 17.2 8.1 30 184 East Nth East 0 0 1002.0 1005.1 -3.1
Morning cloud breaking and clearing in the afternoon. West to SW wind turning NE mid afternoon.
11 10.1 24.9 15.7 9.1 66 209 South Sth West 0 0 997.2 1005.1 +7.9
Morning northerly winds turning strong southerly in the afternoon with cloud but remaining dry. Cloud clearing and winds easing later in the afternoon. Maximum temperature recorded at 9:30am.
12 8.3 23.8 14.8 7.0 34 159 South Sth West 0 0 1004.8 1014.7 +9.9
Morning cloud breaking so a sunny day with light southerly winds turning fresher NE in the afternoon.
13 7.4 18.9 13.3 7.1 39 163 South Sth West 0 0 1015.0 1025.8 +10.8
Partly cloudy, cool southerly wind.
14 9.2 23.7 15.1 3.1 21 90 East Nth East 0 0 1025.2 1027.8 +2.6
Morning cloud clearing to a sunny and mild afternoon with light southerly winds turning NE.
15 8.7 25.5 17.8 6.7 32 154 East Nth East 0 0 1015.5 1027.5 -12.0
Morning cloud clearing to a sunny day with a NE wind.
16 11.8 27.1 17.6 9.7 33 222 West 0 0 1013.2 1016.3 -3.1
Low cloud and mist in the morning clearing. High cloud increasing during the afternoon with winds turning NE.
17 12.4 20.4 14.9 6.6 29 150 East Nth East 0 0 1015.1 1023.4 +8.3
Overcast with drizzle at times, NE wind.
18 12.3 21.8 16.6 10.8 42 246 East Nth East 0 0 1010.0 1022.5 -12.5
Drizzle clearing by dawn. Cloud breaking by late morning to a sunny afternoon with a fresh NE wind.
19 11.5 35.2 22.6 3.9 32 89 north Nth West 0 0 1006.6 1010.5 -3.9
Sunny morning, high cloud increasing from midday, mostly light warm northerly winds.
20 12.2 19.8 16.8 7.6 37 134 South Sth West 0.4 1.4 1009.3 1022.8 +13.3
Cloudy with southerly winds. Winds easing later in the afternoon with a few spots of rain. Showers in the evening.
21 11.7 15.8 13.4 7.5 34 172 East Nth East 1.2 7.6 1012.0 1022.9 -10.9
Overcast with showers and a period of rain from late morning, clearing in the afternoon. NE wind.
22 14.0 26.1 18.4 6.8 31 153 East Nth East 0.4 2.4 1005.4 1011.8 -6.4
Light morning rain. Cloud breaking to a warm and sunny afternoon. NE wind.
23 13.8 25.5 17.4 3.2 26 74 East Nth East 0.4 5.2 990.9 1006.8 -15.9
Cloudy with a few spots of rain around midday. Showers from evening. Light NE wind.
24 13.2 21.5 16.7 5.0 28 113 South Sth West 0.4 3.6 987.2 999.8 +12.6
Variable cloud with some showers and sunny intervals. Light winds tending southerly.
25 10.5 18.3 13.0 5.6 28 126 East Nth East 0.8 5.0 999.8 1008.4 +8.6
Overcast, light rain in the morning. Sunny intervals after midday but cloud thickening with showers later in the afternoon.
26 8.5 16.5 11.7 8.7 34 198 South Sth West 2.6 8.2 1007.0 1019.4 +12.4
Morning showers clearing with a few sunny intervals in the afternoon. Showers returning in the evening.
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27 6.4 17.0 10.5 6.8 31 154 South Sth West 1.6 17.8 1019.2 1024.2 +5.0
Morning rain clearing around midday with cloud breaking. Cold southerly wind.
28 3.6 21.0 12.4 3.9 25 88 East Nth East 0 0 1017.4 1024.2 -6.8
Sunny and mild from late morning, light W to SW winds turning NE in the afternoon.
Christchurch water use getting closer to restriction levels
29 4.6 19.7 13.1 6.2 33 142 East Nth East 0 0 1017.8 1019.2 +1.4
Sunny and mild. Cool NE wind freshening later in the afternoon.
30 12.1 20.1 14.7 9.0 32 205 Eat Nth East 0 0 1017.8 1026.0 -8.2
Overcast but a few sunny intervals in the afternoon. NE wind.
Recent rain provides little relief for Christchurch's dry Port Hills
31 13.3 20.6 15.9 9.3 36 213 East Nth East 0 0 1018.6 1026.6 -7.4
Mostly cloudy but a few sunny intervals. NE wind.


December 2020  Temperature Graph
December 2020 Wind Dir Graph
December 2020 Wind Dir Graph
December 2020 Wind Speed Graph
December 2020 Rainfall Graph
December 2020 Barograph
December 2020 Humidity Graph