September Summary

Above average temperature, near average wind run and 54% of expected rainfall.
This September set 2 records for maximum and minimum temperature.

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

  • This September was just above my average temperature of 9.8C with 10.3C.
    • The warmest temperature was 27.1C, my highest September temperature in the past 10 years and also my 20 years records
    • The coldest temperature was -3.6C, my lowest September temperature in the past 10 years and also my 20 years records
    • Seven days recorded an air frost (0c or below), my average is 2 days.
    • This is the highest number of September air frosts in the past 10 years. 2000 is the only other September to record 7 air frosts.
    • No days failed to reach 10C, my average is 1.
    • Nineteen days reached or exceeded 15C, my average is 16.
    • Ten days reached or exceeded 20C, my average is 16.
    • 1 day reached or exceeded 25C, my average is 0.
  • Wind run was 95% of my average of 4560km with 4332km.
  • The barometer recorded above average pressure for the month with 1011.3hPa. My average is 1009.5hPa.
  • Rainfall was 54% of the average expected total of 44mm with 23.5mm, the driest September in the past 10 years.
    • The wettest September in the past 10 years is 2015 with 70.5mm.
    • 2020 is now 246mm below the expected average rainfall total as at 30 Sept.
September 2020 Summary
Temperature
Mean 10.3 C
Mean Maximum 17.8 C
Mean Minimum 3.2 C
Maximum High 27.1 C (23rd)
Maximum Low 10.2 C (23rd)
Minimum High 10.4 C (29th)
Minimum Low -3.6 C (30th)
Wind Speed and Direction
Maximum Gust 63 km/h (17th)
Mean 6.3 km/h
Wind Run 4332 km
Max Daily Windrun 304 km (17th)
Prevailing Direction East North East
Barometer
Maximum 1035.2 hPa (7th)
Minimum 975.7 hPa (27th)
Mean 1011.3 hPa
Max Daily Change +21.0 hPa (1st)
Rainfall
Days with Measured Rainfall
(0.2mm or more)
8
Max Daily Rainfall 6.6 mm (1st)
Monthly Rainfall 23.8 mm
Humidity
Maximum 95 % (9th)
Minimum 27 % (27th)

 

September 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 3.4 14.0 6.7 8.7 51 199 West 0.8 6.6 993.2 1015.2 +22.0
Early cold southerly change with showers. Snow to low levels in parts of Canterbury and Otago. Maximum temperature recorded at 4am, Minimum temperature recorded at 9:30am.
'Bitterly cold' day for South Island with widespread snowfall on first day of spring
2 -0.6 11.0 5.2 2.4 15 54 West 0 0 1015.5 1023.4 +7.9
Some cloud but mostly sunny with light winds tending westerly.
3 -3.1 14.6 5.9 3.3 22 76 East Nth East 0 0 1023.5 1027.8 +4.3
Morning frost. Sunny with light northerly winds turning NE in the afternoon.
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4 6.0 18.3 10.5 5.9 27 133 East Nth East 0 0 1010.0 1024.7 -14.7
Sunny morning. Overcast with high cloud about midday, cloud breaking in the afternoon. NE wind.
5 5.8 19.1 11.9 3.6 22 81 East Nth East 0 0 1009.3 1013.4 +4.1
Cloud with sunny intervals, light NE winds. Mild in the afternoon.
6 7.9 19.6 12.0 4.0 34 91 East Nth East 0.2 0.6 1007.3 1024.0 +16.7
Morning cloud breaking to a sunny and mild afternoon with light winds. Cloud increasing with rumble of thunder and light showers later in the afternoon.
North Canterbury town pounded by 'unbelievable' hail storm
7 4.1 14.6 8.9 4.1 26 93 South Sth West 0.2 0.2 1024.3 1035.2 +10.9
Showers clearing before dawn. Morning cloud breaking to a mostly sunny afternoon with light southerly winds.
8 6.2 14.6 9.6 8.7 33 199 East Nth East 0 0 1021.4 1035.0 -13.6
Sunny with NE wind.
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9 1.5 23.4 11.6 3.0 30 68 West Nth West 0 0 1008.9 1021.0 -12.1
Morning fog clearing to a sunny and mild day. High cloud increasing from afternoon. Light winds tending WNW in the afternoon.
10 3.2 11.8 8.3 3.7 24 85 South Sth West 0.4 6.4 1009.2 1017.5 +8.3
Morning rain clearing in the afternoon with sunny intervals. Showers returning in the evening, light southerly winds.
11 0.0 10.5 6.1 7.5 35 172 South Sth West 1.0 6.0 1017.6 1032.1 +14.5
Morning showers clearing in the afternoon with cloud breaking. Cool southerly wind.
12 -0.4 12.6 6.5 6.2 29 140 East Nth East 0 0 1021.3 1031.6 -10.3
Sunny morning, cloud increasing in the afternoon, cool NE wind.
13 1.7 18.1 9.3 1.1 30 26 East Nth East 0 0 1013.2 1021.2 -8.0
Mostly cloudy with high cloud, light winds with mild northerlies in the afternoon.
14 4.5 22.4 13.9 7.3 51 165 North Nth West 0 0 998.4 1013.1 -14.7
Some high cloud but mostly sunny with mild northerly winds.
15 3.9 15.1 11.0 10.7 51 244 North Nth West 0 0 995.1 1003.1 +8.0
Variable high cloud with sunny intervals and cool nor'west winds.
16 -0.6 18.9 10.3 7.7 53 175 North Nth West 0 0 1003.7 1012.3 +8.6
Morning frost. Sunny with mild nor'west winds from later in the morning.
17 5.8 23.7 15.0 13.3 63 304 North Nth West 0.2 0.6 1001.3 1011.3 +10.0
Sunny morning with mild, gusty nor'west winds. Cloud increasing in the afternoon with a southerly change in the evening and light rain.
18 2.9 17.0 9.1 4.2 40 95 North Nth West 0.2 3.0 1007.4 1014.1 -6.7
Early rain clearing by dawn, cloud clearing to a sunny day with light nor'west breezes.
19 1.5 17.9 9.2 2.0 22 45 South Sth West 0 0 1012.7 1028.3 +15.6
Sunny with a few clouds, light southerly breezes.
20 6.0 14.9 10.2 8.8 36 200 East Nth East 0 0 1025.1 1028.4 -3.3
Sunny with NE wind.
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21 2.6 20.5 10.9 2.5 24 56 East Nth East 0 0 1016.5 1025.2 -8.7
Morning fog and mist clearing to a sunny day with light NE winds.
22 0.8 23.8 13.2 4.9 35 111 North Nth West 0 0 1001.5 1016.3 -14.8
Light morning frost. Variable high cloud, NE wind turning mild northerly in the afternoon.
23 10.2 27.1 17.9 6.7 28 152 East Nth East 0 0 994.5 1001.6 -7.1
Sunny and warm with NE winds turning warm northerly from late morning. 
Spring temperatures hit mid-20s in Canterbury, while West Coast gets a deluge
24 7.8 22.9 15.2 9.6 37 219 North Nth West 0 0 996.8 1000.6 -3.8
Morning fog clearing to a sunny day with now'west winds from late morning
Big weekend storm threat for whole country, transport disruption likely as deepest low 'for a long time' races past
25 6.2 21.2 13.9 5.2 27 118 East Nth East 0 0 998.7 1009.3 +10.6
Sunny with variable winds tending NE.
26 5.4 22.5 14.4 8.6 34 196 East Nth East 0 0 988.4 1009.5 -21.1
Sunny morning. Cloud increasing in the afternoon, mild with north to NE winds.
27 6.4 22.3 14.2 13.7 55 299 North Nth East 0 0 975.7 988.6 -12.9
Few brief morning showers then sunny with north to NE winds with a cooler southerly change in the afternoon before winds swing back to nor'west.
28 1.4 15.1 7.7 9.4 59 214 North Nth West 0.2 0.4 981.3 990.5 +9.2
Nor'west winds with a period of rain around midday. A cold southerly change late afternoon with a few spots of rain.
In Pictures: 'Weather bomb' hits South Island, causing heavy snowfall
29 -1.5 10.4 4.6 10.1 56 230 South Sth West 0 0 989.4 1007.7 +18.3
Morning frost. Sunny with a very cold southerly wind from mid morning.
30 -3.6 14.7 6.6 3.4 29 76 South Sth West 0 0 1007.9 1021.5 +13.6
Morning frost. Sunny with mostly light southerly wind dying away later in the afternoon.
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September 2020  Temperature Graph
September 2020 Wind Dir Graph
September 2020 Wind Dir Graph
September 2020 Wind Speed Graph
September 2020 Rainfall Graph
September 2020 Barograph
September 2020 Humidity Graph