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 | ||||||||||||
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Temperature | Wind | Rainfall | Barometer | |||||||||
Date | Min | Max | Mean | Mean (Km/h) | Gust (Km/h) | Run (km) | Prevailing Dir | 10 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 |
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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. Winter weather: 2020 was New Zealand's warmest on record, fuelled by climate change - Niwa Warmest winter on record a 'dress rehearsal' for winters to come |
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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 |
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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. NZ's warming seas: Is another 'marine heatwave' coming? |
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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. Why NZ could be in for another unusually hot summer |
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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 |
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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 |
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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 |
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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. Warm and wild: Three ways La Niña will mess with our summer |