My September
Temperature: A mean temperature of 9.7C, this September was just above my September mean of 9.6C. The warmest day was the 29th with 23.2C with warm west to nor'west winds. The warmest September temperature I've recorded was 24.0C in 2001 with nor'west winds. Coldest temperature was-3.1C with a frost on the 6th, equaling the coldest September temperature I recorded on 12th Sept 2000. (Note: old temperature sensor in operation in 2000, reading low)
Wind: The monthly wind run of 4625km is close to the average of 4844km (8 Septembers records). The windiest September was 2003 with a wind run of 5356km. Prevailing wind direction was north east recorded 35% of the month, south 27%, north 15%, south west and west 10%, north and nor'west 8%, and south east 2%. Maximum gust was 49km/h from the south on the 2nd.
Rainfall: The monthly total was 45.8mm, a little less then the monthly average of 52mm (8 years records). Maximum daily rainfall was 19.6mm on the 4th with a cold southerly change in the morning with rain and strong winds for a time. A few snow flakes reported in Christchurch but nothing settling. Further heavy showers with hail in the evening. The highest September total from 2000 at my station is 101mm in 2000 and the highest daily total is 48.8mm from melting snow on the 19th Sept 2005. The lowest monthly total was just 5mm in 2006.
Barometer: The highest pressure for the month was recorded on the 5th with 1040.3 hPa, the lowest 997.3 hPa on the 30th. The mean pressure for the month of 1015.5 hPa, Sept 2006 mean pressure was 1014.0hPa, the only other year for comparison. Humidity: Lowest humidity was 25% on the 29th with wind from the nor'west. The highest humidity was 98% on the 24th with a southerly wind and showers.
| September 2007 Summary Temperature |
|
|---|---|
| Mean | 9.7C |
| Mean Maximum | 15.2C |
| Mean Minimum | 5.0C |
| Maximum High | 23.2C (29th) |
| Maximum Low | 13.7C (30th) |
| Minimum High | 8.9C (5th) |
| Minimum Low | -3.1C (6th) |
| Wind Speed and Direction | |
| Maximum Gust | 49 km/h (2nd) |
| Mean | 6.5 km/h |
| Wind Run | 4625 km |
| Max Daily Windrun | 277 km (23rd) |
| Prevailing Direction | North East |
| Barometer | |
| Maximum | 1040.3 hPa (5th) |
| Minimum | 997.3 hPa (11th) |
| Mean | 1015.5 hPa |
| Max Daily Change | +22.1 hPa (12th) |
| Rainfall | |
| Days with Measured Rainfall (Greater than 0.2mm) | 7 |
| Max Daily Rainfall | 19.6 mm (4th) |
| Monthly Rainfall | 45.8 mm |
| Humidity | |
| Maximum | 98 % (24th) |
| Minimum | 25 % (29th) |
| September Daily Observations | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | 7.4 | 20.5 | 13.9 | 6.6 | 41 | 157 | North West | 0 | 0 | 1003.6 | 1014.6 | -11.0 |
| High cloud in the morning, mostly sunny in the afternoon. Gusty nor'westerly winds at times, easing in the afternoon. | ||||||||||||
| 2 | 7.3 | 17.8 | 11.0 | 10.5 | 49 | 247 | North East | 0 | 0 | 1003.5 | 1020.1 | +16.6 |
| Strong southerly winds for a time in the morning easing and turning NE. Some high cloud in the afternoon. | ||||||||||||
| 3 | 6.6 | 15.1 | 11.1 | 4.5 | 32 | 107 | North | 0 | 0 | 1006.0 | 1016.3 | -10.3 |
| Overcast with high cloud. North the NE winds. | ||||||||||||
| 4 | 2.9 | 11.1 | 6.7 | 9.3 | 44 | 218 | South | 1.6 | 19.6 | 1005.6 | 1027.7 | +22.1 |
| Cold southerly change in the morning with rain and strong winds for a time. Minimum temperature recorded at 11:40am. A few snow flakes reported in Christchurch but nothing settling. Further heavy showers with hail in the evening. | ||||||||||||
| 5 | -0.9 | 8.9 | 4.3 | 9.0 | 45 | 214 | South | 0.8 | 9.6 | 1028.2 | 1040.3 | +12.1 |
| Overcast and cold with showers in the morning. Cloud clearing to a mostly sunny afternoon with light cold southerly winds. Frosty at night. | ||||||||||||
| 6 | -3.1 | 10.9 | 3.6 | 2.0 | 21 | 47 | North East | 0.2 | 0.2 | 1032.1 | 1040.1 | -8.0 |
| Frost then sunny with light NE breeze. 0.2mm from frost condensation. | ||||||||||||
| 7 | 0.0 | 12.0 | 5.7 | 6.0 | 34 | 142 | North East | 0 | 0 | 1019.0 | 1031.9 | -12.9 |
| Frost, clear and sunny with NE winds. | ||||||||||||
| 8 | 0.0 | 16.3 | 7.9 | 3.0 | 21 | 71 | North East | 0 | 0 | 1014.6 | 1019.1 | -4.5 |
| Frost. Clear and sunny with light NE winds in the afternoon. | ||||||||||||
| 9 | 1.5 | 12.4 | 7.0 | 4.5 | 26 | 105 | North East | 0 | 0 | 1011.7 | 1018.9 | -7.2 |
| Cloud increasing in the morning to be quite thick by midday but clearing in the afternoon. Cool NE winds. | ||||||||||||
| 10 | 2.7 | 13.5 | 7.5 | 1.8 | 20 | 42 | North East | 0 | 0 | 1006.4 | 1011.5 | -5.1 |
| Broken cloud with some sunny intervals. Light NE winds. | ||||||||||||
| 11 | 0.5 | 14.5 | 7.4 | 4.1 | 22 | 95 | North East | 0 | 0 | 1008.4 | 1015.7 | +7.3 |
| Mostly clear and sunny with high cloud increasing in the afternoon | ||||||||||||
| 12 | 1.6 | 17.3 | 8.9 | 2.9 | 21 | 68 | North East | 0 | 0 | 1015.8 | 1020.8 | +5.0 |
| Sunny with some high cloud, light NE winds. | ||||||||||||
| 13 | 1.2 | 19.1 | 11.1 | 4.1 | 29 | 97 | North | 0 | 0 | 1011.9 | 1019.7 | -7.8 |
| Light frost, sunny and mild with light northerly winds. High cloud increasing during the afternoon. | ||||||||||||
| 14 | 8.8 | 20.3 | 13.3 | 4.0 | 25 | 94 | South | 0.2 | 0.4 | 1004.7 | 1020.9 | +11.2 |
| Mostly cloudy but some breaks with a bit of sun. Light showers from late afternoon. | ||||||||||||
| 15 | 8.9 | 13.6 | 10.5 | 8.7 | 40 | 206 | North East | 0 | 0 | 1009.2 | 1021.5 | -12.3 |
| Broken cloud with a fresh cool NE wind. | ||||||||||||
| 16 | 8.0 | 22.2 | 14.9 | 6.9 | 44 | 164 | North East | 0 | 0 | 1002.4 | 1009.0 | -6.6 |
| Morning high cloud clearing to a sunny day with mild north to nor'west winds gusty at times. | ||||||||||||
| 17 | 6.6 | 18.2 | 11.0 | 6.1 | 25 | 145 | South | 0 | 0 | 1006.3 | 1017.0 | +10.7 |
| Sunny with some high cloud from afternoon. Southerly winds turning NE in the evening. | ||||||||||||
| 18 | 5.9 | 12.0 | 9.2 | 4.6 | 26 | 109 | North East | 0 | 0 | 1016.9 | 1020.0 | +3.1 |
| Overcast with cool north east winds. | ||||||||||||
| 19 | 8.8 | 13.2 | 10.4 | 5.5 | 27 | 129 | North East | 0.2 | 2.6 | 1016.6 | 1020.4 | +3.8 |
| Overcast with light morning showers. Cool NE winds. | ||||||||||||
| 20 | 8.0 | 14.4 | 11.4 | 8.9 | 43 | 210 | North East | 0 | 0 | 1014.7 | 1020.7 | -6.0 |
| Broken cloud with a fresh cool NE wind. | ||||||||||||
| 21 | 8.1 | 16.3 | 11.1 | 4.4 | 20 | 104 | North East | 0 | 0 | 1009.5 | 1014.7 | -5.2 |
| Misty low cloud lifting and clearing for a time but returning later in the afternoon. Light southerly winds for much of the day, turning NE later in the afternoon with the return of low cloud and mist. | ||||||||||||
| 22 | 7.5 | 16.4 | 11.3 | 5.4 | 25 | 128 | North East | 0 | 0 | 999.8 | 1009.5 | -9.7 |
| Low morning cloud lifting with broken high cloud in the afternoon. Mild northerly winds for a time in the afternoon. | ||||||||||||
| 23 | 7.3 | 11.9 | 9.3 | 11.7 | 34 | 277 | South | 0.4 | 9.6 | 1001.8 | 1011.5 | +9.7 |
| Overcast with low cloud. Light rain from morning, cool southerly winds. | ||||||||||||
| 24 | 7.2 | 13.1 | 8.9 | 7.5 | 22 | 179 | South | 0.2 | 2.4 | 1009.3 | 1011.8 | +2.5 |
| Morning light showers clearing but remaining cloudy with a cool southerly wind. | ||||||||||||
| 25 | 6.6 | 13.2 | 8.7 | 10.4 | 35 | 244 | South | 0 | 0 | 1010.6 | 1016.5 | +5.9 |
| Broken cloud for much of the day with sunny intervals. Cloud increasing in the afternoon with a few spots of rain. Cool southerly winds. | ||||||||||||
| 26 | 3.6 | 9.1 | 6.7 | 9.0 | 34 | 213 | South | 0.4 | 1.0 | 1016.6 | 1023.1 | +6.5 |
| Early showers clearing and cloud breaking in the afternoon. Cold southerly winds | ||||||||||||
| 27 | 4.4 | 13.0 | 8.1 | 7.0 | 25 | 166 | North East | 0.2 | 0.2 | 1022.6 | 1026.0 | +3.4 |
| Showers clearing by dawn and cloud breaking and mostly clearing by midday. Southerly winds turning NE late afternoon. | ||||||||||||
| 28 | 5.8 | 13.9 | 10.0 | 11.6 | 39 | 274 | North East | 0 | 0 | 1018.2 | 1024.4 | -6.2 |
| Sunny with a little high cloud in the afternoon. Fresh NE winds. | ||||||||||||
| 29 | 3.5 | 23.2 | 13.7 | 5.1 | 34 | 120 | North | 0 | 0 | 1009.4 | 1018.0 | -8.6 |
| Sunny morning but high cloud increasing in the afternoon and becoming overcast. Mild northerly winds. | ||||||||||||
| 30 | 13.7 | 21.8 | 16.5 | 10.5 | 34 | 237 | North East | 0 | 0 | 997.3 | 1009.1 | -11.8 |
| Overcast in the morning, cloud breaking from afternoon. Mild northerly winds. | ||||||||||||
