December 2005
Overview
Like November, December 2005 was another month of below-average temperature in Canterbury. The mean temperature for the month was just 4.6C, some 0.7C below the estimated long-term average. There were a total of 11 days with air frosts (about 3 days more than usual). Of note was the 29th which saw the lowest temperature of the month (-4.7C) and also the lowest daytime maximum of the year (0.3C). The temperature rose to 2.1C during the early hours of the 30th. Rainfall was again below average with 55.4mm (71%) being recorded. Nearly half of the rainfall total was made up of snowfall between the 26th and 30th. Around 2cm of snow was lying at 9am on the 27th, 8cm at 9am on the 28th, 7cm at 9am on the 29th and 5cm at 9am on the 30th. A further 3cm fell during the day of the 30th before turning to rain and a thaw setting in. About 50% coverage remained at 9am on the 31st and traces survived until the evening of the 1st January. The total rainfall for 2005 was 486.9mm (240.6mm less than or 67% of the local average of 727.5mm). Only 1 month in the last 16 (July 2005) has exceeded the local average for rainfall. Large variations in pressure were recorded - 979.3mb on the 2nd was the lowest recorded pressure of 2005; 1039.8mb on the 10th was the highest recorded pressure of 2005.
Temperature
| Absolute Maximum | 11.8 °C | 16th |
| Mean Maximum | 7.6 °C (-0.4°C) | |
| Mean (integration) | 4.6 °C | |
| Mean ((max+min)/2) | 4.6 °C (-0.7°C) | |
| Mean Mininum | 1.6 °C (-1.0°C) | |
| Absolute Minimum | -4.7 °C | 29th |
| Air Frosts | 11 (+2.9) | |
Temperature Distribution
| Maxima (°C, days) |
|---|
| < -5 | -5 - 0 | 0 - 5 | 5 - 10 | 10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | > 30 |
| 0 | 0 | 4 | 22 | 5 | 0 | 0 | 0 | 0 |
| Mean (°C, days) |
|---|
| < -5 | -5 - 0 | 0 - 5 | 5 - 10 | 10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | > 30 |
| 0 | 1 | 16 | 14 | 0 | 0 | 0 | 0 | 0 |
| Minima (°C, days) |
|---|
| < -5 | -5 - 0 | 0 - 5 | 5 - 10 | 10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | > 30 |
| 0 | 11 | 11 | 9 | 0 | 0 | 0 | 0 | 0 |
Precipitation
| Total | 55.4 mm (-21.8 mm, 71%) |
| Max Rain (Day) | 14.5 mm | 2nd |
| Max Rate | 40.9 mm/hr | 2nd |
| Days With |
|---|
| 0.0mm | 0.2mm | 2.0mm | 20.0mm |
Snow Falling | Snow Lying | Hail | Thunder | Fog |
| 13 | 18 | 9 | 0 |
-- | -- | -- | -- | -- |
Pressure
| Mean | 1015.6mb |
| Maximum | 1039.8mb |
| Minimum | 979.3mb |
