My May
Temperature: My mean temperature for the month was 7.6C, this May equals 2002 as the coldest I've recorded. The highest temperature was 18.8C on the 8th, the lowest maximum temperature for May in my records. The lowest was -3.0C on the 6th. This was the lowest temperature for May this early in the month in my records, frosts of this level are normally seen after the 17th. I recorded 8 days with temperatures at or below 0C. Looking through my records, only 2001 and 2002 have more. In both of these years, there was a series of frosts at the end of the month. 2001 had 11 days from the 20th to the 31st where the temperature was at or below 0C with the 31st recording -6.2C, my May record. 2002 had a series of frosts on 8 days from the 24th to the 31st with -5.7C being recorded on the 30th. As mentioned above, my lowest temperature for May is -6.2C on 2002 and the highest is 25.4C on the 4th May 2002.
Wind: The monthly wind run of 3468km is below the average of 3866km for the 8 years I have wind data for. This is the second lowest wind run for May in my records. The windiest May I've recorded is 2004 with 4483km of wind and the least was May 2003 with 3185km. At the other end of the scale, the 30th is currently the least windy of the year to date with a wind run of just 8km followed by the 5th with 14km. Prevailing wind direction was north east recorded 44% of the month, south 35%, south west 13%, north 3%, south east and north west 2% with others 1%. Maximum gust was 51km/h from the south west on the 3rd.
Rainfall: With 92.8mm, May was the third wettest I've recorded with 58.8mm or 64% of this falling in 1 day on the 3rd. This May daily total is only exceeded by 74.6mm on the 12 May 2006. May had 10 rain days, my 9 year average is 12. The wettest May I've recorded was 2006 with 159.4mm, the driest is 2007 with 21.2mm
| May 2008 Summary Temperature |
|
|---|---|
| Mean | 7.6 C |
| Mean Maximum | 12.8 C |
| Mean Minimum | 3.4 C |
| Maximum High | 18.8 C (8th) |
| Maximum Low | 11.0 C (20th) |
| Minimum High | 7.8 C (3rd) |
| Minimum Low | -3.0 C (6th) |
| Wind Speed and Direction | |
| Maximum Gust | 51 km/h (3rd) |
| Mean | 4.7 km/h |
| Wind Run | 3468 km |
| Max Daily Windrun | 349 km (20th) |
| Prevailing Direction | North East |
| Barometer | |
| Maximum | 1031.2 hPa (16th) |
| Minimum | 996.0 hPa (10th) |
| Mean | 1015.4 hPa |
| Max Daily Change | +14.6 hPa (11th and 14th) |
| Rainfall | |
| Days with Measured Rainfall (Greater than 0.2mm) | 10 |
| Max Daily Rainfall | 58.8 mm (3rd) |
| Monthly Rainfall | 92.8 mm |
| Humidity | |
| Maximum | 98 % (25th and 28th) |
| Minimum | 46 % (31st) |
| May 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 | 6.9 | 12.0 | 8.7 | 4.1 | 24 | 98 | South | 0.2 | 0.6 | 1002.4 | 1009.2 | -6.8 |
| Cloudy and cool with a few showers. Southerly winds turning NE in the evening. | ||||||||||||
| 2 | 1.8 | 12.0 | 5.6 | 6.8 | 44 | 162 | South | 0.8 | 10.2 | 999.7 | 1005.1 | +5.4 |
| Calm and sunny in the morning. A cold southerly change from midday with thunder storms and hail showers in the evening. | ||||||||||||
| 3 | 2.8 | 7.8 | 5.2 | 12.6 | 51 | 299 | South West | 3.4 | 58.8 | 1004.3 | 1015.8 | +11.5 |
| Cold southerly winds with showers, many with hail. Snow on the Port Hills. This was the wettest day since 29 June 2007. Looking at my records, a daily total of 50mm or more has been recorded on 10 days over the past 9 years including yesterday. Only May, June and October have recorded 2 years with daily totals over 50mm with the12th May 2006 recording 74.6mm, The other notable daily total is 73.4mm on August 6th 2004. The October 12th 2000 storm had a daily total of 56mm at my location. | ||||||||||||
| 4 | 2.3 | 11.4 | 5.4 | 2.3 | 22 | 56 | South | 0.6 | 2.8 | 1015.5 | 1018.3 | -2.8 |
| Morning showers clearing and cloud breaking in the afternoon with some sunny intervals. Cool southerly breeze. | ||||||||||||
| 5 | -0.6 | 10.1 | 4.3 | 0.5 | 10 | 14 | South | 0 | 0 | 1014.2 | 1017.0 | -2.8 |
| Morning frost, variable cloud, light southerly breezes. | ||||||||||||
| 6 | -3.0 | 11.1 | 3.3 | 1.3 | 19 | 30 | North East | 0 | 0 | 1012.5 | 1015.4 | -2.9 |
| The coldest morning this early in the year that I've recorded to date. Frost, sunny with light north to north east breezes. | ||||||||||||
| 7 | 0.3 | 13.4 | 7.0 | 4.7 | 29 | 111 | North East | 0 | 0 | 1005.9 | 1013.4 | -7.5 |
| Some cloud but mostly sunny with NE winds. | ||||||||||||
| 8 | 8.1 | 18.8 | 12.6 | 5.6 | 22 | 131 | North East | 0 | 0 | 997.8 | 1005.7 | -7.9 |
| Early light shower. Thin high cloud but mostly sunny and mild with NE breezes. | ||||||||||||
| 9 | 6.7 | 12.7 | 9.3 | 8.3 | 35 | 197 | South | 0.2 | 1.0 | 996.6 | 1007.6 | +11.0 |
| Cloudy with afternoon and evening drizzle, southerly winds. | ||||||||||||
| 10 | 6.4 | 12.8 | 9.4 | 5.2 | 25 | 124 | North East | 0.2 | 0.6 | 996.0 | 1007.8 | -11.8 |
| Early showers. Mostly sunny with some cloud at times. NE winds from late morning. | ||||||||||||
| 11 | 6.2 | 14.5 | 9.4 | 8.2 | 35 | 193 | South | 0 | 0 | 996.4 | 1011.0 | +14.6 |
| Cloud increasing and a brief shower around midday but remaining mostly sunny for the afternoon. Cool southerly winds. | ||||||||||||
| 12 | 0 | 12.5 | 6.0 | 1.2 | 20 | 29 | South | 0.2 | 0.2 | 1010.9 | 1014.8 | +3.9 |
| Morning shower. Cloud breaking and clearing in the evening. Light breezes. | ||||||||||||
| 13 | -1.1 | 13.1 | 5.9 | 2.4 | 20 | 58 | North East | 0 | 0 | 1009.7 | 1014.2 | -4.5 |
| Mostly sunny in the morning but cloud increasing in the afternoon. Light NE winds. | ||||||||||||
| 14 | 3.8 | 16.1 | 8.7 | 1.4 | 15 | 34 | South | 0 | 0 | 1010.3 | 1024.9 | +14.6 |
| Sunny with mostly clear skies and light breezes. | ||||||||||||
| 15 | 3.2 | 15.1 | 8.5 | 2.1 | 16 | 51 | North East | 0 | 0 | 1023.3 | 1030.4 | +7.1 |
| Some cloud but mostly sunny with light NE winds. | ||||||||||||
| 16 | -0.1 | 16.0 | 7.3 | 1.7 | 15 | 41 | North East | 0 | 0 | 1028.2 | 1031.2 | -3.0 |
| Clear and sunny with light winds. | ||||||||||||
| 17 | 4.5 | 13.6 | 9.6 | 5.5 | 34 | 131 | North East | 0 | 0 | 1024.0 | 1029.7 | -5.7 |
| Broken cloud with a cool NE wind. | ||||||||||||
| 18 | 5.6 | 14.8 | 10.5 | 4.3 | 22 | 101 | North East | 0 | 0 | 1020.7 | 1023.9 | -3.2 |
| Some high cloud but mostly sunny with light winds. | ||||||||||||
| 19 | 3.2 | 15.0 | 9.5 | 4.8 | 34 | 114 | North East | 0 | 0 | 1017.3 | 1021.2 | -3.9 |
| Some high cloud but mostly sunny with NE winds increasing in the evening. | ||||||||||||
| 20 | 11.0 | 14.1 | 12.2 | 14.7 | 41 | 349 | North East | 0.2 | 0.2 | 1013.9 | 1017.2 | -3.3 |
| Mostly cloudy with light showers in the morning. Gusty NE wind. | ||||||||||||
| 21 | 10.7 | 14.3 | 12.2 | 14.2 | 47 | 336 | North East | 0 | 0 | 1007.6 | 1013.6 | -6.3 |
| Broken cloud with gusty NE winds. | ||||||||||||
| 22 | 5.4 | 11.1 | 8.4 | 8.2 | 32 | 192 | South West | 0.6 | 8.2 | 1006.5 | 1013.2 | +6.7 |
| Overcast with rain from midday and cool southerly winds. | ||||||||||||
| 23 | 5.9 | 8.6 | 7.1 | 7.8 | 27 | 183 | South | 0.4 | 4.8 | 1011.3 | 1013.4 | -2.1 |
| Overcast with cool southerly winds. Showers morning and evening. | ||||||||||||
| 24 | 6.8 | 8.9 | 7.8 | 3.1 | 17 | 73 | South | 0.2 | 2.8 | 1011.3 | 1017.1 | +5.8 |
| Dull with low cloud and drizzle, light southerly winds. | ||||||||||||
| 25 | 4.7 | 10.6 | 7.9 | 4.8 | 25 | 115 | South | 0.4 | 1.4 | 1017.2 | 1025.2 | +8.0 |
| Broken cloud, some showers with cool southerly winds. | ||||||||||||
| 26 | 4.6 | 9.5 | 6.6 | 2.1 | 19 | 51 | South | 0 | 0 | 1025.1 | 1028.5 | +3.4 |
| Cloud breaking at times. Some drizzle with light southerly breezes. | ||||||||||||
| 27 | 2.1 | 10.6 | 6.2 | 2.2 | 21 | 52 | North East | 0 | 0 | 1021.4 | 1028.1 | -6.7 |
| Sunny with light NE winds. | ||||||||||||
| 28 | 0.3 | 12.5 | 4.7 | 2.2 | 16 | 52 | South | 0 | 0 | 1022.5 | 1027.3 | +4.8 |
| Morning frost, clear and sunny with light southerly breezes. | ||||||||||||
| 29 | -0.3 | 12.7 | 4.5 | 1.0 | 16 | 23 | North West | 0 | 0 | 1020.9 | 1026.4 | -5.5 |
| Frost. Clear and sunny with light breezes. | ||||||||||||
| 30 | -1.1 | 14.6 | 4.6 | 0.4 | 11 | 8 | North West | 0 | 0 | 1020.2 | 1024.8 | +4.6 |
| 31 | -0.5 | 16.5 | 7.6 | 2.0 | 19 | 49 | North West | 0 | 0 | 1016.0 | 1024.3 | -8.3 |
| Mostly sunny with high cloud increasing in the afternoon and some light drizzle in the evening. | ||||||||||||
