May Summary;
About average temperature and well below average rainfall, cold end to the month.
- May was just above my average temperature of 9.2C with 9.5C.
- The warmest May is 2007 with 11.6C, the coolest 2001 and 2009 with 7.5C.
- The coldest temperature was -2.5C. The lowest May temperature I've recorded was in 2001 with -6.2C.
- Seven air frosts were recorded (Air temperature at or below 0). My average is 4.
- One day failed to reach 10C.
- Seventeen days reached or exceed 15C, my average is 10.
- Five days reached or exceeded 20C, my average is 3.
- One day reached or exceeded 25C. Only one other May day has reached 25C in my records, May 4th 2002 with 25.4C
- Wind run was 84% of my average of 3851km with 3217km.
- The barometer recorded below average pressure for the month with 1010.0 hPa. My average is 1012.5 hPa.
- Rainfall was just 15% of my average expected rainfall of 85mm with just 12.5mm,
- The driest May is 2012 with 13mm.
- The wettest May is 2009 with 193mm.
| May 2015 Summary Temperature | |
|---|---|
| Mean | 9.5 C |
| Mean Maximum | 15.9 C |
| Mean Minimum | 3.9 C |
| Maximum High | 25.2 C (6th) |
| Maximum Low | 14.1 C (6th) |
| Minimum High | 8.6 C (25th) |
| Minimum Low | -2.5 C (31st) |
| Wind Speed and Direction | |
| Maximum Gust | 65 km/h (21st) |
| Mean | 4.9 km/h |
| Wind Run | 3217 km |
| Max Daily Windrun | 282 km (15th) |
| Prevailing Direction | East North East |
| Barometer | |
| Maximum | 1031.1 hPa (3rd) |
| Minimum | 986.3 hPa (12th) |
| Mean | 1010.0 hPa |
| Max Daily Change | -14.2 hPa (11th) |
| Rainfall | |
| Days with Measured Rainfall (0.5mm or more) |
8 |
| Max Daily Rainfall | 4.0 mm (12th) |
| Monthly Rainfall | 12.5 mm |
| Humidity | |
| Maximum | 100 % (Several Days) |
| Minimum | 30 % (7th) |
| 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 | 1.5 | 16.8 | 8.6 | 2.0 | 19 | 120 | East Nth East | 0 | 0 | 1020.5 | 1026.6 | +6.1 |
| Few clouds but mostly sunny with light winds tending NE. | ||||||||||||
| 2 | 4.5 | 15.9 | 9.7 | 2.7 | 20 | 61 | East Nth East | 0 | 0 | 1025.4 | 1028.3 | +2.9 |
| Clear and sunny, light NE winds | ||||||||||||
| 3 | 3.0 | 15.0 | 8.9 | 4.1 | 28 | 92 | East Nth East | 0 | 0 | 1027.5 | 1031.1 | +3.6 |
| Mist and low cloud clearing late morning with light variable breezes turning cooler NE in the afternoon with increasing cloud. | ||||||||||||
| 4 | 6.8 | 19.2 | 11.5 | 2.4 | 22 | 46 | East Nth East | 0 | 0 | 1023.3 | 1028.9 | -5.6 |
| Morning fog caused delays at the airport cleared late morning then sunny with some high cloud. Light variable winds tending NE | ||||||||||||
| 5 | 9.1 | 16.4 | 12.5 | 4.1 | 20 | 93 | East Nth East | 0 | 0 | 1012.0 | 1025.2 | -13.2 |
| Morning mist clearing high cloud thickening in the afternoon with a few spots of rain later in the afternoon, light NE winds. | ||||||||||||
| 6 | 14.1 | 25.2 | 19.1 | 6.0 | 38 | 137 | East Nth East | 0 | 0 | 1000.3 | 1011.7 | -11.4 |
| Mostly cloudy but some sunny intervals, mild with north to NE winds. This is the second warmest May day I've recorded. Warmest is currently 4th May 2002 with 25.4C. | ||||||||||||
| 7 | 12.5 | 24.4 | 17.5 | 6.5 | 51 | 141 | North Nth West | 0 | 0 | 998.2 | 1003.0 | -4.8 |
| Clear and sunny with mild northerly winds. | ||||||||||||
| 8 | 7.9 | 19.7 | 13.9 | 5.6 | 37 | 111 | North Nth West | 0 | 0 | 996.8 | 1000.9 | +4.1 |
| Clear and sunny with mild northerly winds from mid morning. | ||||||||||||
| 9 | 3.6 | 18.6 | 11.2 | 2.4 | 20 | 55 | East Nth East | 0 | 0 | 996.8 | 1000.4 | -3.6 |
| High cloud for most of the day, breaking later in the afternoon, light north to NE winds. | ||||||||||||
| 10 | 5.8 | 18.7 | 11.2 | 1.8 | 18 | 40 | East Nth East | 0 | 0 | 999.0 | 1005.4 | +6.4 |
| Morning cloud breaking in the afternoon. Light breezes turning cooler NE from mid afternoon. | ||||||||||||
| 11 | 7.7 | 20.4 | 14.4 | 6.3 | 34 | 145 | East Nth East | 0 | 0 | 989.3 | 1003.5 | -14.2 |
| Mostly cloudy with NE winds turning northerly from late afternoon | ||||||||||||
| 12 | 3.3 | 19.1 | 10.5 | 5.0 | 43 | 104 | East Nth East | 1.0 | 4.0 | 986.3 | 998.5 | +12.2 |
| NE winds turning mild northerly from late morning. Colder southerly change in the afternoon with rain clearing by evening. | ||||||||||||
| 13 | 2.7 | 20.1 | 11.4 | 7.2 | 43 | 164 | East Nth East | 0 | 0 | 992.9 | 999.8 | +6.9 |
| Clear and sunny, NE winds turning mild northerly from late morning | ||||||||||||
| 14 | 7.8 | 17.3 | 11.5 | 2.4 | 24 | 53 | East Nth East | 0 | 0 | 994.1 | 998.9 | -4.8 |
| Cloudy for most of the day but cloud breaking from mid afternoon. Light breezes tending NE. | ||||||||||||
| 15 | 6.8 | 10.8 | 9.5 | 13.8 | 50 | 282 | South | 0.5 | 3.0 | 993.0 | 1004.3 | +11.3 |
| Overcast with showers. cold southerly winds strengthening in the afternoon. | ||||||||||||
| 16 | 5.1 | 11.8 | 9.4 | 7.4 | 36 | 143 | South | 0.5 | 1.0 | 1004.4 | 1016.8 | +12.4 |
| Overcast with morning showers, southerly winds dying out in the afternoon. | ||||||||||||
| 17 | 4.3 | 14.3 | 9.6 | 2.8 | 18 | 61 | East Nth East | 0 | 0 | 1016.4 | 1022.2 | +5.8 |
| Morning cloud breaking to a sunny afternoon. Light northerly winds turning NE in the afternoon. | ||||||||||||
| 18 | 3.6 | 19.2 | 10.4 | 2.3 | 29 | 46 | South | 0 | 0 | 1008.9 | 1017.3 | -8.4 |
| Morning cloud clearing by midday to a sunny afternoon. Light mild northerly winds turning southerly in the evening. | ||||||||||||
| 19 | 7.5 | 13.6 | 10.6 | 3.7 | 26 | 78 | South | 0 | 0 | 1015.9 | 1022.4 | +6.5 |
| Morning cloud breaking mid morning but returning in the evening. Light southerly winds turning NE from late afternoon. | ||||||||||||
| 20 | 4.0 | 13.5 | 8.7 | 4.9 | 29 | 113 | East Nth East | 0 | 0 | 1008.4 | 1020.7 | -12.3 |
| Some high cloud but mostly sunny with cool NE wind. | ||||||||||||
| 21 | 6.9 | 21.8 | 13.7 | 7.1 | 65 | 151 | East Nth East | 0.5 | 1.0 | 997.8 | 1009.2 | +11.4 |
| Clear and sunny with NE winds turning mild nor'west early afternoon. A southerly change in the evening with a brief period of rain and strong winds around 11pm. | ||||||||||||
| 22 | 1.6 | 12.0 | 6.8 | 4.8 | 44 | 94 | East Nth East | 0.5 | 0.5 | 1007.8 | 1015.6 | +7.8 |
| Showers and southerly clearing before dawn. Cool, clear and sunny with light breezes in the morning turning NE in the afternoon. | ||||||||||||
| 23 | -2.3 | 14.6 | 4.9 | 0.8 | 12 | 14 | East Nth East | 0 | 0 | 1000.2 | 1008.4 | -8.2 |
| First frost of the year. Clear and sunny with light breezes tending NE. | ||||||||||||
| 24 | -1.1 | 14.7 | 4.6 | 5.7 | 54 | 114 | South | 0.5 | 1.5 | 991.5 | 1000.9 | -9.4 |
| Morning frost, sunny with light winds til mid afternoon. Cloud increasing with a cold southerly change from mid afternoon with showers in the evening | ||||||||||||
| 25 | -0.8 | 8.6 | 4.7 | 14.6 | 55 | 275 | South | 0.5 | 1.0 | 998.2 | 1007.3 | +9.1 |
| Early showers with sleet clearing. Dusting of snow on the port hills melting by mid day. Mostly sunny with a cold southerly wind. | ||||||||||||
| 26 | 1.4 | 11.1 | 6.5 | 11.6 | 39 | 239 | South | 0 | 0 | 1007.0 | 1012.8 | +5.8 |
| Mostly cloudy with cold southerly wind. | ||||||||||||
| 27 | 0.8 | 11.4 | 6.7 | 9.2 | 37 | 188 | South | 0 | 0 | 1012.3 | 1022.2 | +9.9 |
| Few clouds but mostly sunny with southerly winds easing in the afternoon and dying away in the evening. | ||||||||||||
| 28 | -2.4 | 11.8 | 3.3 | 0.3 | 11 | 6 | East Nth East | 0 | 0 | 1022.0 | 1028.6 | +6.6 |
| Frost, sunny with light breezes. | ||||||||||||
| 29 | -2.3 | 10.9 | 3.6 | 2.1 | 20 | 48 | East Nth East | 0 | 0 | 1020.6 | 1028.4 | -7.8 |
| Morning frost, clear and sunny with light breezes tending NE. | ||||||||||||
| 30 | -0.6 | 11.8 | 5.2 | 1.6 | 15 | 36 | East Nth East | 0 | 0 | 1014.0 | 1020.8 | -6.8 |
| Cloudy and cool with light NE breezes. | ||||||||||||
| 31 | -2.5 | 15.4 | 4.9 | 1.2 | 19 | 27 | East Nth East | 0 | 0 | 1013.3 | 1016.2 | -2.9 |
| Morning frost. Few clouds but mostly sunny with light NE breezes from late morning. | ||||||||||||
