Weather Data summary for June 2017 for the Blenheim Meteorological station located at the Grovetown Park campus of the Marlborough Research Centre.
June 2017 mean temperature was close to average. June recorded 10 ground frosts and one air frost. Sunshine was slightly above average. Rainfall and wind-run were well below average.
162.7 hours sunshine for June was 108% of the long term average of 151.2 hours (1930-2016)
June 2016 recorded 153.4 hours sunshine
June 2015 recorded 174.0 hours sunshine
June 2014 recorded 133.4 hours sunshine
Total sunshine for the first six months of 2017 was 1266.3 hours; 48.9 hours higher (104%) than the long-term average (1217.4 hours). Four of the first six months of 2017 have recorded above average sunshine hours (January, February, May, June). March and April recorded lower than average sunshine.
June’s mean temperature of 8.8°C was 0.1°C above the long-term average temperature of 8.7°C (1986-2016).
June 2016 mean temperature was 10.1°C (6th warmest on record 1930-2017).
June 2015 mean temperature was 9.0°C.
June 2014 mean temperature was 10.8°C, (2nd warmest June on record).
June 2013 mean temperature was 8.9°C.
Table 1: June 2017 temperatures and frosts for Blenheim
|Mean Max||Mean Min||Mean Deviation||Total Ground Frosts||Total Air Frosts|
|1-7 June||12.8||4.6||8.7 =||0||0|
|8-14 June||15.1||3.7||9.4 +0.7||2||0|
|15-21 June||15.4||1.9||8.6 -0.1||5||1|
|22-28 June||13.0||4.0||8.5 -0.2||2||0|
|29-30 June||13.4||2.6||8.0 -0.7||1||0|
|1-30 June||14.1||3.5||8.8 +0.1||10||1|
The average daily maximum temperature of 14.1°C was 0.3°C above average
The average daily minimum temperature of 3.5°C was equal to the long-term average
The second week of June was slightly warmer than the other weeks, but on the whole the weekly temperatures throughout the month were fairly even.
Although the mean temperature for June 2017 was slightly above average it was considerably cooler than in 2014 and 2016, when June recorded very warm mean temperatures.
Ground Frosts (recorded at a height of 2.5 cm above a mown grass surface).
A ground frost is any temperature less than or equal to -1.0°C
June 2017 = 10
June 2016 = 10
June 2015 = 13
The coldest ground frost in June 2017 was -4.6°C recorded on 14th June
The coldest ground frost in June 2016 was -4.4°C recorded on 4th June
As well as the 10 days on which ground frosts were recorded, there were another eight days in June when the ground temperature was between 0 and -1.0; i.e. below zero but not quite cold enough to be recorded as a ground frost.
Air Frosts (recorded in a Stevenson Screen at a height of 1.5 m)
An air frost is any temperature below 0°C
June 2017 = 1
June 2016 = 1
June 2015 = 5
The coldest air frost in June 2017 was -1.4°C recorded on 14th June.
The coldest air frost in June 2016 was -0.1°C recorded on 3rd June.
Total rainfall in June of 18.4 mm was 30% of the long-term average (1930-2016) for June of 60.6 mm.
June 2016 rainfall was 76.8 mm.
June 2015 rainfall was 87.0 mm.
June 2014 rainfall was 98.3 mm.
June 2013 rainfall was 114.6 mm. (6th highest total on record 1930-2014)
Up until 29 June the rainfall total was 9.8 mm and heading for one of the lowest June totals on record. However, 8.6 mm of rain was recorded overnight on the 30th June, almost doubling the total. However, the June total was still only 30% of average.
For the seven years 2010 to 2016 June recorded above average rainfall. June 2017 is the first year since 2008 to have recorded well below average rainfall.
Rainfall for the 12 months July 2016 to June 2017
Monthly rainfall over the 12 months July 2016 to June 2017 has been highly variable. Six of the 12 months recorded well below average rainfall as indicated in Figure 1 (July, August, September, December, January, June). Three months recorded well above average rainfall (November, February and April). Three months recorded close to average rainfall (October, March and May).
Figure 1: Monthly and cumulative rainfall in Blenheim for the 12-months July 2016 to June 2017 compared to the long term average
Total rainfall for the 12 months July 2016 to June 2017 was 608.6 mm. This is 95% of the long-term average (641.1 mm). While this is slightly below the long-term average it is much higher than in the two previous years (July to June) both of which recorded well below average rainfall.
July 2014 to June 2015 = 347.4 mm (54% of LTA)
July 2015 to June 2016 = 491.2 mm (77% of LTA)
Total rainfall for the 24 months July 2014 to June 2016 was 835.7 mm, or only 65% of the long-term average of 1282.2 mm.
During the late winter and early spring of 2016 (July, August, September) it looked as if Marlborough was headed for another season of low rainfall. However, average and above average rainfall in October and November 2016 prevented the onset of a summer drought. These two months proved vital for the 2016-17 season given that rainfall in December 2016 and January 2017 was well below average.
Total rainfall for the six months January to June 2017 is 343.0 mm, 110% of the long-term average. The high April rainfall has more than offset the low rainfall in January and June.
Average daily wind run for June 2017 was 181.3 km, with an average wind speed of 7.6 km/hr. Well below the long-term average wind-run for June of 226.6 km (1996-2016).
January 2017 recorded high wind-run (122% of average). However, the five months from February to June 2017 have all recorded well below average wind-run; i.e. these five months have been much calmer than normal.
Plant & Food Research / Marlborough Research Centre