Meteorological data summary for October 2017 for the Blenheim Meteorological station located at the Grovetown Park campus of the Marlborough Research Centre.
October 2017 was warm, with above average sunshine hours, below average rainfall, and well below average wind-run.
Table 1: Weekly weather data during October 2017
|1st – 7th||18.2||7.1||12.6 (-0.5)||14.4||48.5|
|8th – 14th||18.3||9.4||13.9 (+0.8)||17.8||32.1|
|15th – 21st||18.7||7.8||13.3 (+0.2)||0.0||62.8|
|22nd – 28th||19.6||8.4||14.0 (+0.9)||0.2||68.9|
|29th – 31st (3 days)||24.1||12.3||18.2 (+5.1)||0.0||35.1|
|1st – 31st October 2017||19.2
(1986 – 2016)
LTA – Long Term Average
Mean temperature of 13.9°C was 0.8°C above the long-term average temperature for October of 13.1°C (1986-2016).
October 2016 mean temperature was 13.9°C.
October 2015 mean temperature was 13.7°C.
October 2014 mean temperature was 13.0°C.
October 2013 mean temperature was 14.1°C.
The warmest maximum temperature of 24.7°C was recorded on 31 October 2017.
The coolest minimum temperature of 4.4°C was recorded on 19 October 2017.
In four of the five years 2013 to 2017, the October mean temperature was well above average. However, in the 11 years 2002 to 2012, the mean October temperature was never above average.
No ground or air frosts were recorded in Blenheim in October 2017.
NB: This is the first year since 1998 when a ground frost has not been recorded in Blenheim during October.
Two ground frosts and no air frosts were recorded in October 2016.
The long-term average number of ground frosts for October is two.
247.4 hours sunshine for October was 109% of the long-term average for October of 227.2 hours (1930-2016).
October 2016 recorded 233.9 hours sunshine.
October 2015 recorded 271.7 hours sunshine.
October 2014 recorded 270.0 hours sunshine.
October 2013 recorded 222.3 hours sunshine.
Total sunshine for January to October 2017 was 2038.9 hours, 103% of the long-term average of 1976.2 hours.
Sunniest town in New Zealand update.
The sunniest place in New Zealand during October 2017 was Tekapo, which recorded 261.2 hours sunshine, 13.7 hours ahead of second place getter Richmond with 247.5 hours.
At the end of September 2017, Whakatane had the highest sunshine total for the first nine months of 2017. However, Richmond and Blenheim recorded 34.2 and 34.1 hours more sunshine respectively, than Whakatane during October. This has pushed Whakatane down into third place for the year to date. Blenheim is sitting in second place 7.1 hours behind Richmond, so these top three towns are all in the race for sunniest town in New Zealand for 2017.
Current sunshine totals and rankings to the end of October 2017 are:
Richmond 2046.0 hours (7.1 hours ahead of Blenheim)
Blenheim 2038.9 hours
Whakatane 2028.3 hours
Napier 1978.1 hours
Tekapo 1944.6 hours
Appleby 1919.2 hours
Nelson 1812.7 hours
Rainfall total of 32.4 mm was 57% of the long-term average for October of 56.6 mm (1930-2016).
October 2016 rainfall was 58.6 mm.
October 2015 rainfall was 6.0 mm.
October 2014 rainfall was 22.4 mm.
October 2013 rainfall was 56.0 mm.
Rain was recorded in Blenheim on six days during October 2017. Five of these rain days were the 6th, 7th, 8th, 9th, 11th October. The only other day to record rain was 27 October with only 0.2 mm; i.e. there was basically no rain from 12 to 31 October. The highest one day total was 14.0 mm recorded on the 7 October, followed by 11.8 mm recorded on 11 October.
You may recall in last month’s press release that it was stated that each of the three months July, August and September 2017 recorded rain on 13 days during the month. There were less than half the number of rain days in October 2017, compared to the previous three months.
Total rainfall for January to October 2017 of 553.4 mm was 102% of the long-term average of 544.6 mm.
Topsoil moisture was 35.3% on 1 October 2017 and on 16 October soil moisture was still 35.5%. However, with no significant rain recorded from 12 to 31 October, the topsoil moisture had fallen to 23.8% on 31 October 2017; i.e. the topsoil had lost 11.7% moisture over 15 days. This moisture loss over those 15 days was approximately 50% of the available topsoil moisture at the Grovetown Park weather station. This indicates how rapidly topsoil moisture can be lost from an actively growing grass sward (lawn/pasture) during October, without rainfall.
October 2017 average daily wind-run was 241.4 km. This was 80% of the October mean (1996-2016) of 301.4 km. There were only five days during October that recorded above average wind-run
October 2016 recorded average daily wind-run of 255.1 km.
As detailed last month, January 2017 is the only month so far in 2017 to have recorded above average wind-run.
Evapotranspiration for October 2017, was 109.7 mm, compared to the long-term average of 101.8 mm.
Plant & Food Research / Marlborough Research Centre