NZ Weather Forum

MetService January 2020 Summary - Parched soils

It was an extremely dry January, with a lack of rain makers coming in from any direction. Persistent highs sat over the Tasman Sea for the first half of the month, producing strong southwesterlies and well below average temperatures. Intense high pressure prevailed across all New Zealand from mid month, pushing the mercury to unusually hot values.

Most of the North Island, and northern and eastern regions of the South Island, recorded less than 35 percent of normal January rainfall. The exceptions were Gisborne and Hawkes Bay with around half the normal rainfall. In parts of Northland, Auckland, Waikato, Coromandel, inland Bay of Plenty, Nelson and Canterbury, record or near record low January totals were experienced, with totals less than 10 percent of January normal.

The extended dryness through January, coupled with the earlier wind, and recent heat, resulted in significant to severe soil moisture deficit across the North Island, as well as in all northern and eastern regions of the South Island.

Jan 2020 Average Temps, Rainfall, Sunshine and departures from 1981-2010 normals ℅ NIWA

Site                     T-max °C      T-min °C      T-mean °C     Rain mm      Sun hrs

Auckland, Mangere       23.5  +0.1    15.9   0.0    19.7  +0.1      8   14%    278  119%
Auckland Aero           23.7  +0.1    16.1  +0.1    19.9  +0.1      8   12%
Tauranga Aero           25.4  +1.5    15.1   0.0    20.2  +0.7     19   25%    n/a   n/a
Hamilton Aero           25.6  +1.3    11.1  -1.3    18.3   0.0      9   11%
Hamilton, Ruakura       24.7  +0.7    11.9  -1.0    18.3  -0.1      6    8%    278  121%
Wellington, Kelburn     19.4  -0.9    13.5   0.0    16.5  -0.4     27   36%    189   76%
Christchurch Aero       23.3  +0.7    11.6  -0.3    17.5  +0.3      3    9%    239  100%
Dunedin, Musselburgh    18.6  -0.3    12.0  +0.4    15.3   0.0     34   46%    254  141%
Greymouth Aero          19.3  -0.5    12.1  -0.3    15.7  -0.4    113   54%    201  100%

Nev wrote: ↑Sat 01/02/2020 20:18 A generally very cool start to the month, contrasting with a very warm end, lead to a very normal national average temp. Also very sunny for most places except for the lower North Island, Marlborough and the central West Coast.

MetService January 2020 Summary - Parched soils

It was an extremely dry January, with a lack of rain makers coming in from any direction. Persistent highs sat over the Tasman Sea for the first half of the month, producing strong southwesterlies and well below average temperatures. Intense high pressure prevailed across all New Zealand from mid month, pushing the mercury to unusually hot values.

Most of the North Island, and northern and eastern regions of the South Island, recorded less than 35 percent of normal January rainfall. The exceptions were Gisborne and Hawkes Bay with around half the normal rainfall. In parts of Northland, Auckland, Waikato, Coromandel, inland Bay of Plenty, Nelson and Canterbury, record or near record low January totals were experienced, with totals less than 10 percent of January normal.

The extended dryness through January, coupled with the earlier wind, and recent heat, resulted in significant to severe soil moisture deficit across the North Island, as well as in all northern and eastern regions of the South Island.

Jan 2020 Climate Anomaly Maps ℅ NIWA.png


Some very preliminary Jan 2020 figures for the main centres:

Code: Select all

Jan 2020 Average Temps, Rainfall, Sunshine and departures from 1981-2010 normals ℅ NIWA

Site                     T-max °C      T-min °C      T-mean °C     Rain mm      Sun hrs

Auckland, Mangere       23.5  +0.1    15.9   0.0    19.7  +0.1      8   14%    278  119%
Auckland Aero           23.7  +0.1    16.1  +0.1    19.9  +0.1      8   12%
Tauranga Aero           25.4  +1.5    15.1   0.0    20.2  +0.7     19   25%    n/a   n/a
Hamilton Aero           25.6  +1.3    11.1  -1.3    18.3   0.0      9   11%
Hamilton, Ruakura       24.7  +0.7    11.9  -1.0    18.3  -0.1      6    8%    278  121%
Wellington, Kelburn     19.4  -0.9    13.5   0.0    16.5  -0.4     27   36%    189   76%
Christchurch Aero       23.3  +0.7    11.6  -0.3    17.5  +0.3      3    9%    228*  96%
Dunedin, Musselburgh    18.6  -0.3    12.0  +0.4    15.3   0.0     34   46%    254  141%
Greymouth Aero          19.3  -0.5    12.1  -0.3    15.7  -0.4    113   54%    201  100%

* Missing 1 days data

cbm wrote: ↑Sun 09/02/2020 09:08 Does anyone know what sites NIWA is referring to in this from their Jan 2020 summary, or if this is an error?

"Of the available, regularly reporting sunshine observation sites, the sunniest four locations in 2020 so far are Waikato (323 hours), Wider Nelson (308 hours), Tasman (296 hours) and Northland (283 hours)."

If the dots on their sun map mean anything, they have a recording site near Te Awamutu?

cbm wrote: ↑Sun 09/02/2020 09:42 So in Clifo to get monthly sun, do you just tally the days of the month-i,e,Jan 1…Jan31,

Nev wrote: ↑Sun 09/02/2020 09:49

cbm wrote: ↑Sun 09/02/2020 09:42 So in Clifo to get monthly sun, do you just tally the days of the month-i,e,Jan 1…Jan31,

Yes