What makes Alexandra so hot in the summer

[mattyj46]

You often hear unoffical report of 37C+ temperatures in Alexandra, I'm just wondering what makes the temperatures so hot in that area of NZ?

Thanks.

[Manukau heads obs]

low humidity
greatest distance away from the relativly cool ocean
sheltered from cool sea breezes
sheltered from prevailing cooler winds
dark soil type

[spwill]

Also- fohn wind flows, can get plenty of sunshine due to low dewpoints and high country sheltering, dry bare ground heats quickly, fairly low lying.

[Manukau heads obs]

yes, i forgot that fact, the low humidity/low DP, means also then less cloud build up in the afternoon , so the heat keeps on building

[mattyj46]

Awesome, thanks for the quick replies!

[Storm Struck]

Another interesting point to note is that Cromwell which is 15 minutes drive from Alexandra is the most Central town in New Zealand.
By that i mean the distance from the West-East coasts, so it can be considered a neighbouring dust bowl with Alexandra.
Cheers
Jason.

[RWood]

I'm a Central Otago fan, having spent plenty of time there in my earlier years, but let's not get too carried away.

Average daily max (Jan, Feb) values:

Te Aroha 25.2 25.5
Whakatane 24.3 24.5
Gisborne 24.7 24.3
Blenheim 23.5 23.4
Darfield 24.0 23.8
Cromwell 24.4 24.2
Alexandra 23.7 23.6

In a typical summer sequence the area is subject to cooler SW/W airflows between the hotter spells. All of these temperature means are what Australians would call "mild". The record value at Alex is (from memory) 38.7C, a few years back.

[mattyj46]

I'm a Central Otago fan, having spent plenty of time there in my earlier years, but let's not get too carried away.

Average daily max (Jan, Feb) values:

Te Aroha 25.2 25.5
Whakatane 24.3 24.5
Gisborne 24.7 24.3
Blenheim 23.5 23.4
Darfield 24.0 23.8
Cromwell 24.4 24.2
Alexandra 23.7 23.6

In a typical summer sequence the area is subject to cooler SW/W airflows between the hotter spells. All of these temperature means are what Australians would call "mild". The record value at Alex is (from memory) 38.7C, a few years back.

I'd take a Central Otago summer over anywhere else in NZ anyday , always seems to be warm temps in the summers, I remember last summer there were unoffical reports of 40C, was an article in the Southland Times, might have to try and dig her out.

[spwill]

In a typical summer sequence the area is subject to cooler SW/W airflows between the hotter spells.

I see Central Auckland has a higher average daily max temp and a much higher average daily min than Alex.

For Northern locations you also need to consider dewpoint temp.
\

[sthguy]

LX is not a 'sea breeze' free zone. Neither is Queenstown. In anticyclonic weather a sea breeze circulation goes right into the heart of Central by late afternoon. When you think that the daily max is within 5C from the southern coast, to central, you realise that while it is a close to a 'continental' location was we have in NZ we are still just a small island.

But in terms of Sth vs Nth Island locations, Central Otago is a warm spot in summer. It is a lot closer to the South Pole than those Nth Island centres.

Jan - Oct daily max {Niwa}

NELSON 22.4 22.4 20.8 18.1 15.2 12.9 12.4 13.1 14.9 16.8
BLENHEIM 23.8 23.6 22 19 15.8 13.3 12.8 13.8 16 18.1
WESTPORT 20 20.4 19.5 17.2 14.7 13 12.6 13.2 14.3 15.3
KAIKOURA 20.6 20 18.8 16.6 14.1 11.6 10.9 11.5 13.6 15.3
HOKITIKA 19.4 20 18.7 16.7 14.2 12.3 12 12.5 13.9 15.1
CHRISTCHURCH 22.5 22.2 20.4 17.8 14.6 11.7 11.3 12.4 14.9 17.4
MT COOK 20.3 20.8 17.9 14.5 10.8 7.3 6.4 8.4 11.6 14
LAKE TEKAPO 21.5 21.6 18.7 15 10.8 6.9 5.9 8.1 11.7 14.6
TIMARU 21.1 20.9 19.3 16.6 13.3 10.6 10.1 11.4 14.2 16
MILFORD SOUND 18.9 19.5 18 15.6 12.3 9.5 9.1 11.2 13.1 14.4
QUEENSTOWN 22.6 22.7 19.9 16.1 11.9 8.6 8.2 10.3 13.5 16.2
ALEXANDRA 23.5 23.8 21.5 17.5 12.4 7.5 7.9 11.4 15 17.5
MANAPOURI 20.7 20.8 18 14.6 12 8.3 8.2 9.6 12.6 14.9
DUNEDIN 18.9 18.7 17.2 15.5 12.6 10.2 9.8 11 12.8 14.6
INVERCARGILL 18.6 18.8 17.2 15 12.2 9.7 9.5 11 12.9 14.4

[RWood]

Yes, in those more northern locations higher dewpoints can be quite oppressive at times.

Reports of 40C are always "unofficial" - as has been detailed in past posts on this forum many times, only a tiny handful of credible 40C+ readings have ever occurred in NZ, all of them on the same day.

[spwill]

the daily max is within 5C from the southern coast, to central,

On sunny sea breeze days in summer the difference can be more like 10 to 15C between the coast and Alex.

[Myself]

Warmest summers in NZ occur in isolated spots in inland BoP, inland Hawke's Bay and possibly inland Waikato. There are places in all these regions where average highs in Jan/Feb are 25C.
Maybe then the hottest in terms of combined heat and humidity would be the likes of Kawerau, inland Waikato and possibly parts of inland Northland.

[NZstorm]

Henderson, west Auckland seems to be a warm spot relative to the rest of NZ. A little bit sheltered there from the sea breezes.

[Manukau heads obs]

yes, that eastern waikato area is where the SW and NE sea breeze meets....and which has been warmed up over the land as it moves inland

I live near the coast here, and the sea breeze will drop the temperature from 25C to 23C, but will also increase the DP by 2C, making it more uncomfortable

[spwill]

Warmest summers in NZ occur in isolated spots in inland BoP, inland Hawke's Bay and possibly inland Waikato. There are places in all these regions where average highs in Jan/Feb are 25C.

Need to also condsider temp mins, north of Hamilton they average above 14C.

[Andy]

I am in Alex till monday, already it is hot and sunny with a light NW wind. temp 29 degrees. (32.6 yesterday)

Here is a few links for those that are interested.

http://air.orc.govt.nz/airinfo/showsite ... st=60&s=89

http://www.alexandra.co.nz/

[mattyj46]

I am in Alex till monday, already it is hot and sunny with a light NW wind. temp 29 degrees. (32.6 yesterday)

Here is a few links for those that are interested.

http://air.orc.govt.nz/airinfo/showsite ... st=60&s=89

http://www.alexandra.co.nz/

Cheers for the links, wonder if they'll get that weather station up on www.alexandra.co.nz before January.

[mattyj46]

Does anyone know if there are any weather stations online in Alex? Can't seem to find many live data.

[Manukau heads obs]

http://www.alpnz.co.nz/wx/
in Clyde
and
http://homepages.ihug.co.nz/~jim.ryan/weather2/
in Arrowtown
both near, but no cigar