Nev wrote:Whenuapai Aero's -3.0C on Sunday is nowhere near a record. It's coldest temp on record was -4.9C in June 1951 from records going back to 1946 (records cease between 1993-2004).
But that -4.9 temperature was 64 years ago, so maybe the -3.0 could be the coldest since then
Whenuapai Aero has dipped below -3.0C on at least a dozen days prior to 1993, the most recent being -3.5C in July 1983.
A very white frost here this morning. Cloud cleared around 10pm allowing the temp to drop.
Bottomed out at -3.0°C. With the 14mm of cold rain we had yesterday I'm picking there's a bit of ice around the place.
So now a stunning winters morning. Currently sitting on -2.4°C.
I find that a bit hard to believe that Nelson gets 88 ground frosts a year compared to 70 for Chch, is that taken right in Nelson though,i know Stoke just over the hill gets a lot more than the city thanks to being on the flat land.
I don't know exactly where either statistics are from - could be Nelson airport or from Chch Botanics... I've had the spreadsheet since 2003 and it mentions that the exact locations are available in a separate table but I don't have that.
The Nelson station gets 20% more sun than Chch from May-Sept so it would make sense to have more frosts with more clear nights...
We got to -3.2°C this morning just after 3am before clouding over and then a shower of rain came at 6am when it was still -1.5°C. Suffice to say it made the roads very slippery. Almost ended up on my arse walking to my truck!
Skywatcher wrote:I don't know exactly where either statistics are from - could be Nelson airport or from Chch Botanics... I've had the spreadsheet since 2003 and it mentions that the exact locations are available in a separate table but I don't have that.
The Nelson station gets 20% more sun than Chch from May-Sept so it would make sense to have more frosts with more clear nights...
It's quite easy to get a table downloaded from NIWA, with 20-odd stations cited. Means for 1981-2010: Christchurch Gardens has 80.4 ground frost days per annum, Nelson Aero 86.2. The Gardens would be perhaps a little warmer than a "typical" Ch'ch site, but I'm not sure about Nelson Aero air minima as compared with other sites in the general area.
Anywhere low lying around Nelson will catch the frost, Interestingly Nelson Airport is right on the coasal fringe which seems to offer little protection there.
spwill wrote:Interestingly Nelson Airport is right on the coasal fringe which seems to offer little protection there.
Not always the case though when it comes to cold air drainage, a good example is areas north of CHCH, some of the harder frosts are close to the sand hills, once the cold air reaches near the coast its cooled to its max before moving out over the warmer water
We got to -2.4°C this morning and even worse ice than yesterday. Rain cleared about 5pm and then cooled quickly. Was quite tricky on my 5am run.
Currently on -1.1°C with thick fog.
Yep, great day in Reefton.
spwill wrote:Interestingly Nelson Airport is right on the coasal fringe which seems to offer little protection there.
Not always the case though when it comes to cold air drainage, a good example is areas north of CHCH, some of the harder frosts are close to the sand hills, once the cold air reaches near the coast its cooled to its max before moving out over the warmer water
I can support this with an interesting thing that happened here in UK in 2010 where a station called Crosby right on the coast went down to -17.8C. The sand dunes cooled even quicker than the air around them, and with snow on the ground further inland, it was just the perfect catalyst for rapidly declining temperatures. It would never normally happen, but the right set of ingredients came together to deliver that eye opener.
Liverpool, UK
USDA zone 9a/3 (UK zone)..
Lowest winter low on average (each year): -4C
Highest summer high on average (each year): 27C
Highest maximum on record: 35.2C (July 2006)
Lowest minimum on record: -10.5C (December 2010)
