Frost reports 2023

[NZ Thunderstorm Soc]

White frost here, down to minis 2C.

[Richard]

Another ripper of a frost this morning -5.7deg

[darcyplumb]

Ice started forming here around 7pm last night, woke at 6am to a very solid freeze but fog developing with some melting of the frost. Now the fog has lifted and we are freezing again! The lowest temp during the night was -2.8deg C

[kiwisk8er]

We had a severe frost overnight, this morning in Mosgiel we got down to -6.8˚C.

[NZ Thunderstorm Soc]

Good frost here this morning, down to minus 3.5C here this morning with traces of frost in areas not exposed to the sun around 11.30am.

[Richard]

Not quite as cold this morning, only -4.8

[Nev]

Noticed MS's Tara Hills, Omarama site down to at least -9.6C this morning.

[Nev]

Tara Hills, Omarama first to break -10.0C this season - down to at least -10.6C this morning.

[Richard]

Thankfully no -10 here. Clouded over last evening so had wondered if that would kept that frost at bay, but no, cleared around midnight, reached down to -5 by sunrise.

[spwill]

Clear sky nights here lately but we are not getting the chilling that can happen in June, lows have been around 8C.
I think it is fair to say the frost free zones in the Auckland region will be expanding. See what the rest of Winter can bring with cold southerly outbreaks

[NZ Thunderstorm Soc]

Same as you here in Geraldine, Richard.
Clouded over yesterday afternoon and remained cloudy in the evening with a cloudy forecast for today so didn't bother to put the frost cloths over some plants, however it did clear away overnight with a frost this morning, getting down to minus 2.8C with a lovely blue dome day to follow.

[Richard]

This mornings frost is the coldest for 10 years, down to -7deg. Interesting how for for many years the frosts were steadily getting less, but the last 3 winters are seeing them getting heavier again.

[Bradley]

This mornings frost is the coldest for 10 years, down to -7deg. Interesting how for for many years the frosts were steadily getting less, but the last 3 winters are seeing them getting heavier again.

And being in La Nina years as well which if I’m not mistaken isn’t great for conditions for extreme frosts/extreme cold. Maybe Tony might have a theory on it hopefully?

[NZ Thunderstorm Soc]

Good frost here this morning, down to minus 4C. Some permafrost up there in the Downs.

[Nev]

This mornings frost is the coldest for 10 years, down to -7deg. Interesting how for for many years the frosts were steadily getting less, but the last 3 winters are seeing them getting heavier again.

Hmm... According to NIWA's Medbury data since 2016, you got down to -7.1C on 05 July 2021, -7.0C on 27 May 2021 and -7.0C on 11 Aug 2016.

Medbury Annual Air Frost Days ℅ NIWA
67 .. 2016
62 .. 2017
48 .. 2018
57 .. 2019
54 .. 2020
53 .. 2021
55 .. 2022
15 .. 2023 - to Jun 11

[TonyT]

This mornings frost is the coldest for 10 years, down to -7deg. Interesting how for for many years the frosts were steadily getting less, but the last 3 winters are seeing them getting heavier again.

And being in La Nina years as well which if I’m not mistaken isn’t great for conditions for extreme frosts/extreme cold. Maybe Tony might have a theory on it hopefully?

There is more north/south transport of air in LN years, so more significantly warm and significantly cold periods. So you would expect more frost and heavier frost in LN seasons, all else being equal.

[Simon Culling]

Interesting report from NIWA regarding their station at Lauder in Central Otago - it remained below freezing point continuously for over four and a half days from the 6th to the 11th June. From Google Maps, the location is just off the State Highway 85 (to the NE of the hamlet of Lauder) and at around 380m elevation. From the topographic map, it looks like the NIWA site is at the base of quite a long SW-NE valley.

https://twitter.com/NiwaWeather/status/ ... 7685911553

[Richard]

This mornings frost is the coldest for 10 years, down to -7deg. Interesting how for for many years the frosts were steadily getting less, but the last 3 winters are seeing them getting heavier again.

Hmm... According to NIWA's Medbury data since 2016, you got down to -7.1C on 05 July 2021, -7.0C on 27 May 2021 and -7.0C on 11 Aug 2016.

Medbury Annual Air Frost Days ℅ NIWA
67 .. 2016
62 .. 2017
48 .. 2018
57 .. 2019
54 .. 2020
53 .. 2021
55 .. 2022
15 .. 2023 - to Jun 11

Going by NIWA Neon network the 5th and 14th July 2021 it dropped to -6.8 deg, the same with the 27th May -6.8 deg, I can show a screen shot if you like. There's no data for 11thAug 2016

[Richard]

12.png

But looking back on this forum 11th Aug 2016 it was - 6,7deg

[Richard]

Dipped just below freezing this morning. Pleased we dont get the fog that hangs around all day like areas down south.

[NZ Thunderstorm Soc]

A lighter frost this morning here with it down to zero.

[Nev]

Hmm... According to NIWA's Medbury data since 2016, you got down to -7.1C on 05 July 2021, -7.0C on 27 May 2021 and -7.0C on 11 Aug 2016.

Going by NIWA Neon network the 5th and 14th July 2021 it dropped to -6.8 deg, the same with the 27th May -6.8 deg, I can show a screen shot if you like. There's no data for 11thAug 2016

According to NIWA's Cliflo archives, your low was -6.9C on 14 July 2021 and -7.1C yesterday (equal to 05 July 2021).

As previously discussed, I suspect the Neon data you're looking at only shows your temps at 10 minute intervals, rather than the absolute extreme temp between those intervals.

[Richard]

Understand. I'm going to ask why the absolute extreme temp shows on Cliflo but not Neon. .

[Richard]

Somewhere around -3.4 deg this morning, now the cloud has moved in - yuck

[NZ Thunderstorm Soc]

Ice on truck window with light frosting here this morning before cloud moved over. Down to zero.