Originally Posted by Oneiric 3
It is generally seen as good practice not to locate an official station in a 'frost hollow'.
Try as I might, I just can't take min data from D.A seriously, and most certainly not from a climatological perspective. If anything, minima there often deviates more from very nearby station data, and God knows there is plenty in the region, than Shannon's maxima does during hot weather from other stations in the greater region (Athenry, Gurteen, Moorpark etc) And as I showed last Summer, max temps during very hot weather often came in higher in nearby Adare Manor (SW of Shannon), than Shannon itself, and which would be in more open location than the airport.
It would seem that while Shannon's data is always up for debate, Dublin Aps is seen as sacrosanct. I don't subscribe to such selectivity. Having said that, D.A's mins are very probably 'correct' for that one particular spot, but I question its anomalous min figures as being 'representative' for the greater region, especially when other nearby data shows this not to be the case.
Edit: Wind direction at the time Dublin Apt was reporting a -5.0c figure:
While light, it was still straight in off the sea (of which it is only a hop, skip and jump away), while at the same time, Casement Aerodrome, which I believe would be more sheltered from the moderating effects of such a wind direction, was reporting just -1.1c at the time and Johnstown Castle, which would be located in a roughly similar distance from the sea (open to correction) than D.A, was reporting just 0.6c. Stations well inland at the time in the north Midlands and the North, were reporting temps of between -1.0c and -4.0c at the time, which would make more sense.
Sorry, not this Dublin v The Rest of the Country shíte again.
There is nothing wrong with DUB's readings. As I've said before, it's probably the best sited station in the country. It's the only truly rural enclosure, on flat open ground, without trees, with the nearest building being half a kilometre away. Being from the general area and knowing it intimately, to me it has always at least seemed colder as I was growing up. I note car temperature dropping a few degrees as I head up the Ashbourne road off the M50. It all relatively flat, rural landscape with little in the way of large trees, forested areas, etc.).
Dublin Airport's enclosure is 11-12 km from the nearest sea. Johnstown Castle's is actually just 4 km (to its NE, 11 km to its south). Wind there was NE that night.
Casement's enclosure is 16 km and a whole city from the sea and just 25 metres from a building to its west, 60 metres from the apron and hangars to its north and east. The wind at Casement was stronger and coming from the northeast (from the city) at the time of the coldest temperatures there (a couple of hours later than you showed).
Phoenix Park.. well, let's not even talk about that. It's just 15 metres from a large building to its southeast and 30 metres from a whole heap of others to its northeast. That while being totally enclosed by mature trees 50 metres to the west. It's so poorly located they didn't bother putting in an anemometer (by their own admission).
Dunsany's enclosure is 26 km from Dublin Airport's, so not in the same area. While is it relatively open too it does have a large cluster of buildings 150 metres to its northeast.
At the time you showed, Oak Park was at -3.7 °C, only just over a degree warmer than Dublin Airport. Mullingar had already gotten down to -4.8 °C at 9 pm before the cloud piled in. How do you explain that, given its more built-up location? At 9 pm Dublin Airport was only -0.8 °C.
I've been keeping a daily watch on Dublin's minima over the past several years and have absolutely no concerns over the data. The station is a very accurate representation of a large area of north Co. Dublin. I don't know why anything mentioning Dublin becomes almost part of some conspiracy theory by those from the west. Listen to the UKMO forecasts and you'll hear them always say "these are city temperatures; rural locations will be several degrees colder". Well, they're right.