One interesting thing, it was done, while searching for the nearly impossible (from the main South European countries, Portugal is quite probably the less studied climatologically) I did managed to get some interesting data, though from Algarve (unfortunately the warmest areas in Algarve close to Monchique and others more inland, are still without data):
Loulé-Alte, 2006-2010
Janeiro 3.54ºC//19.06ºC
Fevereiro 5.48ºC//19.72ºC
Março 7.00ºC//22.28ºC
Abril 8.44ºC//24.24ºC
Maio 10.78ºC//27.36ºC
Junho 14.30ºC//31.22ºC
Julho 17.10ºC//35.40ºC
Agosto 17.06ºC//35.18ºC
Setembro 14.78ºC//31.44ºC
Outubro 11.68ºC//27.54ºC
Novembro 6.78ºC//22.92ºC
Dezembro 4.98ºC//19.34ºC
Min. Abs. -5.5ºC
Max. Abs. 44.4ºC
Castro Marim-Junqueira, 2006-2010:
Janeiro 5.60ºC//17.46ºC
Fevereiro 6.58ºC//18.96ºC
Março 8.10ºC//21.36ºC
Abril 10.24ºC//23.50ºC
Maio 12.42ºC//27.06ºC
Junho 16.36ºC//31.32ºC
Julho 18.74ºC//35.58ºC
Agosto 18.80ºC//35.08ºC
Setembro 16.88ºC//30.84ºC
Outubro 13.64ºC//26.92ºC
Novembro 9.18ºC//21.92ºC
Dezembro 6.42ºC//18.02ºC
Min. Abs:-2.1ºC
Max. Abs: 43.5ºC
http://www.meteopt.com/forum/climatologia/o-clima-do-interior-algarvio-6013.html
And this was only possible because of climate research for agriculture practices.
Unfortunately and as it is explained on this thread, none is located on areas with the biggest summer potential on the region, though the values are not bad. So until now, overrated Amareleja still stays there.
I did contacted the COTR group (
http://www.cotr.pt/cotr_uk.asp), to get data from their stations (like Herdade dos Lameirões, Serpa, etc...), thought it are all located on plains, some could have get around the same as Amareleja or maybe a bit more (regarding summer values).
They say that information is private and only with money, people can get acess to it.
Well, I think that there are better ways to have this type of information.
I would like to know if that old Moura station, still gets temperature readings, the same for the one that´s close to Alcoutim and another one in Douro.
According to the IM estimations (which are calculated based on several aspects, such as temporary weather shelters that measure temperatures) the 3 months summer daily maximum average (1960-1990) was over 37ºc, in 2 regions (East Tagus and Douro Valley). In Douro (where it reached 37,5 in one location), more than one valley was calculated to surpass this value (37,0ºc).
In Guadiana it was about 35ºc, I think. For this case, I´m not sure how many places, according to this study got this value.
This is not 1 year record, is data for 30 years and the series is not particularly recent. This means that we would have to add something to these values, to have an idea how things work there nowadays.
The study was discussed before and I think that you maybe remember about it.
Now my opinion about this: I think that this study did opened the realistic hypothesis that the warmest areas (at least in continental Portugal) need to be in areas with low humidity on the air, very sheltered from winds, far from the sea influence (some places were over 200 kms from sea nearest point), in valleys or slopes (slopes get much higher minimum temps) located on a big continental mass (Iberia is big and low enough to generate its own heat even when the sea breeze hits the coast).
These areas aren´t studied, not even close to that.
But this study did located some the places that should be studied.
So, still a long way to go, to understand something about this humble country climatology.
Thanks for your patience and let´s hope to find something more.