Have you checked my links ?
I do not have any personally acquired data yet, I plan to buy a good weather station the day I definitively move here.
Best I can say is : have a look at the links I previously posted as well as on this this one witch has a history (link on left side of the page) of several year, the official Portuguese weather service (open "climate" - on top of the page) also has some good info with publicly available graphics, analysis, maps, anomaly, averages etc.
I think I can say that Faro and VRS Antonio (east of Faro, on the Spanish border) is the warmest part, that's also my personal observation and what local people say. West Algarve (from Sagres and up north) is not as warm but is still nice.
One more thing, I'm originally from Switzerland and plan to move here because of climate (and my Portuguese wife :% ). We had enough of Swiss winters around Geneva (+/- 11 months/year... :o ) and we were looking for the warmest part/best possible climate in Europe to settle down, think we found the right spot here (in Almancil, close to Faro).
Final thoughts, it's fine here as long as you speak decent Portuguese, closely connect with the locals and "aren't too obviously from the UK". In private most locals acknowledge they really don't like Brits too much around here... They say there are too much of them who absolutely do refuse to integrate/learn Portuguese, try to exploit locals etc... Must say it's not completely wrong... :%
Don't hesitate to ask if you guy's think I can help any further.