Neue Probleme am Lugano Airport in Agno wegen Gegenwind (sorry, in German only)
Alarming, although somewhat strange note.
1st: Maximum take-off weight decreases with increasing air temperature (decreasing air density) and given runway length, but headwind shouldn’t actually be a problem and rather compensate for at least some of the temperature increase as the relevant figure is air speed, not ground speed.
2nd: I didn’t know Swiss Air Lines has Dash 8 planes. According to their web page, they don’t have any in their fleet as their only turboprops seem to be Saab 2000. Well, maybe they had to wet-lease some due to the new, tighter landing regulations for Lugano (AFAIK, the Saab 2000 have never been and still aren’t certified for the angle of attack the approach to LUG requires ). It looks like Flyaboo operates with DHC-8-300 Dash 8 however (unfortunately, I don’t have the world-wide plane immatriculation registry at hand, so I can only judge by comparing the pictures).
[UPDATE: CIRRUS Airlines carries out flights from Zurich to Lugano for Swiss (code sharing). They fly DHC-8-300 for that route indeed!]
3rd: In general, DeHavilland Dash planes are known to be pretty good for short runways. For example, the Dash 7 has a specified take-off distance (FAR25/ISA/sea level) of less than 700 m and a Vr (rotation speed) of less than 85 kts, making it an excellent STOL (short take-off and landing) plane. The DHC-8-300 Dash 8 doesn’t has STOL capabilities, but AFAIK it’s still a nice plane for rather short runways. It’s somewhat astonishing they’re having problems with the conditions in Lugano (I’d expect that when taking into account the level above sea level, a runway of 1340 m length should still be sufficient even at a slightly increased temperature, particularly in headwind conditions)
4th: It’s unlikely there have never been such weather conditions in previous years. Any indication that the security measures for take-offs from LUG have been tightened too?
Well, obviously these problems exist and I feel sympathy for Lugano which is experiencing a severe passenger drain (also for economical reasons though). I’m not a promoter of short-distance flights (I think a domestic and pan-european high-velocity metro similar to the unfortunately deferred swissmetro project would make more sense in every respect) but I understand the emotions of the people in Lugano and its surroundings. So far, there isn’t any alternative to planes for travelling fast.
 I remember an approach once to Lugano-Agno with a Metro III (then operated by Crossair) as a very scary experience. It has probably been the scariest approach ever for me as a passenger (extreme attack angle for that plane, stormy weather, plane shaking like hell), only followed by an approach to Maui (Hawaiian Airlines, MD-81, hot temperature, steep descent and curves you wouldn’t want to fly without excellent knowledge of the plane’s capabilities and local weather conditions. I really feared a sudden stall), one to Auckland (Air New Zealand, B747-200, miserable weather and turbulence during night) and an emergency landing once in Geneva (Swissair, DC-10-30ER, failure of engine 1 shortly after take-off. It was all under control, but an engine power loss during climb (frightening bang when it was switched off without prior announcement) and an emergency landing aren’t things you want to experience ;). BTW. Some amazing pictures of great (and sometimes pretty scary, too) approaches can be found at the airliners.net top-list.
[ADDENDUM: The cited news agency report is an example of misleading journalism. Regarding wind conditions, the emphasis should have been on “north wind”, not on “headwind”. “North wind” means that departing flights will use runway 01 (heading north 10°) instead of runway 19 (opposite direction). In this case, the most critical figure is the required climbing rate. For illustration, take a look at the following pics of runway 01: pic1, pic2. BTW The Keystone picture is misleading too as it pictures a A321/320/319/318 ;) FOCA Press release about recent procedures for LUG.]
[ADDENDUM2: NZZ makes the same mistakes, though they at least mention that these weather conditions aren’t a new thing]