Seasonal Anxiety:

       This link is a good read for the many people who deal with anxiety issues- which includes myself: http://voices.yahoo.com/winter-season-exacerbates-anxiety-panic-attacks-4756712.html I brought up seasonal depression in an older post, but I also want to bring up seasonal anxiety and also panic attacks. (Which are commonly confused with generalized anxiety.) Not everyone hates winter but many people do. The fastest growing regions of the US in the past decades have been in mild climate regions. Few people enjoy being cold or driving in the snow but there are other things that can make Winter depressing such as the amount of daylight and other things no one can seem to put their finger on. Winter seems to be a season where one can feel claustrophobic and agoraphobic at the same time. Luckily where I live, this winter has been milder than average and almost "European" in it's feel, but it is still Winter and this is still northeastern Pennsylvania. Other years we are not so lucky. Another odd thing with Winter is that while most illnesses seem to peak in the colder months, it seems that this occurs in areas with warm Winters as well as colder areas. Flu season is flu season whether one is in Miami, Minneapolis, or Moscow. As far as anxiety there seem to be many things that come together in the Winter to aggravate things, but a lot of it seems to boil down to the feeling of less control over one's environment which the article I linked to above seems to get at.
For more background on Panic Attacks read this: http://www.diagnose-me.com/cond/C345710.html
As for Claustrophobia (which involves more than people think): http://www.pe2000.com/pho-claustro.htm
And Agoraphobia: http://www.adaa.org/understanding-anxiety/panic-disorder-agoraphobia