What is the weather like in Florence?

What is the weather like in Florence? This is one of the commonest questions students keep asking me, and one of the most difficult indeed. I know that the weather question is a main topic in every country, mostly used to start up a conversation. But students are normally concerned with the weather before leaving their country because they need to pack up and choose the clothes to carry with them. My answer is always to put a bit of everything in the suitcases, since the weather in Florence can be either terribly nasty or surprisingly lovely. If we exclude the month of July, whose temperatures have always been above 30 degrees (yes, we only use centigrade in Italy) since the last ice age, and the months of December and January, which are as chilly and freezing as in most of Europe, the other months often like to joke around with the climate. No doubt that the greenhouse effect is one of the main causes of these erratic changes, but I think that are few places around the world that you can find 5 degrees in the morning and 25 in the afternoon, lots of rain or the so-longed-for sunshine. The first result of these whimsical changes is that many students catch a cold: when in the morning they see the sun from the window, they probably think of the famous song “o sole mio”, they just wear a t-shirt and a pair of flip-flops although at 8 am there are only 5 degrees and in a couple of days they go to the doctor with their health insurance (non-UE students must get one before departing from home or buy one when in Italy).
My advice is to do like the italians do: get dressed like an onion (“a cipolla”), that is with different layers of clothing: for instance a t-shirt under a jumper and a jumper under a jacket. During the day you take some of your outfit off according to the temperature. However, needless to say that “cold” and “hot” are often very subjective adjectives. I have met a sixty-year old Norwegian lady who wanted to convince me to bathe in the sea in February (don’t do that!) or an American girl who constantly turned on the air-conditioning during April. In Italy we have an old saying for April which is “aprile non ti svestire”, which means: in April do not get undressed, but which can also make you realize that clothes are definitely the best air-conditioner. I guess the kyoto protocol supporters should take this into account.