Weather in Italy: I can find temperature--what about seasons?

May is the greenest landscape, if you like spring colors it's the best time to go. October is when you see beautiful Autumn colors in Florence. September might be too early for Fall colors. It's generally still green, getting yellowish toward the second half of September. But you said you want to see green, therefore May is the number one month, long days too as sunset is later. My favorite month in Tuscany, where I grew up.

Italy is alway green. I've never seen it brown. I've been there as late as December and it's still green.

Italy is green in September. Whether you go there in May or September, Italy is green.

Hi Nancy
I thought I would share a link that I've used when planning a trip to Italy that might offer answers to the concerns you mentioned in your posting.

http://goitaly.about.com/od/whentogotoitaly/a/spring.htm

All of our travel to Europe (Italy, Scotland, England and Normandy and Provence in France) has been in mid to late September and we found the weather to be terrific except in the UK. Highs in Florence and the Cinque Terre were low to mid 60s and in Rome in the low 70s. I'm told that Spring over there is also nice, but keep in mind that if you compare where Italy is geographically compared to places in the US it will give you an idea when Spring might arrive there. Rome, for example, is 42 degrees latitude, just about the same as Boston, so you can probably calculate the Italian weather and foliage based on that. FYI, I'm planning my first solo trip to Italy (all others have been family) at the beginning of May and expect it will be a bit chilly, but I prefer that over the heat of summer. Hope this helps.
Jim

This is TUSCANY in May.
http://magazine.voiaganto.it/wp-galleryo/toscana-bellissima/campagnatoscana2.jpg

This is late September:
http://www.arcicaccia.it/wp-content/uploads/2013/10/toscana.jpg

Later in October
http://static.panoramio.com/photos/large/44761420.jpg

Comparing latitudes between Europe and North America does not make much sense. At the same latitudes Western Europe has milder weather. This is due to the fact that most of Western Europe is never too far from the mitigating effects of the seas. in particular the warm Mediterranean. Whereas much of North America has continental weather like Russia.
Also Western Europe benefits from the effects of the Gulf Stream. Therefore comparing, Western Europe with Canada, Illinois with Italy, or France with Alberta, even though at the same latitudes will not yield similar results. Winter in Chicago is much colder than Rome, although at the same latitudes.
Italy has weather similar to Northern California. Northern Italy is more like Oregon, albeit less rainy. The west coast is as far as you can use latitude for comparison.

Sacramento, California is green in January. I was just there.

I have never seen Autumn colors like we have here in the Midwest amd East coast in Italy.

Begging to differ with Sandra, Italy is not always green. It's not Hawaii. The first time we went to Italy was September 2003 and it was very brown after a long hot summer. However it is always green in spring. And you get flowers. All our subsequent trips have been in May. The only risk then is it's more likely to rain. But the longer days make up for that, imho.

I also beg to differ with Sandra. Italy does have Fall colors.

The picture below was taken at the end of October 2010 near Pistoia in Tuscany.
http://farm2.static.flickr.com/1390/5145811273_1ccba0817f_m.jpg

Sacramento also has Fall colors, generally in November. I know because I work there every November.

When I drove through Tuscany and Umbria the first half of last October, I was struck by how green both trees and vineyards still were. It was much closer to Robert's late September photo than his late October photo. Many non-vineyard fields, however, had been freshly plowed under.