Originally Posted by
RamvFrancisco,
Here is a link on Growing Degree Days: http://wine.wsu.edu/research-extension/weather/growing-degree-days/
This particular link refers to wine but it is applied to lots of things: apples, corn, tomatoes etc.
It is somewhat complicated to calculate GDD unless you have a spreadsheet with temperatures for all days in a year. But this website makes things very easy (atleast in most cities in US and Canada and even some major cities across the world)
http://www.wunderground.com. Enter the name of a city. Click on history and then the "custom" tab. Enter your begin and end dates. You can get historical temperatures, rainfall as well as a host of other values (including Growing Degree Days) for that location.
I have found this to be a very useful way to compare fruiting crop timelines across locations in the world.
Regards,
--Ram