The fighting season in Afghanistan typically starts in the spring and ends in the fall. Insurgent activity does not end completely; it just subsides significantly (somewhere around 30 to 60 %). The Afghan National Security Forces (army and police) usually take the winter time to do some re-training, re-fitting, leave time, and re-organization; although 2012 and 2013 saw some ANSF activity to "shape" the battlefield for the summer fighting seasons. This past fighting season (2014) is easing up; the activity level will go down as we move into November. Both the Taliban and the ANSF (along with ISAF) conduct a review of what worked and what didn't work. Once the fighting season assessments are completed, then they adapt their training and preparations for the upcoming fighting season (2015). One analyst, Jason Lyall, has identified five trends and lessons of the 2014 fighting season. Jason is an Associate Professor of Political Science at Yale University and his work examines wartime dynamics of violence and insurgencies.
1. The ANSF suffered highest loss rates of war in 2014.
2. Taliban massed on the battlefield with operations against 41 districts.
3. Taliban now has capability to conduct operations across the entire country.
4. Pakistan's aid to the Taliban continues and may have increased.
5. Intensity of fight forced ISAF to use its dwindling air power.
You can read his entire analysis of these five trends in "A (fighting) season to remember in Afghanistan", The Washington Post, October 20, 2014.