A quick tip for Scrum Masters as we head into the summer months. You may have recognized this in the past but the allure of sunshine and warm weather can impact the productivity of your team.
A study by Captivate Network of 600 workers reveal a 20% decrease in productivity during the summer. There are many reasons for this and the study indicates a few of them. Between long lunches, leaving a little early on some days, and company outings this does make sense. After the crazy winter we’ve had in the Midwest, we are all feeling the need to venture outside and enjoy the sunshine.
If you are sensing a productivity lag with your teams, here are a few things to consider:
Adjust your planning velocity. Reduce the velocity used to determine how many stories the team will commit to during a sprint. I call this the “summer velocity.” I have used a 25% reduction in the past and it seems to be about right but tweak as necessary. If the team finishes their sprint stories early, the team can always pull stories in from the backlog. By adjusting the velocity, the frustration of participating in a sprint review with unfinished stories and nothing to demonstrate is removed.
Establish realistic expectations. If you have a major release planned for later in the summer, prepare the organization for variability. If possible, Mike Cohn recommends planning slack by using feature and schedule buffers. Feature buffers inform the organization which features may not be completed by the release date while schedule buffers are created by adding a period of time to reflect uncertainty. 
Amplify productivity cycles. As you observe your team, you may begin to notice segments of the day when they are more productive than others. Some teams work well in the morning while others don’t really get going until noon. When you have identified the productivity cycle of your team, make the best use of this time but clearing anything that could interrupt them or cause a loss of focus and energy. Perhaps meetings or team social activities can be shifted to non-productive cycles.
Enjoy the summer everyone!
 Cohn, Mike (2006). Agile Estimating and Planning (pg. 188-189) Prentice Hall.