As we transition from season to season, it is important to remember that moving from a warm atmosphere into a cool one and vis-versa has a detrimental effect on the chanter reed. It affects the whole pipe, but I’ll focus on the chanter reed.
Warm, humid climates, cause the reed to open up and become flatter. Conversely, a cooler, dryer climate will cause the reed to close which raises the pitch. For this reason, it is essential to warm up in the same climate in which you are to play. If you warm up indoors in an air conditioned space and walk outside to play in the heat of the day, your pipes will blow widely out of tune very quickly. The converse is true obviously.