Is there a reason why I might get kidney stones at the same time every year?

Yes. Most people who develop kidney stones around the same time every year is usually during the summer time when the temperature is hotter. This is when people do not drink enough fluids and become dehydrated and/or get concentrated urine which will increase chances of forming kidney stones. Also, a poor kidney stone diet during this time period will also increase chances of forming stones.
Summer stones ? Is it during the summer or during months where u may be more dehydrated? Does your diet change at all during those months?

Related Questions

Any reason why I would get kidney stones at about the same time every year?

Cyclic stones. Probably due to environmental/exertional and lifestyle changes that occur throughout the year - more active/need more fluid intake, warmer(colder) weather/need more fluid intake, different diet (more salt in summer months/need more fluid 9and decrease sodium intake). Read more...