Other forms: phenologists
A phenologist is a scientist who specializes in seasonal cycles. Phenologists study the way things like birds' migratory patterns change from year to year along with variations in weather and climate.
If you carefully document the differences in the ways leaves change every autumn — brilliantly colored one year, duller the next — you can consider yourself an amateur phenologist. These biologists focus on observing patterns and changes in natural cycles, including things like when plants bloom in the spring and which butterflies emerge each summer. Phenologists pay particular attention to how a warming climate affects these phenomena. Phenologist is derived from a Greek root that means "bring to light."