Take this into consideration too. :thumbsup:

Change in photoperiod is the factor that usually triggers the developmental stages of Cannabis. Photoperiod and seasonal cycles are determined by latitude. The most even photoperiods and mildest seasonal variations are found near the equator, and the most widely fluctuating photoperiods and most radical seasonal variations are found in polar and high altitude locations. Areas in intermediate latitudes show more pronounced seasonal variation depending on their distance from the equator or height in altitude. A graph of light cycles based on latitude is helpful in exploring the maturation and cycles of Cannabis from various latitudes and the genetic adaptations of strains to their native environments.

The wavy lines follow the changes in photoperiod (daylength) for two years at various latitudes. Follow, for example, the photoperiod for 400 north latitude (Northern California) which begins along the left-hand margin with a 15-hour photoperiod on June 21 (summer solstice). As the months progress to the right, the days get shorter and the line representing photoperiod slopes downward. During July the daylength decreases to 14 hours and Cannabis plants begin to flower and produce THC. (Increased THC production is represented by an increase in the size of the dots along the line of photoperiod.) As the days get shorter the plants flower more profusely and produce more THC until a peak period is reached during October and November. After this time the photoperiod drops below 10 hours and THC production slows. High-THC plants may continue to develop until the winter solstice (shortest day of the year, around December 21) if they are protected from frost. At this point a new vegetative light cycle starts and THC production ceases. New seedlings are planted when the days begin to get long (12-14 hours) and warm from March to May. Farther north at 600 latitude the day-length changes more radically and the growing season is shorter. These conditions do not favor THC production.

Marijuana Botany - Chapter 4 - Maturation and Harvesting of Cannabis