H.contortus survives in warm and moist conditions. Transmission periods are usually considered to be between 15-37 ◦C (Van Wyke and Reynecke 2011). The R0 model predicts when climate is going to be suitable for parasite transmission.
As reflected in the R0 graph the wet season is between November to April with the dry season occurring for the rest of the year.Most of Zambias landmass is considered temperate however there are large portions of tropical climate zones throughout the country. There is also an arid steppe zone along the southern border of the country.