The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.