The influence of temperature on oviposition behavior, adult longevity, and fecundity on two Norwegian populations of the codling moth, Cydia pomonella (L.), was investigated within the range of 12.3–25°C. In addition, lower threshold temperatures (T₀) and degree-day (DD) requirements for three egg developmental stages are given. The results showed that the Norwegian populations of C. pomonella lay eggs at lower temperatures than reported previously from other countries. Eggs were deposited in ≈40% of the containers at an average temperature of 12.3°C. However, below 15°C, <40% of the population deposited eggs that developed to the black head stage. Preoviposition period was highly affected by temperature, and it was the only response for which population (West versus East) had a significant effect. At lower temperatures (≤15°C), the preoviposition period was markedly prolonged in both populations. The western population required ≈20 DDs more than the eastern population at a base temperature of 11°C, but these results remain to be validated with field data. Temperature had no significant effect on the realized fecundity per ovipositing female or the fertility of these eggs, and both responses were highly variable at all temperatures investigated. Mean fecundity was 11 eggs per female. All estimates of T₀ for the egg developmental stages were below 10°C, which suggests that the base temperature for egg development for the Norwegian populations of the codling moth is 1 or 2 degrees lower than 10°C.