As the province is mostly mountainous, it experiences a dry cold climate from October to March, while the tropical monsoon is rainy season which lasts from April to September. The annual average temperature is 23 °C (73 °F). The temperature generally ranges between18 °C (64 °F) and 28 °C (82 °F) in the mountainous region, with the lowland areas showing a temperature variation of between 20 °C (68 °F) and 22 °C (72 °F). In Sapa town however, the temperature drops to less than 0 °C (32 °F) with snowing conditions. Fog and frost are a common phenomenon in the province.