peru's average climate range in january is 21c to 10c in june. in the summers its hot and humid with showers in the afternoons lows between 18 and 22 °C (64.4 and 71.6 °F) and highs are between 24 and 29 °C (75.2 and 84.2 °F). the lowest the TEMPERATURE dropped in the winter is -24c. On the coast winter lasts from June to September. It hardly ever rains in Lima nor most of the coast, except for Tumbes and Piura, which have tropical climates.During June to September, the mountainous areas are often sunny during the day but cold at night. Heavy rains in the mountains and jungle last from December to April. It is rainy and hot for most of the year, but between March and September there are occasional cold surges which might require a jumper.