Planning for the weather is an important factor for making your trip to Nahuel Huapi National Park a success, especially when you're splurging. The hottest months are usually January and February, with an average temperature of 11°C, while the coldest months are July and August, with an average of 1°C. The rainiest months in Nahuel Huapi National Park are June, August, July and May, with each month seeing an average of 257 mm of rainfall.