A combination of tropical location and high altitude ensures the most of Rwanda has a temperate year-round climate. Temperatures rarely stray above 30 degrees Celsius by day or below 15 degrees at night throughout the year. The exceptions are the chilly upper slopes of the Virunga Mountains, and the hot low-lying Tanzania border area protected in Akagera National Park. Throughout the country, seasonal variations in temperature are relatively insignificant. Most parts of the country receive in excess of 1,000mm of precipitation annually, with the driest months being July to September.