Summers in Portland are warm, dry, and sunny, though the sunny warm weather is short lived from mid June through early September. The months of June, July, August and September account for a combined of total rainfall only 11% of the of the precipitation that falls throughout the year. The warmest month is August, with an average high temperature of . Because of its inland location from the coast, as well as the protective nature of the Oregon Coast Range to its west, Portland summers are less susceptible to the moderating influence of the nearby Pacific Ocean. Consequently, Portland experiences heat waves on rare occasion, with temperatures rising into the for a few days. However, on average, temperatures reach or exceed on only 61 days per year, of which 15 days will reach and only 1.3 days will reach . The most 90-degree days ever recorded in one year is 31, which happened recently in 2018. The highest temperature ever recorded was , on July 30, 1965, as well as August 8 and 10, 1981. The warmest recorded overnight low was on July 28, 2009. A temperature of has been recorded in all five months from May through September.