Portland Weather In May
The highest recorded temperature in May for Portland for the past 70 years was 100 degrees Fahrenheit, most recently measured on May 28, 1983, and the normal high is 67. The lowest reported temperature in May for Portland for the past 70 years was 29 most recently registered on May 1, 1954, and the normal low daily temperature is 48.
United States NWS historical Portland May Weather data records that on May 3, 1952, the high temperature did not exceed 60 degrees Fahrenheit, the lowest high measured in Portland in the past 70 years. Weather Service records additionally indicate that on May 31, 1986, the low for the day was not measured below 62 degrees, the highest low temperature recorded in Portland in the last 70 years.
Weather Service historical data shows that the average daily high temperature in Portland on May First is 44 degrees Fahrenheit and the average high on the last day of May is 39 degrees. The daily low temperature in Portland on May First averages 32 degrees Fahrenheit and the low on the last day of May averages 27 degrees.
Portland usually receives an average of 2.38 inches of precipitation during May. The most rain recorded in a single day, as shown by May Portland Weather data, was 10.28 inches on May 30, 1956.