January is one of Portland’s coldest months with an average low temperature of 36°F (2°C). Although it is the middle of winter, Portland does not experience much snowfall. Rain, however, is frequent with the city averaging 5 inches (124 mm) of rainfall. Average high temperatures are 47°F (8°C).
In February, temperatures increase slightly to average highs of 51°F (11°C). Low temperatures remain consistent with the previous month. February is the month with the most snowfall of 2 inches (5 cm).
March is the last month of Portland’s winter and signifies the start of the temperature’s steady climb upward. High temperatures are 57°F (14°C). Snowfall stops completely.
Portland weather in April: As spring settles in Portland, average high temperatures begin to breach the 60s in April. This is the best time to visit gardens and arboretums in Portland as the winter rains lessen considerably and turn into light spring showers. Average high temperatures reach 61°F (16°C).
In May, high temperatures hover at about 68°F (20°C) while low temperatures can fall to 49°F (9°C).
June brings temperatures in the mid 70s with approach of summer. Precipitation decreases to 2 inches (43 mm), meaning less rain, but not necessarily more sunshine. Average highs and lows range between 74°F (23°C) and 54°F (12°C).
July is one of the warmest and driest months in Portland. Average high temperatures can climb to 81°F (58°C) and precipitation drops to just under 1 inch (17mm). This is the ideal time to start planning outdoor activities and summer barbecues.
Portland weather in August: Temperatures and precipitation levels remain exactly the same in August, tying with July as the warmest and driest month in Portland. The nearly non-existent rainfall makes it a great time to explore the city’s forests, beaches, and rivers.
In September, temperatures start to cool again as average highs fall to 76°F (24°C). Rain showers increase in frequency to an average precipitation rate of 2 inches (37 mm) signaling the end of summer. Average low temperatures in September are 53°F (12°C).
October brings even more rain to Portland, increasing the precipitation average to 3 inches (76 mm). With the fall season underway, average high temperatures continue a steady decrease to the mid 60s.
November is the rainiest month in Portland with 6 inches (143 mm) of average rainfall. Temperatures decrease even further. Low temperatures fall to 40°F (5°C). High temperatures average 53°F (12°C).
In December, short bouts of snowfall arrive for the coldest month in Portland. Despite being the coldest month all year, Portland’s winters are not too extreme with average low temperatures of 35°F (2°C) and average high temperatures of 46°F (8°C).
Best months for day trips to Oregon’s waterfalls and to experience other gorgeous sights and landscapes are July and August. The summer months are also the best time to see Oregon’s Painted Hills and the John Day Fossil Beds National Monument. Despite the frequent showers, spring is largely regarded by locals as the best time to visit vineyards and to the large crowds of summer.