Oregon lies in the Pacific Northwest region and has a diverse geography that consists of numerous water bodies, deserts, shrublands, dense forests, mountains, and volcanoes. California in the south, the Pacific Ocean in the west, Washington in the north, Idaho in the east, and Nevada in the southeast share borders with the state. Western Oregon along the coast has an oceanic climate (Köppen climate classification Cfb) with wet summers, while the southwestern portion of the state has a Mediterranean (Köppen Csb) climate with hot summers; The northeastern portion has a steppe climate with subarctic (Köppen Dsc) conditions at high altitude, and the rest of the east is semi-arid (Köppen BSk) with cold and snowy winters. The Pacific Ocean has a significant influence on the climate that keeps the temperatures mild in comparison with places at similar latitudes.
Oregon, the Beaver State's topography ranges from rain forests along the western coast to semi-arid conditions in the central and southeastern regions. Mount Hood is the highest peak in the state, while Columbia is the most important river that flows through the Cascade Mountains. The three mountain ranges: Coast, Cascade, and the Blue Mountains influence the climate in the parts of the state that lie in their proximity. The river valleys have the most fertile agricultural lands, while mountains and plateaus provide for dry farming and livestock grazing. The arid Columbia plateau covers two-thirds of the total area of the state with elevations ranging from 1500 to 2000 meters.
Oregon registers wide variation in temperatures across four seasons. Summer high temperatures average 64°F (17.8°C) to 68°F (20°C) in July on the west coast, while they range between 81°F (27.2°C) to 94°F (34.4°C) in the eastern portion of the state. The average low temperatures in the winter hit 18°F (-7.8°C) in January in the Cascade Mountains, while they register in the mild 37°F (2.8°C) to 42°F (5.6°C) range in the coastal region. Spring is mild and wet in many parts of the state except for places like Crater Lake, where the nights are below freezing. Autumn is pleasant and colorful, with day temperatures exceeding 55°F (12.8°C) in October.
Rainfall in Oregon varies considerably from the west coast to the central and eastern regions. The coast registers 80" (2032mm) to 90" (2286mm) of rain annually, which increases up to 200" (5080mm) on the western slopes of the Coast Range. The average precipitation on the plateau region is a mere 8" (203.2mm), while the eastern slopes of the mountains receive 15" (381mm) to 20" (508mm) of annual rainfall. Average annual snowfall ranges from 2" (50.8mm) along the coast to 12" (304.8mm) in the inland valleys. Central Oregon registers 20" (508mm) of snow, while the eastern portion records 55" (1397mm). The mountain ranges record a massive 150" (3810mm) to 550" (13970mm) of snow with the heaviest snowfall in the Cascade Mountains. Portland, the capital of Oregon, records 142 sunny days in the year.
Pendleton in Oregon recorded the highest ever temperature of 119°F (48.3°C) on August 10, 1898, while Seneca recorded the coldest temperature of -54°F (-47.8°C) on February 10, 1933.
The best time to visit Oregon
The best time to visit Oregon is during the summer from June to August when the weather is relatively dry. Wildflowers are in full bloom by July even in the upper reaches of the mountain ranges. Late spring has mild conditions, but the weather is unpredictable. Early autumn in September often has good weather along the coast. The Coast Range has a relatively mild climate due to the influence of the Pacific Ocean, while the central and eastern parts register temperatures above 100°F (37.8°C).
The worst time to visit Oregon
The worst time to visit Oregon is from December to February in the winter. Winter is snowy in the mountains, especially the high elevations of the Cascade, Blue and Wallowa mountains. The majority of the rainfall occurs from October to May with a peak during the cold season. Heavy and persistent snowfall results in significant snow depth that serves as a major attraction during the skiing season. Snowstorms frequently strike the mountains and may last more than 24 hours. Winter skies are gray with frequent blasts of arctic air.
Oregon is vulnerable to hailstorms, thunderstorms, wildfires, snowstorms, hurricanes, and floods. Hailstorms are common on the eastern side of the Cascade Mountains and cause damage to crops. Thunderstorms with lightning occur 10 to 15 days annually in the mountain areas with a heightened risk of forest fires. Hurricane-force winds strike the Oregon coast several times in the year, occasionally move inland and cause destruction of power lines. Flooding is frequent in late spring and summer in the Willamette and Columbia river basins due to rain and melting of snow. Snowstorms occur in winter in the high mountain ranges.
Weather in January
January is the coldest month of the year in Oregon with gray skies and abundant snowfall in the high mountains. The average low temperatures across the state are between 11°F (-11.7°C) to 42°F (5.6°C), while the average high temperatures lie in the 34°F (1.1°C) to 55°F (12.8°C) range. Portland, in the populated Willamette Valley, averages between 36°F (2.2°C) to 47°F (8.3°C). Seneca in eastern Oregon has freezing nights with the mercury column in the range of 11°F (-11.7°C) to 35°F (1.7°C). Precipitation is heavy along the coast and the mountains where it crosses 11" (279.4mm) in many places. Heavy snowfall in the Cascade and the Blue Mountains surpasses 25" (635mm) at altitudes above 1500 meters. Arctic winds create icy conditions in the state except for the coast, where the Coastal Range acts as a barrier. January is usually an off-season for tourism, but visitors find eastern Oregon as well as the coast relatively warmer and inviting than the rest of the state. Pack in layers while visiting cold areas to enjoy the skiing season.
Weather in February
February is chilly in Oregon as the winter brings cold winds along with precipitation and snowfall to the state. Day temperatures are above freezing and remain in the range of 35°F (1.7°C) to 55°F (12.8°C) with rare extreme weather except for occasional snowstorms at high altitudes. Nights are bitter in the central and eastern parts, where they routinely dip below 25°F (-3.9°C). The Columbia plateau barely experiences 2" (50.8mm) of precipitation on an average, while the coastal areas such as Gold Beach receive 10.3" (261.6mm) of rainfall. Snowfall is persistent in the mountains, with Crater Lake Park receiving at least 70" (1778mm) in February. Visitors find the beautiful ski-trails and Nordic adventures to their liking in places such as Bend, on the eastern edge of the Cascade Range. Sunny days and bright skies are at a premium in February in Oregon. Days are short, and the sunshine is mild at best during afternoons. Pack warm winter clothes even for places that are relatively warmer than the cold mountain slopes.
Weather in March
March is cold in Oregon as the state tries to free itself from the clutches of the winter. The icy roads thaw steadily under the influence of the warm sunshine. The average temperatures across the state range from a freezing 19°F (-7.2°C) in the Cascades to a warm 57°F (13.9°C) along the coastal regions. Day highs in Pendleton in the northeast reach 55°F (12.8°C), while nightly lows at Lakeview in the Cascade Mountains drop to a chilly 27°F (-2.8°C). Cold fronts are frequent during the early part of spring as frost fingers linger on the windows and roofs of buildings. March sees plenty of rain to the tune of 8" (203.2mm) to 10" (254mm) in the coastal towns and cities, while the central and eastern regions remain relatively dry. Snowfall is absent in the Willamette Valley, but the mountains register plenty of snow. Many places across the state record at least 10 to 12 sunny days in the month. Dress in layers in the mountains, and carry an umbrella or rain jacket in coastal regions of Oregon in March.
Weather in April
April welcomes the beautiful spring season to Oregon with its mild weather that spreads a blanket of greenery over the landscape. The average high temperatures range from 53°F (11.7°C) to 62°F (16.7°C), while the low temperatures average between 23°F (-5°C) to 43°F (6.1°C). Day temperatures are in the comfortable zone in most of the state, barring the higher mountain slopes which remain below freezing. Snowfall ceases everywhere by April except for the upper slopes of the mountain ranges where it ranges from 10" (254mm) to 40" (1016mm). The region east of the Cascades receives scanty rainfall, while it is wet on the western side and the coast. The snow thaws by mid-April in the lower areas and is absent on the Columbia plateau. Burns, in southeastern Oregon, registers 15 sunny days in April. The explosion of pink cherry blossoms brings many visitors to the Portland and Hood River region in April. The flowering trees and wild trilliums provide a scenic habitat to the singing birds. April brings a change of seasons in Oregon as the days turn from cold to warm.
Weather in May
May is a warm spring month with many sunny days amid bright skies in Oregon. The average high temperatures in the state are in the pleasant 49°F (9.4°C) to 75°F (23.9°C) range, while the average low temperatures are in the mild 28°F (-2.2°C) to 46°F (7.8°C). Astoria, on the coast, averages between 46°F (7.8°C) to 60°F (15.6°C), while Ontario in the east registers the warmest, between 44°F (6.7°C) to 75°F (23.9°C). Rainfall is a moderate 1" (25.4mm) to 5" (127mm), with a marked decrease even in the coastal areas. Willamette Valley sees 12 to 14 sunny days, while eastern Oregon records 15 to 18 days of bright sunshine in May. The fresh air brings a wealth of flora and fauna to the fore. The steady melting of snow brings plenty of freshwater to the lakes and rivers. Depoe Bay is the best place for whale watching, but keep in mind that the peak period of whales passing the Oregon coast wanes by the end of May. Keep an eye on thunderstorms in May, especially in the mountains of Oregon.
Weather in June
June is the beginning of the summer in Oregon that sees a significant rise in heat and humidity. Day temperatures are in the range of 58°F (14.4°C) to 84°F (28.9°C), while nights record between 33°F (0.6°C) to 52°F (11.1°C) across the state. Salem in the north registers mild average temperatures between 49°F (9.4°C) to 74°F (23.3°C), while Medford in the south is in the warm 52°F (11.1°C) to 82°F (27.8°C) range. June has an average of 18 days of bright sunshine. Humidity is between 60% and 80% in many places, but the rainfall is light and rarely crosses an average of 2" (50.8mm) in the state. Witnessing surging waterfalls that roar mightily creates a sense of adventure as does the primeval cedar forests in the warmth of summer. Camping, fishing, and boating activities attract locals and tourists alike. Light sweaters are useful in the evenings in the mountains, while sweatshirts fare better in the afternoons on the plains. June begins the peak season for tourism in Oregon.
Weather in July
July is usually the hottest and sunniest month of the year in Oregon. The average high temperatures across the state are between 64°F (17.8°C) to 94°F (34.4°C) with many cities in the range of 85°F (29.4°C) to 90°F (32.2°C). Ontario, on the eastern border, registers many days above 100°F (37.8°C). The conditions are scorching hot in the High desert region, where it is better to spend afternoons in the shade. The days are sunny and bright everywhere, and the skies are blue and clear. Solar radiation is at its peak during July. Humidity decreases when moving from the coast to the east. Peak summer is the height of the tourist season with a multitude of outdoor activities like camping, fishing, swimming, biking, and trailing. Light summer clothing is suitable on the plains during the day, while a light sweater makes the nights comfortable in the highlands. July is dry in the majority of Oregon, but thunderstorms with lightning occur periodically.
Weather in August
August is a hot summer month in Oregon with sunny days and clear skies. The arid lands in the central and eastern parts experience vast temperature differences of 35°F (1.7°C) to 40°F (4.4°C) between day and night. Willamette Valley has mild temperatures that often remain below 80°F (26.7°C). The average high temperatures statewide are in the warm to hot 65°F (18.3°C) to 92°F (33.3°C) range with an average of 23 sunny days. Humidity is high in the coastal areas, particularly in the morning, when it reaches 80% and above. August nights are perfect for camping and stargazing with negligible rain and clear skies. Light summer clothing works well, but long pants are better while traversing forested areas. August provides excellent conditions for hiking the panoramic trails and mystic waterfalls such as those near the Columbia River Gorge. Wildflowers bloom in the natural habitats and rivers roar with abundant freshwater. Watch out for wildfires in the dry forest areas during August in Oregon.
Weather in September
September has comfortable conditions in Oregon with the arrival of the fall season. The weather is pleasant, and light breezes make the evenings enjoyable near the coast. The autumn wears a colorful cloak, which grows in beauty by the third week of September. The temperatures are moderate, with the majority of the state registering average high temperatures below 85°F (29.4°C). Toketee Falls in the Cascade Mountains is in the 45°F (7.2°C) to 75°F (23.9°C) range, while Summer Lake in eastern Oregon registers between 43°F (6.1°C) to 79°F (26.1°C). Early fall sees an uptick in rainfall with an average of 2" (50.8mm) to 4" (101.6mm) across the state. The skies are bright with at least 20 sunny days in the month. Mountain trails remain open, but crowds are fewer compared to the peak tourist season. September is an excellent time to experience the majestic beauty of the state amid moderate weather. Many locals describe fall as their favorite season in Oregon. Wear a light jacket to encounter the breezy fall evenings.
Weather in October
October is the time for peak fall foliage in Oregon as the state braces for a drop in night temperatures. The average high temperatures are comfortably warm in the 55°F (12.8°C) to 70°F (21.1°C) range, but the nights are cold with the average low temperatures in the 32°F (0°C) to 48°F (8.9°C) range. The coastal areas offer gorgeous warm days at the beach, but the Cascades may see the first flurry of snow. The skies are partly cloudy as the state witnesses an average of 18 sunny days in the month. Precipitation increases significantly as the beginning of the wet season brings 5" (127mm) to 7" (177.8mm) of rainfall along the coast. Cedars, maples, and willows display peak colors from orange, red, purple, yellow, to gold by mid-October. Traversing the scenic bikeways, motorways, and waterways is the best way to experience the colors. Dress in layers as cold winds routinely blow in the evenings during October in Oregon.
Weather in November
November ends the beautiful fall season in Oregon to push it into the arms of winter. Day temperatures are in the average range of 46°F (7.8°C) to 57°F (13.9°C), but the nights are below freezing in many places as they register in the 27°F (-2.8°C) to 45°F (7.2°C) zone. Places like Seaside and Tillamook on the coast average between 40°F (4.4°C) to 56°F (13.3°C), while Heppner and WhiteHouse Ranch in the east remain in the 27°F (-2.8°C) to 51°F (10.6°C). The wet season advances in the state as many places on the west side of the Cascade Mountains receive at least 10" (254mm) of rainfall. Snowfall is ample in the mountains, with an average of 15" (381mm) to 20" (508mm) in the Cascades. Cold fronts frequently invade the state and cause a significant dip in temperatures. The short days see a sharp drop in the sunshine as the skies remain partly cloudy for the majority of the time. Tourist numbers drop by late autumn, and it is an excellent idea to bid goodbye to Oregon by the end of November.
Weather in December
December brings the cold winter to Oregon with the average high temperatures in the 35°F (1.7°C) to 55°F (12.8°C) range and the average low temperatures in the chilly 11°F (-11.7°C) to 42°F (5.6°C) range across the state. Cold air masses move through the high mountain passes and settle along the valley floors. The average temperatures in Newport on the coast are in the mild 40°F (4.4°C) to 51°F (10.6°C) range, while Klamath Falls is cold between 22°F (-5.6°C) to 42°F (5.6°C). December brings heavy rainfall in Oregon, with a high of 14.5" (368.3mm) at Brookings, on the coast. The mountains record heavy snowfall, often to the tune of 25" (635mm) in December, but the west side of the Cascades receives a meager amount of snow. The skies are bleak as rain, ice, and snow routinely hit the landscape. Oregon has numerous ski resorts, and snowshoeing is a popular activity in the winter. Overall, it is better to avoid Oregon in December unless tourists want to visit the mild southeastern part of the state.