Portland, Oregon is known for its unique and varied climate. Summers are short, warm, and mostly clear, with temperatures often reaching up to 84°F.
In contrast, winters are very cold, wet, and overcast, with temperatures frequently dropping to 36°F.
Portland experiences an average temperature range from 36°F to 84°F throughout the year, and it is rarely below 26°F or above 95°F.
Located about 7 miles from Portland, the Portland International Airport provides comprehensive climate data.
Annual weather patterns indicate significant rainfall during the colder months, particularly between November and March. This makes Portland one of the wettest urban areas in the state of Oregon.
The varied weather conditions make each season distinct and impactful on daily life and activities.
Summers are characterized by their dry and warm nature, while the winter months bring considerable rainfall and overcast skies.
For those considering visiting or moving to Portland, understanding these climate patterns is essential for planning activities and daily routines.
Average Temperature in Portland, Oregon
Portland, Oregon experiences varying temperatures throughout the year.
The cold season lasts from mid-November to late February, with an average daily high below 52°F. January is often the coldest month, with nights dipping to around 37°F.
In contrast, the warm season runs from June through early September.
July is typically the hottest month, with average highs of 78°F and lows around 61°F. August also sees warm temperatures, often reaching 83°F during the day and dropping to 57°F at night.
Below is a summary of average temperatures:
| Month | High (°F) | Low (°F) |
|---|---|---|
| January | 46 | 37 |
| February | 48 | 37 |
| March | 54 | 41 |
| April | 60 | 45 |
| May | 67 | 51 |
| June | 72 | 56 |
| July | 78 | 61 |
| August | 83 | 57 |
| September | 75 | 53 |
| October | 63 | 46 |
| November | 52 | 39 |
| December | 46 | 37 |
Portland’s temperatures show significant seasonal variation, providing a mix of warm and cool periods.
For instance, average high temperatures in June start to rise, leading to the peak warmth of July and August.
Winter months often bring cooler temperatures, especially in January and February.
Despite the cold, Portland does not typically experience severe freezing conditions, making it favorable for those who prefer milder winters.
Average Precipitation in Portland, Oregon
Portland experiences varying levels of rainfall and occasional snowfall throughout the year, which contribute to the lush, green landscape the city is known for.
Average Rainfall in Portland, Oregon
Portland receives an average of 36 inches of rain annually, with the wettest months occurring from November to March.
These months see the most significant rainfall, often leading to wetter conditions and cloudy skies.
November typically experiences the highest monthly rainfall, averaging around 5.5 inches.
The summer months, particularly July and August, see much less rainfall, often below 1 inch, making them the driest months of the year.
Rainfall is frequent, with an average of 155 wet days per year. This gives Portland its reputation for being a rainy city, especially in the fall and winter seasons. The consistent rain helps maintain the city’s green spaces and gardens.
Average Snow in Portland, Oregon
Snowfall in Portland is relatively rare but does occur during the winter months.
On average, the city receives about 3 inches of snow per year, primarily from December through February.
January is typically the month that records the most snowfall, although some years may see more significant snow events.
The snowfall is usually light, and significant accumulations are uncommon. However, ice and snowy conditions can cause disruptions.
When snow does fall, it often melts quickly, thanks to the typically mild winter temperatures that hover around freezing.
Residents of Portland should be prepared for occasional snow but can expect more rain throughout the winter season.
Average Sun in Portland, Oregon
Portland experiences varying levels of sunlight throughout the year, with significant changes between summer and winter. The amount of daylight and solar energy affects everything from temperatures to daily activities.
Average Daily Shortwave Solar Energy in Portland, Oregon
Portland’s daily shortwave solar energy varies by season.
During the summer months, the city receives more solar energy, averaging 6.5 kWh/m² in July. This is due to longer days and fewer clouds.
Clear skies dominate, with daylight lasting up to 15 hours near the longest day.
In winter, however, solar energy drops significantly to around 1.5 kWh/m² in December.
The shortest day of the year offers about 8.5 hours of daylight, often under overcast or partly cloudy skies.
Sunrise is later, and sunset comes earlier, reducing the amount of time the sun is visible.
Average Humidity in Portland, Oregon
Portland, Oregon, is known for its varying levels of humidity throughout the year.
December is the most humid month, with an average relative humidity of 83%. This coincides with cooler temperatures and increased rainfall.
In contrast, July is the least humid month, averaging 63% relative humidity. This lower humidity level occurs during the warmer summer months.
Here is a table summarizing monthly average humidity:
| Month | Average Humidity |
|---|---|
| January | 81% |
| February | 79% |
| March | 76% |
| April | 72% |
| May | 69% |
| June | 67% |
| July | 63% |
| August | 64% |
| September | 70% |
| October | 75% |
| November | 80% |
| December | 83% |
The annual average humidity in Portland is about 73%.
Dew points also vary, with higher dew points seen in more humid months like December. For reference, you can check monthly humidity data.
Average dew points range from 34°F in winter to about 57°F in summer.
High humidity combined with higher dew points in winter months often makes the air feel quite damp.
Average Wind in Portland, Oregon
Portland, Oregon experiences varying wind speeds throughout the year.
In general, winds in Portland are moderate. The average wind speed is around 11 mph, which can be experienced throughout much of the year.
The windiest month in Portland is typically March.
March sees an increase in wind speeds, with gusts that can occasionally reach higher velocities. This is a noticeable change compared to the calmer months.
Wind speeds in Portland can vary based on the hour of the day.
Mornings tend to be less windy, with calm breezes. Winds usually pick up in the afternoon, often peaking around late afternoon.
| Month | Average Wind Speed |
|---|---|
| January | 10 mph |
| February | 10 mph |
| March | 12 mph |
| April | 11 mph |
| May | 10 mph |
| June | 9 mph |
| July | 8 mph |
| August | 8 mph |
| September | 9 mph |
| October | 10 mph |
| November | 11 mph |
| December | 11 mph |
During the summer months, from June to August, winds are usually lighter. This period experiences gentle breezes with average speeds around 8 to 9 mph.
Winter winds, from December to February, can be stronger, often averaging around 11 mph. These months can see more frequent gusts due to changing weather patterns.
Average Air Quality in Portland, Oregon
Portland experiences varied air quality throughout the year.
June to September: Air quality is generally good because of lower levels of particulate matter and fewer temperature inversions. This period is also characterized by dry weather, which helps in maintaining better air quality.
November to February: Air quality can drop due to temperature inversions and increased heating activities. Cold weather during these months can trap pollutants closer to the ground.
Common Pollutants
- PM2.5: Particulate matter with diameters that are 2.5 micrometers and smaller.
- Ozone: Often higher during warmer months and can affect respiratory health.
- Nitrogen Dioxide (NO2): Increases in winter due to vehicle emissions and heating.
Air Quality Index (AQI) Classification
| AQI Value | Air Quality | Health Implications |
|---|---|---|
| 0-50 | Good | Air quality is considered satisfactory. |
| 51-100 | Moderate | Acceptable; some pollutants may be a concern for sensitive individuals. |
| 101-150 | Unhealthy for Sensitive Groups (USG) | Sensitive groups may experience health effects. |
| 151-200 | Unhealthy | Everyone may begin to experience health effects. |
| 201-300 | Very Unhealthy | Health alert: everyone may experience serious health effects. |
| 301-500 | Hazardous | Health warnings of emergency conditions. |
Monitoring of air quality is important for residents, especially during the cooler months and during wildfire season when PM2.5 levels can spike.
Regular updates from local weather services can help residents plan their activities.
Topography of Portland, Oregon
Portland is located at a latitude of around 45.52° N and a longitude of approximately 122.68° W. The city sits in a valley surrounded by mountains and hills.
The city’s elevation varies significantly.
Downtown Portland is roughly 50 feet above sea level, while higher points like the West Hills can reach elevations of about 1,000 feet.
Mount Tabor, an extinct volcanic cinder cone, lies to the east. It rises to about 636 feet and offers views of the city.
The Willamette River flows through the city, dividing it into east and west. The river’s path has shaped much of Portland’s development and infrastructure.
North of Portland, the Columbia River forms a border between Oregon and Washington. This river is a significant geographic feature for the area.
The city also has Forest Park, one of the largest urban forests in the United States, encompassing over 5,000 acres. This park is located in the Tualatin Mountains.
Table: Key Elevations
| Location | Elevation (Feet) |
|---|---|
| Downtown | ~50 |
| West Hills | ~1,000 |
| Mount Tabor | 636 |
Portland’s topography includes both flat areas suitable for agriculture and rolling hills that offer scenic views.
The balance of natural water bodies and higher elevations make for a diverse and unique urban landscape.
Extreme Weather Events that Occur in Portland, Oregon
Portland, Oregon, experiences a variety of extreme weather events that residents should be aware of.
Heat Waves: The city has faced record-breaking heat, such as the Pacific Northwest heat wave in June 2021 when temperatures soared to 116°F.
This event, fueled by climate change, brought dangerous heat levels that broke previous records.
Snow and Ice Storms: Winters in Portland can include unexpected snow and ice storms.
Snowfall is generally light, but certain years, like the winter storm in 2008, brought significant snow and disruption.
Ice storms, forming from freezing rain, can make roads hazardous.
Heavy Rainfall and Flooding: Portland sees substantial rainfall, especially during the winter months. Heavy rains can lead to flooding, affecting homes and transportation.
The city experienced severe flooding in 1996, which caused widespread damage.
Wind Storms: Strong winds can occasionally batter Portland, leading to power outages and downed trees.
These storms are usually more prevalent in the fall and winter months.
In December 2006, a wind storm brought gusts up to 57 mph, causing significant damage.
Wildfires: While wildfires are more common in the surrounding areas, smoke can drift into Portland, reducing air quality.
The city was impacted by smoke from the 2020 wildfires, prompting health warnings and urging people to stay indoors.
Best Time of the Year to Visit Portland, Oregon
Portland, Oregon has something to offer in every season. From blooming flowers in the spring to warm, sunny days in the summer, the city presents diverse experiences all year round.
What Is Portland, Oregon Like in Spring
Spring in Portland is mild and fresh. Temperatures range from the mid-40s to the mid-60s Fahrenheit.
This is when gardens and parks come alive with vibrant flowers, especially the famous roses at the International Rose Test Garden.
Rain is frequent, so it’s wise to pack an umbrella.
Spring is perfect for visiting the Portland Farmers Market, enjoying scenic walks, and participating in the annual Portland Rose Festival.
It’s a great time for anyone who enjoys mild weather and colorful landscapes.
What Is Portland, Oregon Like in Summer
Summers in Portland are warm and mostly dry. Average temperatures range from the upper 50s to the mid-80s Fahrenheit, making it ideal for outdoor activities.
June to August is the best time to visit as the weather is perfect for hiking, biking, and exploring the city’s numerous parks.
The long daylight hours also mean more time to enjoy activities along the Willamette River or visit the bustling neighborhoods.
Summer is peak tourism season, with events like the Oregon Brewers Festival drawing crowds.
What Is Portland, Oregon Like in Fall
Fall in Portland starts with warm days in September and cools down as the season progresses. Temperatures range from the upper 40s to the mid-70s Fahrenheit.
The vibrant fall foliage makes city parks and the surrounding nature areas stunning.
This is also the season for harvest festivals and wine tasting tours in the nearby Willamette Valley.
Rain begins to increase, especially in November, so visitors should be prepared for wetter weather towards the end of this season.
What Is Portland, Oregon Like in Winter
Winter in Portland is cool and wet.
Temperatures generally range from the mid-30s to the high 40s Fahrenheit.
Snow is rare in the city, though the nearby mountains offer skiing and snowboarding opportunities.
Rain is common, so waterproof clothing is a must.
Winter might not be the first choice for tourists, but it provides a quieter, more relaxed atmosphere.
Cozy cafes, indoor attractions like Powell’s City of Books, and holiday lights make it a charming time to visit.