Last updated: February 24, 2025
In May, Portland experiences a tantalizing blend of spring warmth and moisture, with maximum temperatures soaring to 32°C (90°F), while the average temperature settles at a comfortable 14°C (58°F). The month brings an average minimum temperature of 2°C (36°F), offering cool evenings perfect for cozy outings. Rainfall is prominent, with 58 mm (2.3 in) of precipitation spread over 10 days, contributing to the area's lush greenery. High humidity levels at 83% create a vibrant, refreshing atmosphere that invigorates the senses. Enjoy the unique charm of Portland in May, where every day offers the promise of both sunshine and spring showers.
In May, Portland experiences a delightful shift toward warmer weather, marking a vibrant spring transition. With minimum temperatures starting at 2°C (36°F) and soaring to a comfortable 32°C (90°F), this month showcases a substantial leap from the cooler months preceding it. The average temperature stabilizes at a pleasant 14°C (58°F), inviting residents to embrace outdoor activities and the blooming scenery. This trend of rising temperatures sets the stage for the summer ahead, as the city shakes off the lingering chill of winter and welcomes longer, sunnier days filled with the essence of nature in full bloom. Whether basking in the sun or enjoying the refreshing evenings, May in Portland is a time of rejuvenation and unfolding beauty.
In Portland, May marks a delightful transitional phase as precipitation takes a noticeable dip, with an average of just 58 mm (2.3 in), making it one of the driest months in the year. This lighter rainfall is accompanied by a decrease in rainy days, dropping to only 10 days, fostering a vibrant atmosphere perfect for outdoor activities. The trend from April to May illustrates a significant reduction in water accumulation—April boasts 117 mm (4.6 in) over 15 days. As spring nears its end, the city experiences more sunshine and blooming landscapes, inviting residents and visitors alike to celebrate the onset of summer with clearer skies and fewer interruptions from rain.
In May, Portland enjoys a pleasant and relatively stable humidity level of 83%, mirroring the trend seen in April. As the city transitions from the chill of spring into the warmth of summer, humidity remains consistent, suggesting a comfortable atmosphere for outdoor activities. Notably, the humidity gradually decreases as the summer months approach, dipping to 82% in July and reaching a seasonal low of 74% in August. This gradual decline contrasts sharply with the winter months, where humidity peaks at a high 87% in both November and December. Overall, May serves as a bridge, offering a balance of moisture that precedes the drier summer days, enhancing Portland’s scenic beauty and outdoor appeal.
As May unfolds in Portland, the UV Index surges to an impressive 9, marking it as a month of very high sun exposure risk. This significant jump from April's Index of 6 emphasizes the need for proactive sun protection, with a rapid decrease in burn time to just 15 minutes. Historically, this trend marks the kickoff of Portland's sunlit summer, where outdoor enthusiasts flock to parks and rivers. With UV levels peaking in the coming months, understanding and adapting to these shifts is crucial for skin safety. For those keen on tracking these fluctuations further, the comprehensive details can be found at Portland UV Index.
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As May unfolds in Portland, the city basks in 282 hours of brilliant sunshine, marking a delightful leap from the previous months. This sunny month continues the upward trend initiated in April, where residents welcomed 229 hours of light, setting the stage for the warmth of early summer. May's sunshine hours not only reflect the gradual shift towards more luminous days but also foreshadow the peak brightness experienced in June with a striking 318 hours. The transition from the dreary depths of winter, where January only saw a mere 88 hours, highlights Portland's transformation into a sun-soaked paradise as it heads into the summer months. This gradual increase not only lifts spirits but enhances the beauty of the city, making it a perfect time for outdoor activities and experiencing the vibrant life that flourishes under the sun.
As spring gives way to summer in Portland, May offers a mixed bag of sunshine with a 37% chance of clear skies. While this is a dip from April's more promising 54%, it still shows a healthy shift from the more overcast months of winter, where the chances of sun hover around 16% to 17%. Interestingly, this trend reflects the city’s gradual transition into sunnier months, as June marks a substantial leap to 63%, and July continues to shine with a remarkable 74%. Overall, while May may not boast the highest likelihood of sunny weather, it certainly provides a glimpse of the bright days just around the corner—perfect for outdoor activities and enjoying the bloom of early summer.
As the year progresses in Portland, the daylight duration reveals a captivating transformation, particularly noticeable in May when the city enjoys approximately 14 hours of sunlight. This marks a significant increase from the 11 hours of daylight in March and a remarkable leap from the 10 hours in February. Following a steady rise through April, May serves as a bridge to the longest days of summer in June and July, both boasting 15 hours of light. This gradual lengthening of days invites residents outdoors, encouraging vibrant spring activities and connection with nature before the summer season begins to ebb. As autumn approaches, the trend reverses, transitioning back to shorter days, emphasizing the fleeting beauty of Portland’s seasonal daylight.
May in Portland brings a gentle consistency in wind speed, averaging 2.4 m/s (5 mph). This mirrors the tranquility felt through the earlier spring months of April and March, which also hover around similar figures. As the seasons transition into summer, the wind remains steady, fluctuating slightly but generally maintaining a mild pace akin to the previous months. This light and refreshing breeze complements the blooming landscapes of May, making it an ideal time for outdoor activities. Overall, the wind patterns in May continue to reflect Portland's characteristic calmness, setting the stage for the vibrant summer ahead.
The weather in Portland changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of May's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Portland and find detailed weather information for every month.
In comparing the weather of May and January, one can see a stark contrast in temperature and precipitation patterns. May offers a mild climate with average temperatures around 14°C (58°F) and a maximum that can reach up to 32°C (90°F), alongside a relatively low precipitation of 58 mm (2.3 in) over about 10 days. In contrast, January is much colder, with average temperatures of just 5°C (42°F) and lows dipping to -14°C (7°F). This winter month experiences significantly higher precipitation, totaling 163 mm (6.4 in) spread over 17 days, creating a much wetter and chillier environment. For a detailed look at January weather, you can visit Portland weather in January.
When comparing the weather in May and February, we see a striking difference in temperatures and precipitation patterns. May boasts milder conditions with minimum temperatures around 2°C (36°F) and an average of 14°C (58°F), peaking at a warm 32°C (90°F). In contrast, February experiences colder temperatures, with lows plummeting to -7°C (19°F) and a modest average of 5°C (41°F), reaching a maximum of only 17°C (63°F). Additionally, February is significantly wetter, receiving 172 mm (6.8 in) of precipitation over 19 days, compared to May's 58 mm (2.3 in) over just 10 days. Both months have high humidity levels, but February's conditions tend to feel much chillier despite a similar humidity of 84%. For a closer look at February's weather specifics, check out Portland weather in February.
In comparing the weather between March and May, it is clear that May offers a milder and more pleasant climate. May's temperatures range from a minimum of 2°C (36°F) to a maximum of 32°C (90°F), with an average of 14°C (58°F). In contrast, March is much cooler, with temperatures ranging from -4°C (26°F) to 24°C (75°F) and an average of 8°C (46°F). Additionally, March experiences significantly more precipitation, totaling 135 mm (5.3 in) over 17 days, compared to May's 58 mm (2.3 in) over just 10 days. Humidity levels are similar, hovering around 83% in May and slightly higher at 85% in March. For more detailed information, you can visit Portland weather in March.
In comparing the weather between April and May, May generally offers warmer temperatures, with an average of 14°C (58°F) and a maximum of 32°C (90°F), compared to April's average of 11°C (51°F) and a maximum of 29°C (84°F). While both months share the same humidity level of 83%, April tends to be wetter, recording 117 mm (4.6 in) of precipitation over 15 days, in contrast to May’s 58 mm (2.3 in) over 10 days. For more detailed insights on April weather, check out Portland weather in April.
In comparing the weather between May and June, we see a notable increase in average temperatures, with May averaging 14°C (58°F) compared to June's average of 18°C (64°F). The maximum temperature in June can reach up to 47°C (118°F), significantly higher than May's max of 32°C (90°F). Despite these warmer conditions, June experiences slightly less precipitation, with 46 mm (1.8 in) over 8 days, compared to May's 58 mm (2.3 in) over 10 days. Both months maintain a consistent humidity level of 83%, creating a somewhat muggy atmosphere in both. For a more detailed look at June's specific weather patterns, you can visit Portland weather in June.
In comparing the weather between May and July, May experiences a broader range of temperatures, with minimums dropping to 2°C (36°F) and maximums climbing to 32°C (90°F), while July maintains milder lows at 9°C (49°F) and warmer highs reaching up to 37°C (99°F). Precipitation levels also differ significantly; May sees about 58 mm (2.3 in) spread over 10 days, whereas July typically has much less rain, with only 6 mm (0.2 in) over just 1 day. Humidity remains relatively constant, with May at 83% and July slightly lower at 82%. For more detailed information on July's weather, visit Portland weather in July.
May weather is characterized by a wider temperature range, with minimums dropping to 2°C (36°F) and maximums soaring to 32°C (90°F), leading to an average of 14°C (58°F). It tends to be quite humid at 83%, and precipitation is relatively frequent, occurring on around 10 days with a total of 58 mm (2.3 in). In contrast, August offers warmer and more stable temperatures, with a minimum of 9°C (48°F) and a maximum reaching up to 40°C (104°F), resulting in a higher average temperature of 21°C (70°F). The month is notably drier, with only 8 mm (0.3 in) of precipitation over just 2 days and lower humidity at 74%. For more information about weather conditions in Portland during August, check out Portland weather in August.
In comparing May and September weather, May tends to be slightly cooler, with average temperatures ranging from a minimum of 2°C (36°F) to a maximum of 32°C (90°F), while September's averages lie between 6°C (42°F) and 35°C (95°F). May experiences a higher humidity level at 83%, compared to September's more comfortable 71%. Precipitation is relatively similar, with May receiving 58 mm (2.3 in) over 10 days and September having 62 mm (2.4 in) over just 8 days. For a more detailed look at the weather in September, visit Portland weather in September.
May and October present contrasting weather patterns, reflective of their positions in the spring and autumn seasons. In May, temperatures range from a minimum of 2°C (36°F) to a maximum of 32°C (90°F), with an average of 14°C (58°F), and the month experiences 58 mm (2.3 in) of precipitation over about 10 days, accompanied by relatively high humidity at 83%. In contrast, October sees cooler temperatures, with a minimum of -2°C (29°F), an average of 12°C (53°F), and a maximum of 26°C (79°F). This month also receives more rainfall, totaling 105 mm (4.1 in) across approximately 12 days, while humidity is slightly lower at 81%. For more specific insights into October weather conditions, you can explore Portland weather in October.
May and November present contrasting weather patterns, reflecting the transition from spring to winter. In May, temperatures range from a mild 2°C (36°F) to a warm 32°C (90°F), with an average of 14°C (58°F) and relatively low precipitation of 58 mm (2.3 in) over about 10 days. The humidity stands at 83%, giving the month a comfortable feel overall.
In contrast, November features cooler temperatures, with a minimum of -5°C (24°F), an average of 8°C (47°F), and a maximum of 19°C (67°F). This month experiences significantly more rainfall, totaling 155 mm (6.1 in) spread across approximately 18 days, contributing to a higher humidity level of 87%. For more insights on the specifics of November weather, visit Portland weather in November.
May and December present stark contrasts in weather conditions. In May, temperatures range from a chilly minimum of 2°C (36°F) to a warm maximum of 32°C (90°F), with an average of 14°C (58°F). The month experiences lighter precipitation, averaging 58 mm (2.3 in) over about 10 days and boasts a humidity level of 83%. In contrast, December is notably colder, with temperatures dipping as low as -5°C (24°F) and averaging 5°C (41°F), reaching a maximum of 16°C (60°F). This month is also significantly wetter, receiving 183 mm (7.2 in) of precipitation over 19 days and exhibiting a higher humidity of 87%. For a deeper look into December’s conditions, you can check out this link: Portland weather in December.
As May graces Portland, the city transitions into a vibrant spring, showcasing a delightful mix of warmer temperatures and blooming flora. Unlike the cooler, drab skies of winter and early spring, May brings a lively atmosphere with its average temperature settling comfortably, although it can spike to summer-like highs. However, the month is also characterized by increased humidity and a fair share of rain, with over ten days experiencing precipitation. This balance of warmth and moisture sets the stage for lush landscapes and invigorating outdoor activities, making it a uniquely enchanting time. For more on the city's climate patterns, visit Portland Climate.