Portland Weather in December
United States · Oceanic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
December in Portland sees average temperatures ranging from a low of 2.6°C (36.7°F) to a high of 7.9°C (46.2°F), with a mean of 5.1°C (41.2°F). Compared to the annual average of 11.9°C (53.4°F), this month is 6.8°C cooler than the yearly norm. Precipitation averages 247.2mm, making it approximately 128.0mm wetter than the monthly average of 120.0mm. This is the wettest month of the year, with 247.2mm of precipitation and around 22.2 rainy days. The city receives an average of 3.5 hours of sunshine per day during December, with relative humidity averaging 85.9%. Wind speeds reach an average maximum of 20.7 km/h. Snowfall averages 7.2cm during December, which can affect travel plans and outdoor activities. For travelers, this month offers a temperature experience in Portland, with wetter-than-average conditions compared to the rest of the year.
Portland's climate is similar to Seattle but with slightly warmer summers and cooler winters. I visited during the famous rose festival in June and found the weather ideal. The data shows that the best time to visit is June to September, when the rainfall is minimal and the city's famous outdoor culture thrives. The winter months are grey and wet but the city's coffee shop culture makes it cozy.
December vs Adjacent Months
| Metric | November | December | January |
|---|---|---|---|
| Mean Temp | 7.1°C (44.8°F) | 5.1°C (41.2°F) | 5.1°C (41.2°F) |
| Rainfall | 220.8mm | 247.2mm | 238.0mm |
| Sunshine | 4.8 hrs | 3.5 hrs | 3.6 hrs |
| Humidity | 84.4% | 85.9% | 85.8% |
| Wind | 19.1 km/h | 20.7 km/h | 21.1 km/h |
| Rainy Days | 20.0 | 22.2 | 23.0 |
| Snowfall | 1.5 cm | 7.2 cm | 5.5 cm |
Seasonal Context
December falls in Winter in the Northern Hemisphere. Winter is the coolest season with the shortest daylight hours. For travelers visiting Portland in December, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Portland in December?
The average temperature in Portland during December ranges from 2.6°C (36.7°F) to 7.9°C (46.2°F), with a mean of 5.1°C (41.2°F).
How much does it rain in Portland in December?
Portland receives an average of 247.2mm of precipitation in December, spread across approximately 22.2 rainy days. This is the wettest month of the year.
What should I pack for Portland in December?
Based on December weather data, pack warm layers, a medium jacket, and waterproof outerwear. Rain gear is essential — this month averages 247.2mm of precipitation.
Is December a good time to visit Portland?
December is a cooler month, suitable for travelers who prefer mild weather and fewer crowds. Pack warm layers and enjoy indoor attractions.
Other Months for Portland
Cities with Similar December Climate (Oceanic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 45.52°, -122.68°. Timezone: America/Los_Angeles. Last updated: 2026-07-30.