Portland · December
Run in the midday.
Cold: average high 46°F, low 36°F. Layering becomes the workout. Humidity averages 86% — the limiting factor on most runs. Expect 22 rain days — plan around the radar. Cold mornings warm into runnable midday hours — the windows around noon catch the warmest temperatures.
Avg high / low
46° / 36°F
Humidity
86%
Rain days
22/mo
Wind
12 mph
What December feels like in Portland
Sunrise
08:43
Mid-month average
Sunset
17:29
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Mild but UV and traffic peak. Workable if you don't mind shifting your pace.
Evening
Warm and runnable. Crowded routes but the air's typically calm.
What to wear running in Portland in December
The kit for December in Portland: a long-sleeve or light jacket for the first mile, a water-resistant cap or jacket on standby.
December vs the surrounding months
vs November
-6° avg high
+3 rain days
Portland in November →
December
46°F avg high
22 rain days
Best: midday
vs January
-2° avg high
+2 rain days
Portland in January →
Frequently Asked Questions
What is the best time of day to run in Portland in December?+
Midday. Cold mornings warm into runnable midday hours — the windows around noon catch the warmest temperatures.
What's the average temperature in Portland in December?+
Average high 46°F, average low 36°F.
How does December compare to surrounding months in Portland?+
Compared to November (avg high 52°F), December is cooler. Compared to January (avg high 47°F), December is cooler.
Does it rain often in Portland in December?+
Expect about 22 measurable rain days in December, on average.