Boston · December
Run in the midday.
Cold: average high 43°F, low 29°F. Layering becomes the workout. Cold mornings warm into runnable midday hours — the windows around noon catch the warmest temperatures.
Avg high / low
43° / 29°F
Humidity
73%
Rain days
14/mo
Wind
13 mph
What December feels like in Boston
Sunrise
08:06
Mid-month average
Sunset
17:14
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
Often the warmest few hours of a cold day. If you can only run once, midday gives you the most temperate window.
Evening
Cold drops back in fast after sunset. Tight window — done before headlamp territory.
What to wear running in Boston in December
The kit for December in Boston: cold-weather layers, gloves, and ear coverage on most mornings, a water-resistant cap or jacket on standby.
December vs the surrounding months
vs November
-8° avg high
+3 rain days
Boston in November →
December
43°F avg high
14 rain days
Best: midday
vs January
+6° avg high
+1 rain days
Boston in January →
Frequently Asked Questions
What is the best time of day to run in Boston in December?+
Midday. Cold mornings warm into runnable midday hours — the windows around noon catch the warmest temperatures.
What's the average temperature in Boston in December?+
Average high 43°F, average low 29°F.
How does December compare to surrounding months in Boston?+
Compared to November (avg high 51°F), December is cooler. Compared to January (avg high 37°F), December is warmer.
Does it rain often in Boston in December?+
Expect about 14 measurable rain days in December, on average.