Early winter · Weather & things to do
Portsmouth in December
The year's rain peaks now, with about 5.7 in (144 mm) falling in Portsmouth, alongside highs near 40°F (4°C) and lows of 31°F (-1°C).
With a comfort score of 36/100 (12th of 12), it's one of the toughest months, held back mainly by cool days.
- Avg high
- 40°F (4°C)
- Avg low
- 31°F (-1°C)
- Rain
- 5.7 in (144 mm)
- Humidity
- 84%
- Cloud cover
- 66%
- Daylight
- ~8 h 50 min
- Comfort score
- 36/100 · Tough
What December feels like
It's cold: daytime highs average just 40°F (4°C), so build the days around warm stops.
Nights drop below freezing, with an average low of 31°F (-1°C), so expect frost and ice.
Expect regular rain: about 5.7 in (144 mm) falls in the month.
Daylight is short, roughly 8 h 50 min mid-month, so start sightseeing early.
Plan around December
December is one of the lower-scoring months here; the best are September.
- Freezing nights return: average lows drop to 31°F.
- Inside the wettest three-month stretch, October – December.
- Shortest days of the year, about 8 h 50 min of daylight.
- Comfort slips from 54/100 in November to 36/100.
- Our Boston to Portland route recommends May – Oct, so December falls outside its suggested window.
What to pack for December
- Hat, gloves and thermal base layerslows around 31°F
- Shoes with gripfrost and ice are possible
- Rain jacket and waterproof shoes5.7 in of rain on average
- Comfortable walking shoesmost picks involve some walking
What to do in Portsmouth in December
Wet days call for a roof: these picks favor sit-down and indoor stops, plus a few for drier spells.
Strawbery Banke Museum
Ten acres of restored houses spanning 300 years of a waterfront neighborhood.
Why now An indoor-leaning stop for a month with 5.7 in of rain.
USS Albacore Museum
Walk through a 1953 experimental submarine on dry land.
Why now A good rainy-day backup in December.
Ceres Bakery
Long-running downtown bakery for coffee, scones and soup.
Why now A sit-down stop to wait out showers in a month with 5.7 in of rain.
Odiorne Point State Park
Rocky shoreline trails and tide pools, plus the Seacoast Science Center.
Moxy
Chef Matt Louis's American tapas using New England ingredients.
Why now Easy to slot in when December's rain moves in.
Nearby in December
- New Hampshire in December~42 mi · highs 36°F, 4.2 in rain or snow · 2°C (4°F) cooler by day, drier
- Portland, Maine in December~48 mi · highs 40°F, 5.6 in rain · similar daytime temperatures, about as wet
- Boston in December~51 mi · highs 39°F, 4.6 in rain or snow · similar daytime temperatures, drier
- White Mountains in December~87 mi · highs 11°F, 4.1 in rain or snow · 16°C (29°F) cooler by day, drier
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Portsmouth in December: quick answers
Is December a good time to visit Portsmouth?
It's one of the tougher months here, scoring 36/100, held back mainly by cool days. The best months are September. Expect highs of 40°F (4°C) and 5.7 in (144 mm) of rain. Our Boston to Portland route recommends May – Oct, so December is outside its suggested window.
How cold is Portsmouth in December?
Average highs are 40°F (4°C) and average lows 31°F (-1°C), making it the 3rd-coldest month by daytime highs, with nights below freezing on average.
Does it rain a lot in Portsmouth in December?
Yes: about 5.7 in (144 mm) of rain falls across December on average, the wettest month of the year. The annual total is about 52.6 in (1337 mm).
What should I pack for Portsmouth in December?
Bring hat, gloves and thermal base layers (lows around 31°F), shoes with grip (frost and ice are possible), rain jacket and waterproof shoes (5.7 in of rain on average) and comfortable walking shoes (most picks involve some walking).
Planning Portsmouth in December?
Plan it together in TripsCircle: one itinerary, one shared packing list and costs split as you go.