Mosfellsbær Weather in December
Mosfellsbær in December sees low temperatures, with highs around 3°C (37°F) and overnight lows of -3°C (27°F). Snow/rainfall is fairly high at around 143 mm (5.6 in) on average, so pack waterproofs just in case.
Rainfall in Mosfellsbær in December
Climate statistics over the past 30 years suggest around 19 days of snow/rain, with 143 mm (5.6 in) average for the month. Rain falls regularly this month and can be quite heavy when it does. Showers can be substantial, so waterproof gear is a good idea.
Temperature in Mosfellsbær in December
Temperatures in Mosfellsbær in December top out at 3°C (37°F) and drop to -3°C (27°F) overnight. This month falls in the winter season. Time outdoors is usually more comfortable with proper winter clothing and protection from wind. Nights are well below freezing at -3°C (27°F). An extra blanket is a good idea if you feel the cold, especially in older or less well-heated accommodation. This month is marked by cold temperatures, so wearing layers is key to staying warm. Don't be caught off-guard by the cold.
Sunshine in Mosfellsbær in December
The area experiences limited sunny days, amounting to roughly 20 hours of sunshine. This makes it perfect for those who lean towards cooler, cloudier settings rather than intense sunlit days.
Wind Speed in Mosfellsbær in December
Wind speeds average 6 m/s (12 knots) during December. At this speed, expect strong winds that make large branches move and create some resistance when walking. Since this is an average, some days have fresh winds while others have strong breezes that can make umbrellas tricky to control.
Average water temperature in December
The water temperature is only 7°C (45°F) this month — cold enough that most people will want to stay out. Hardy swimmers may manage a quick dip, but it won't be comfortable.December in Mosfellsbær can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Mosfellsbær's climate page.
Mosfellsbær Temperature in December
Min Temperature
-3°C (27°F)
Max Temperature
3°C (37°F)
Water Temperature
7°C (45°F) *
Chance of Rain
64%
Precipitation
143 mm (5.6 in)
Rainy days
19 days
Humidity
79% *
Windspeed
6 m/s (12 knots) *
Sunshine
20 hours *
Percentage Sunshine
15% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Mosfellsbær typically stay consistent throughout December, with daily highs averaging around 3°C (37°F). Nights are very cold, with lows typically ranging from -3°C (27°F) to 0°C (32°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for Mosfellsbær in December
Browse day-by-day weather records for Mosfellsbær spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Mosfellsbær historical weather extremes in December
The extremes listed below come from historical weather data collected in Mosfellsbær from 1976 through 2025.
- The warmest day in December was on December 14, 1997, with a maximum of 11°C (52°F).
- The coldest December day was on December 30, 2022, with a maximum of -9°C (16°F).
- The coldest night in December in Mosfellsbær was on December 30, 2022, with a minimum of -14°C (7°F).
- The wettest day in December Mosfellsbær was on December 30, 2007 with 56 mm (2.2 in) of precipitation.
Best Places in Iceland in December
Find out more about the weather in Iceland and which places have the best travel conditions in this month. See all of Iceland in December →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Mosfellsbær in December
Cold weather calls for smart layering in December. A thermal base layer makes a huge difference in staying warm. Add a wool sweater or fleece, then a wind-resistant outer jacket. Prepare for significant rainfall with proper waterproof clothing and shoes. With water temperatures around 7°C (45°F), the water is quite cold for swimming. You can skip the swimwear unless you're particularly tough. You can probably leave your sunglasses at home, because sunny days are pretty rare this month.What To Do in Mosfellsbær in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Mosfellsbær's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Mosfellsbær climate overview or explore weather in Iceland.
