Climate averages 1991–2020
Lynn weather
in December.
A cold, wet month: the 10th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Lynn: daytime highs average 4.6°C and nights cool to about -1.5°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 116 mm of rain on roughly 11 days, which makes December a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 9 h 08 min on an average December day.
The nearest other city in this atlas is Boston (15 km away). In December its highs average 4.4°C, about as warm as Lynn, with 115 mm of rain.
Among the 498 cities listed in the United States, Lynn ranks joint 372nd of 498 for the warmest December highs and joint 448th of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Lynn is 6.0°C cooler than that mean.
From December to January, average highs fall by 3.0°C to 1.6°C, and monthly precipitation falls from 116 mm to 92 mm.
The annual picture
December in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Lynn climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.6°C-5.4°C | -5.4°C | 92 | 10.0 | 9.59 h |
| February | 2.7°C-4.8°C | -4.8°C | 84 | 9.1 | 10.511 h |
| March | 5.9°C-1.3°C | -1.3°C | 115 | 11.3 | 11.912 h |
| April | 11.4°C4.2°C | 4.2°C | 103 | 10.7 | 13.313 h |
| May | 16.7°C9.6°C | 9.6°C | 84 | 10.7 | 14.615 h |
| June | 21.8°C15.0°C | 15.0°C | 88 | 10.3 | 15.215 h |
| July | 25.2°C18.6°C | 18.6°C | 74 | 9.9 | 15.015 h |
| August | 24.6°C18.3°C | 18.3°C | 85 | 9.0 | 13.914 h |
| September | 21.0°C14.8°C | 14.8°C | 87 | 8.2 | 12.513 h |
| October | 15.2°C9.1°C | 9.1°C | 109 | 10.1 | 11.111 h |
| November | 9.6°C3.6°C | 3.6°C | 96 | 9.6 | 9.810 h |
| December, selected | 4.6°C-1.5°C | -1.5°C | 116 | 10.6 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Boston in DecemberUnited States · 15 kmHigh 4.4°C · Low -3.1°C · 115 mm rain
- Dorchester in DecemberUnited States · 21 kmHigh 4.6°C · Low -2.4°C · 115 mm rain
- Quincy in DecemberUnited States · 24 kmHigh 4.9°C · Low -1.6°C · 115 mm rain
- Newton in DecemberUnited States · 26 kmHigh 4.6°C · Low -2.6°C · 107 mm rain
- Lawrence (Massachusetts), United States in DecemberUnited States · 32 kmHigh 3.9°C · Low -3.4°C · 104 mm rain
- Lowell in DecemberUnited States · 35 kmHigh 4.0°C · Low -3.4°C · 104 mm rain
- Brockton in DecemberUnited States · 43 kmHigh 5.1°C · Low -1.6°C · 110 mm rain
- Nashua in DecemberUnited States · 54 kmHigh 3.3°C · Low -4.2°C · 105 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Lynn) is explained once on the Lynn year overview and on the Sources, method and limits page.