Climate averages 1991–2020
Lahti weather
in December.
A freezing month with moderate precipitation: the 10th warmest and the joint 5th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a freezing month in Lahti: daytime highs average -1.5°C and nights cool to about -5.2°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 48 mm of precipitation on roughly 12 days, which makes December a month with moderate precipitation (the joint 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 5 h 44 min on an average December day.
The nearest other city in this atlas is Kouvola (58 km away). In December its highs average -1.6°C, about as warm as Lahti, with 54 mm of precipitation.
Among the 13 cities listed in Finland, Lahti ranks joint 6th of 13 for the warmest December highs and 4th of 13 for the driest December (precipitation, lowest first). The mean December high of those 13 cities is -1.3°C; Lahti is 0.2°C cooler than that mean.
From December to January, average highs fall by 2.1°C to -3.6°C, and monthly precipitation falls from 48 mm to 41 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
Lahti climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -3.6°C-8.0°C | -8.0°C | 41 | 10.3 | 6.57 h |
| February | -3.7°C-8.7°C | -8.7°C | 34 | 8.2 | 9.09 h |
| March | 0.7°C-5.7°C | -5.7°C | 33 | 8.4 | 11.712 h |
| April | 7.4°C-0.6°C | -0.6°C | 35 | 8.8 | 14.615 h |
| May | 14.5°C5.6°C | 5.6°C | 48 | 10.0 | 17.417 h |
| June | 18.6°C10.8°C | 10.8°C | 75 | 12.3 | 19.119 h |
| July | 21.2°C13.9°C | 13.9°C | 76 | 12.3 | 18.318 h |
| August | 19.6°C12.9°C | 12.9°C | 68 | 11.6 | 15.816 h |
| September | 14.1°C8.5°C | 8.5°C | 51 | 9.8 | 13.013 h |
| October | 7.0°C3.0°C | 3.0°C | 56 | 11.1 | 10.110 h |
| November | 1.8°C-1.3°C | -1.3°C | 50 | 10.8 | 7.47 h |
| December, selected | -1.5°C-5.2°C | -5.2°C | 48 | 11.6 | 5.76 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
- Kouvola in DecemberFinland · 58 kmHigh -1.6°C · Low -5.5°C · 54 mm precipitation
- Vantaa in DecemberFinland · 84 kmHigh -0.2°C · Low -4.1°C · 55 mm precipitation
- Helsinki in DecemberFinland · 99 kmHigh 0.1°C · Low -3.2°C · 55 mm precipitation
- Espoo in DecemberFinland · 103 kmHigh 0.3°C · Low -3.0°C · 57 mm precipitation
- Tampere in DecemberFinland · 116 kmHigh -1.5°C · Low -4.7°C · 46 mm precipitation
- Lappeenranta in DecemberFinland · 136 kmHigh -2.0°C · Low -5.5°C · 52 mm precipitation
- Jyväskylä in DecemberFinland · 140 kmHigh -2.2°C · Low -6.0°C · 46 mm precipitation
- Vyborg in DecemberRussia · 170 kmHigh -1.4°C · Low -5.0°C · 59 mm precipitation
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 Lahti) is explained once on the Lahti year overview and on the Sources, method and limits page.