Lahti weather in December

In December, Lahti sees average daytime highs of -1°C and overnight lows near -5°C, with 48 mm of precipitation across 11.6 wet days and about 5.3 hours of daylight. It is the 10th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 0°C in the first days to -3°C by the end. The sky is clear or mostly clear about 8% of the time in December, and the air most often feels dry.

Daylight stretches from about 5 h 48 min at the start of December to 5 h 18 min by month's end. Set against the rest of the year, December is Lahti's 11th-clearest and 1st-windiest month. For the whole year in context, see Lahti's year-round climate.

Daytime high
-1°
10th warmest
Overnight low
-5°
4th coldest
Precipitation
48 mm
11.6 wet days
Daylight
5 h 12 min
9:37 AM – 2:50 PM
Cloud cover
86%
11th clearest
Wind
13 km/h
1st windiest
Solar energy
0.12 kWh/m²
Travel score
0.0
out of 10
Air quality
Excellent
PM2.5 4.3 µg/m³ · 2019

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 0°C in the first days to -3°C by the end.

A typical December day in Lahti reaches about -1°C in the afternoon and slips back to -5°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between -9°C and 4°C. Set against its neighbours, December runs about 3°C cooler than November and about 2°C warmer than January.

-20°-10°10°151015202531
Avg high (°C)Avg low (°C)
10-3
20-3
30-3
40-3
50-3
60-4
70-4
80-4
90-4
100-4
11-1-4
12-1-4
13-1-5
14-1-5
15-1-5
16-1-5
17-1-5
18-2-6
19-2-6
20-2-6
21-2-6
22-2-6
23-2-6
24-2-7
25-2-7
26-3-7
27-3-7
28-3-7
29-3-7
30-3-7
31-3-7

How December really feels in Lahti

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
31
17 feel bitter (≤ -10°C)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Lahti weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-3° / -8°4110.310.76.10.0
Feb-3° / -9°348.28.78.50.0
Mar / -6°338.48.211.30.0
Apr / -1°358.83.414.21.3
May15° / 48100.2174.3
Jun19° / 10°7512.3018.75.5
Jul21° / 13°7612.40186.1
Aug20° / 12°6811.7015.55.8
Sep14° / 519.8012.64.0
Oct / 5611.11.69.71.0
Nov / -1°5010.85.56.90.0
Dec-1° / -5°4811.69.95.30.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 8% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 5% of December, with mostly cloudy or overcast conditions the remaining 87%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11288
21288
31189
41189
51288
61288
71189
81189
91288
101288
111189
121189
131189
141189
151189
161288
171288
181387
191387
201387
211486
221486
231486
241585
251585
261684
271684
281684
291783
301783
311783

Chance of precipitation in December

Any precipitationSnow

Lahti gets around 48 mm of rain and snow over 11.6 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 37% and peaks near 38% on the wettest days, and about 10 days bring snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
13826
23827
33827
43828
53828
63829
73829
83830
93830
103831
113731
123732
133732
143633
153633
163633
173633
183633
193633
203633
213633
223634
233634
243634
253634
263634
273634
283634
293634
303634
313634

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 13 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 13 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 5 h 48 min at the start of December to 5 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 30 minutes over December. Sunrise moves from 9:13 AM to 9:42 AM, and sunset from 3:01 PM to 2:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
15.89:133:01
25.79:153:00
35.79:172:58
45.69:192:57
55.69:212:56
65.59:232:55
75.59:252:54
85.49:272:53
95.49:282:53
105.49:302:52
115.39:312:51
125.39:332:51
135.39:342:50
145.29:352:50
155.29:362:50
165.29:372:50
175.29:382:50
185.29:392:50
195.29:402:50
205.29:412:50
215.19:412:50
225.19:422:51
235.19:422:51
245.29:432:52
255.29:432:53
265.29:432:53
275.29:432:54
285.29:432:55
295.29:432:56
305.29:432:57
315.39:422:59

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 0.12 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 0.12 kWh/m² to a high of 5.28 kWh/m² in June across the year — December's 0.12 kWh/m² sits near the bottom.

00.511.52151015202531
Solar energy (kWh/m²)Level
10.2Dim
20.1Dim
30.1Dim
40.1Dim
50.1Dim
60.1Dim
70.1Dim
80.1Dim
90.1Dim
100.1Dim
110.1Dim
120.1Dim
130.1Dim
140.1Dim
150.1Dim
160.1Dim
170.1Dim
180.1Dim
190.1Dim
200.1Dim
210.1Dim
220.1Dim
230.1Dim
240.1Dim
250.1Dim
260.1Dim
270.1Dim
280.1Dim
290.1Dim
300.1Dim
310.1Dim
Planning a trip in December

Is December a good time to visit Lahti?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.0
Sightseeing
8th-best month of the year
0.0
Beach & pool
6th-best month of the year

December is a weaker month for outdoor sightseeing in Lahti.

What to pack for Lahti in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Lahti sees daytime highs around -1°C and nights near -5°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 12 days see rain.

a warm layera heavy coatrain gear

UV index in Lahti in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 0. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Lahti peaks around June 19 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 4 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 19UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep2Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Lahti?

Lahti sits at 61.0°N, 25.7°E, 105 m above sea level, in Finland. The nearest listed city is Hollola, 9.0 km away.

Topography around Lahti

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Lahti.

Within 3 km, the terrain around Lahti has only modest variations in elevation — a maximum elevation change of 91 m around an average of 104 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 164 m; within 80 km, only modest variations in elevation — a maximum elevation change of 226 m.

The land around Lahti is covered by trees (51%) and artificial surfaces (35%) within 3 km, trees (65%) within 16 km, and trees (71%) within 80 km.

3 km
91 m
16 km
164 m
80 km
226 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Hollola 9.0 km · Orimattila 20 km · Heinola 32 km · Mäntsälä 43 km · Riihimäki 55 km · Kouvola 58 km · Hyvinge 58 km · Janakkala 58 km

Finland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 85% of US
price level, 2025
GDP per capita
$56,149
2025
Happiness
7.8 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1
per 100k, 2023
Road deaths
3.9
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 603
Religion
Lutheran 67%none 31%other 2%Greek Orthodox 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Lahti (60.9827°, 25.6615°, elevation 105 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).