Lahti, Finland climate

Dfb Warm-summer humid continental

Lahti has a seasonal cold-temperate climate (Warm-summer humid continental, Köppen Dfb). The hottest month is July with an average daily high near 23°C, while the coldest is February averaging around −10°C at night. Around 614 mm of precipitation falls each year, peaking in July (70 mm) and easing off in April (29 mm). At latitude 61°N, day length swings from 5.2 hours in midwinter to 18.8 hours at midsummer.

☀️ Summers

Mild

Highs near 23°C in July.

❄️ Winters

Very cold

Lows near −10°C in February.

About 170 freezing nights a year

🌧️ Rain

Moderate rainfall

About 614 mm of rain a year.

Wettest in July

⛅ Sky & trend

Often cloudy

Cloudy skies much of the year.

+0.8 °C vs 50 years ago

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Lahti climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	−3	−3	2	9	16	20	23	21	15	8	2	−1
Avg temp (°C)	−6	−6	−2	4	10	14	17	16	10	4	0	−4
Avg low (°C)	−9	−10	−7	−1	4	8	12	10	6	1	−2	−6
Precipitation (mm)	46	34	31	29	41	67	70	70	53	63	58	50

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	−3	−3	2	9	16	20
Avg temp (°C)	−6	−6	−2	4	10	14
Avg low (°C)	−9	−10	−7	−1	4	8
Precipitation (mm)	46	34	31	29	41	67

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	23	21	15	8	2	−1
Avg temp (°C)	17	16	10	4	0	−4
Avg low (°C)	12	10	6	1	−2	−6
Precipitation (mm)	70	70	53	63	58	50

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	19	15	13	11	11	12	13	13	13	15	18	19
Days with high ≥ 32°C (days)	—	—	—	—	—	0.0	0.3	0.1	—	—	—	—
Days with low ≤ 0°C (days)	29	26	28	19	7	0.3	—	—	3	13	19	25

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	19	15	13	11	11	12
Days with high ≥ 32°C (days)	—	—	—	—	—	0.0
Days with low ≤ 0°C (days)	29	26	28	19	7	0.3

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	13	13	13	15	18	19
Days with high ≥ 32°C (days)	0.3	0.1	—	—	—	—
Days with low ≤ 0°C (days)	—	—	3	13	19	25

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	75	70	65	66	62	65	63	63	67	75	77	77
Clear days (≤ 30% cloud)	2	3	4	4	5	3	4	5	3	2	2	2
Partly cloudy days (30–70%)	8	8	11	11	12	12	13	12	11	8	7	7
Cloudy days (≥ 70%)	21	17	15	15	14	14	14	14	15	21	21	22
Relative humidity (%)	99	99	95	83	77	77	79	81	86	93	97	98
Wind speed (mph)	1.2	1.3	1.6	1.6	1.4	1.2	1.2	1.2	1.2	1.1	1.0	1.1

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	75	70	65	66	62	65
Clear days (≤ 30% cloud)	2	3	4	4	5	3
Partly cloudy days (30–70%)	8	8	11	11	12	12
Cloudy days (≥ 70%)	21	17	15	15	14	14
Relative humidity (%)	99	99	95	83	77	77
Wind speed (mph)	1.2	1.3	1.6	1.6	1.4	1.2

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	63	63	67	75	77	77
Clear days (≤ 30% cloud)	4	5	3	2	2	2
Partly cloudy days (30–70%)	13	12	11	8	7	7
Cloudy days (≥ 70%)	14	14	15	21	21	22
Relative humidity (%)	79	81	86	93	97	98
Wind speed (mph)	1.2	1.2	1.2	1.1	1.0	1.1

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 28 years of daily observations at Lahti Laune, a weather station, about 3 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →