Lammi climate — normals and trends
Lammi (Finland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 4.4 °C and it receives 634 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (16.9 °C on average) and the coldest is January (-7.2 °C). Rainfall peaks in July.
Lammi averages 159 frost days, 1 hot days (≥ 30 °C) and 131 rainy days per year.
Lammi has warmed by +2.4 °C between 1940 and 2025, or +0.28 °C per decade. This trend is statistically significant.
The number of frost days there went from about 177 to 141 per year over the period.
The hottest day of the period reached 33.0 °C (on 28 July 2010) and the coldest -37.6 °C (on 10 January 1987).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
LammiKanta-Häme
- coords
- 61.08°, 25.02°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
4.4°C
Average daily high
7.7°C
Average daily low
1.0°C
Annual rainfall
634mm
Sunshine / day
7.0h
Mean relative humidity
81%
Average peak wind
15.9km/h
Seasonal range
24.1°C
Frost days (< 0 °C)
159 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
131 d/yr
Annual snowfall
130.9 cm
Average feels-like high
4.5 °C
Average feels-like low
-2.5 °C
Average peak gust
35.5 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
9.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.36 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
33.0 °C
28 July 2010
Coldest day
-37.6 °C
10 January 1987
Wettest day
99 mm
12 August 1972
Windiest day
40.1 km/h
23 January 1995
Strongest gust
95.0 km/h
23 January 1995
Hottest feels-like
33.9 °C
28 July 2010
Coldest feels-like
-43.6 °C
10 January 1987
Snowiest day
16.3 cm
5 April 2022
Sunniest day
18.5 h
27 June 2010
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 0.1 °C | +4.9 °C | 52 mm | +11 mm |
| Feb | -1.8 °C | +2.6 °C | 17 mm | -16 mm |
| Mar | 5.2 °C | +4.8 °C | 24 mm | -10 mm |
| Apr | 9.7 °C | +2.7 °C | 42 mm | +3 mm |
| May | 13.2 °C | -1.2 °C | 40 mm | -8 mm |
| Jun | 17.5 °C | -1.4 °C | 112 mm | +46 mm |
| Jul | 24.6 °C | +3.7 °C | 73 mm | -9 mm |
| Aug | 19.0 °C | -0.3 °C | 89 mm | +9 mm |
| Sep | 17.0 °C | +3.3 °C | 74 mm | +15 mm |
| Oct | 8.6 °C | +1.4 °C | 55 mm | +2 mm |
| Nov | 4.8 °C | +3.4 °C | 39 mm | -13 mm |
| Dec | 2.6 °C | +4.8 °C | 54 mm | +6 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Lammi?
Lammi has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 4.4 °C and it receives 634 mm of precipitation per year.
What is the hottest day ever recorded in Lammi?
The hottest day measured in Lammi between 1940 and 2025 was 28 July 2010, reaching 33.0 °C.
What is the coldest day in Lammi?
The coldest day measured in Lammi between 1940 and 2025 was 10 January 1987, at -37.6 °C.
Does it snow in Lammi?
Yes. Lammi gets on average 130.9 cm of snow per year and has around 159 frost days.
Has the climate of Lammi warmed?
Yes: Lammi warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Lammi?
The wettest day measured in Lammi between 1940 and 2025 was 12 August 1972, with 99 mm of rain in 24 hours.
What was the windiest day in Lammi?
The windiest day measured in Lammi between 1940 and 2025 was 23 January 1995, with winds reaching 40.1 km/h.
What is the warmest month in Lammi?
The warmest month in Lammi is July (16.9 °C on average); the coldest is January (-7.2 °C).
How much does it rain in Lammi?
Lammi receives on average 634 mm of precipitation per year, spread over about 131 rainy days.
Is it sunny in Lammi?
Lammi gets on average 7.0 hours of sunshine per day, roughly 2,555 hours per year over 1940-2025.
What is the biggest single-day snowfall in Lammi?
The heaviest 24-hour snowfall measured in Lammi between 1940 and 2025 was 5 April 2022, with 16.3 cm.
Are there tropical nights in Lammi?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Lammi.
What was the most extreme apparent temperature in Lammi?
In Lammi, between 1940 and 2025, the highest apparent temperature reached 33.9 °C on 28 July 2010, and the lowest was -43.6 °C on 10 January 1987.
Compare Lammi with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Lammi