Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Helsinki Harmaja. The lines show the 2026 daily maximum and minimum. 8 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Helsinki Harmaja, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
7.6 C (45.7 F)
-24.7 C (-12.5 F)
0.4 C (32.7 F)
-16.0 C (3.2 F)
Feb
7.5 C (45.5 F)
-24.3 C (-11.7 F)
1.6 C (34.9 F)
-19.1 C (-2.4 F)
Mar
11.2 C (52.2 F)
-16.4 C (2.5 F)
6.9 C (44.4 F)
-1.6 C (29.1 F)
Apr
16.1 C (61.0 F)
-9.9 C (14.2 F)
13.5 C (56.3 F)
-1.3 C (29.7 F)
May
24.7 C (76.5 F)
-1.1 C (30.0 F)
17.9 C (64.2 F)
3.5 C (38.3 F)
Jun
27.4 C (81.3 F)
3.4 C (38.1 F)
22.6 C (72.7 F)
8.7 C (47.7 F)
Jul
29.3 C (84.7 F)
7.6 C (45.7 F)
25.4 C (77.7 F)
8.3 C (46.9 F)
Aug
27.0 C (80.6 F)
7.9 C (46.2 F)
20.0 C (68.0 F)
10.5 C (50.9 F)
Sep
21.9 C (71.4 F)
2.1 C (35.8 F)
n/a
n/a
Oct
16.0 C (60.8 F)
-5.7 C (21.7 F)
n/a
n/a
Nov
13.0 C (55.4 F)
-13.0 C (8.6 F)
n/a
n/a
Dec
8.7 C (47.7 F)
-20.5 C (-4.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Helsinki Harmaja still stand. 2020 holds the most, with 98.
Standing records at Helsinki Harmaja by the year they were set
Year set
Standing records
1993
44
1994
46
1995
52
1996
75
1997
40
1998
62
1999
37
2000
23
2001
36
2002
71
2003
57
2004
14
2005
26
2006
62
2007
28
2008
19
2009
18
2010
49
2011
36
2012
24
2013
27
2014
45
2015
36
2016
26
2017
27
2018
54
2019
42
2020
98
2021
62
2022
42
2023
41
2024
76
2025
56
2026
13
Period of Record Coverage
1993 to 2026
Complete yearUnder 90 percent of days
34 years of record at Helsinki Harmaja, 1993 to 2026. 2 years have data for under 90 percent of days and are left out of rankings: 1993, 2026.
Cooler than the station meanWarmer than the station mean
One stripe for each of 32 complete years at Helsinki Harmaja, 1994 to 2025. Blue stripes are years cooler than the station's own mean of 6.4 C (43.5 F); red stripes are warmer. The coolest year was 1996, at 4.5 C (40.1 F), and the warmest was 2020, at 8.4 C (47.1 F). The strongest colour marks a difference of 2.0 C (3.6 F).
Annual mean temperature at Helsinki Harmaja as warming stripes, 1994 to 2025
Year
Annual mean temperature
Difference from the station mean
1994
4.9 C
-1.53 C
1995
6.0 C
-0.43 C
1996
4.5 C
-1.91 C
1997
6.0 C
-0.37 C
1998
5.2 C
-1.20 C
1999
5.9 C
-0.47 C
2000
7.1 C
+0.64 C
2001
6.0 C
-0.43 C
2002
6.1 C
-0.31 C
2003
5.1 C
-1.28 C
2004
6.0 C
-0.43 C
2005
6.6 C
+0.15 C
2006
6.2 C
-0.18 C
2007
6.8 C
+0.37 C
2008
7.4 C
+0.95 C
2009
6.2 C
-0.21 C
2010
4.9 C
-1.51 C
2011
6.8 C
+0.37 C
2012
5.8 C
-0.57 C
2013
6.6 C
+0.20 C
2014
7.0 C
+0.60 C
2015
7.5 C
+1.13 C
2016
6.4 C
+0.01 C
2017
6.4 C
-0.03 C
2018
6.8 C
+0.34 C
2019
7.1 C
+0.65 C
2020
8.4 C
+2.00 C
2021
6.3 C
-0.14 C
2022
7.0 C
+0.54 C
2023
6.8 C
+0.36 C
2024
7.5 C
+1.09 C
2025
8.0 C
+1.62 C
The annual mean temperature here has risen by 0.6 C (0.4 to 0.9) per decade over 1994 to 2025. In Fahrenheit: 1.2 F (0.7 to 1.6) per decade. The slope is a straight line fitted to 32 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Helsinki Harmaja
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.6 C (0.4 to 0.9) per decade
1.2 F (0.7 to 1.6) per decade
1994 to 2025
32
Rise
Mean daily maximum
0.6 C (0.3 to 0.8) per decade
1.0 F (0.6 to 1.4) per decade
1994 to 2025
32
Rise
Mean daily minimum
0.7 C (0.4 to 1.0) per decade
1.3 F (0.8 to 1.8) per decade
1994 to 2025
32
Rise
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1993 to 2026
Yearly extremes at Helsinki Harmaja: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
29.3 C (84.7 F)
2021
25.3 C (77.5 F)
34
Coldest night (TNn)
-24.7 C (-12.5 F)
1999
-17.9 C (-0.3 F)
34
Hottest day (TXx)
The hottest day of the year at Helsinki Harmaja, 1993 to 2026. The record is 29.3 C (84.7 F) in 2021, marked on the chart; the median year is 25.3 C (77.5 F).
Hottest day (TXx) at Helsinki Harmaja by year
Year
Hottest day (TXx)
1993
21.3 C (70.3 F)
1994
24.6 C (76.3 F)
1995
24.7 C (76.5 F)
1996
25.1 C (77.2 F)
1997
26.7 C (80.1 F)
1998
21.8 C (71.2 F)
1999
25.5 C (77.9 F)
2000
23.5 C (74.3 F)
2001
28.8 C (83.8 F)
2002
26.1 C (79.0 F)
2003
27.2 C (81.0 F)
2004
23.4 C (74.1 F)
2005
26.4 C (79.5 F)
2006
24.5 C (76.1 F)
2007
24.4 C (75.9 F)
2008
25.6 C (78.1 F)
2009
25.7 C (78.3 F)
2010
27.7 C (81.9 F)
2011
27.4 C (81.3 F)
2012
23.4 C (74.1 F)
2013
23.2 C (73.8 F)
2014
27.3 C (81.1 F)
2015
22.3 C (72.1 F)
2016
22.5 C (72.5 F)
2017
20.9 C (69.6 F)
2018
27.6 C (81.7 F)
2019
28.5 C (83.3 F)
2020
24.3 C (75.7 F)
2021
29.3 C (84.7 F)
2022
26.8 C (80.2 F)
2023
25.0 C (77.0 F)
2024
23.7 C (74.7 F)
2025
27.6 C (81.7 F)
2026
25.4 C (77.7 F)
Coldest night (TNn)
The coldest night of the year at Helsinki Harmaja, 1993 to 2026. The record is -24.7 C (-12.5 F) in 1999, marked on the chart; the median year is -17.9 C (-0.3 F).
Coldest night (TNn) at Helsinki Harmaja by year
Year
Coldest night (TNn)
1993
-16.4 C (2.5 F)
1994
-22.7 C (-8.9 F)
1995
-19.1 C (-2.4 F)
1996
-19.3 C (-2.7 F)
1997
-16.5 C (2.3 F)
1998
-17.9 C (-0.2 F)
1999
-24.7 C (-12.5 F)
2000
-15.4 C (4.3 F)
2001
-21.5 C (-6.7 F)
2002
-18.8 C (-1.8 F)
2003
-24.2 C (-11.6 F)
2004
-17.3 C (0.9 F)
2005
-15.3 C (4.5 F)
2006
-20.9 C (-5.6 F)
2007
-19.7 C (-3.5 F)
2008
-8.8 C (16.2 F)
2009
-13.0 C (8.6 F)
2010
-21.8 C (-7.2 F)
2011
-22.5 C (-8.5 F)
2012
-24.3 C (-11.7 F)
2013
-18.0 C (-0.4 F)
2014
-14.9 C (5.2 F)
2015
-11.3 C (11.7 F)
2016
-20.4 C (-4.7 F)
2017
-16.2 C (2.8 F)
2018
-19.2 C (-2.6 F)
2019
-13.9 C (7.0 F)
2020
-6.2 C (20.8 F)
2021
-18.4 C (-1.1 F)
2022
-13.9 C (7.0 F)
2023
-12.4 C (9.7 F)
2024
-16.6 C (2.1 F)
2025
-10.4 C (13.3 F)
2026
-19.1 C (-2.4 F)
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
32 years with a frost
Across 32 years with a frost, the median last spring frost at Helsinki Harmaja falls on 16 April and the median first autumn frost on 1 November, which leaves a median of 201 days between them.
Fitted over all years, the growing season changes by +8.1 days per decade at this station.
Frost dates and growing season at Helsinki Harmaja
Measure
Median, all years
Earliest period
Recent period (1996 to 2025)
Recent against earliest
Fitted trend
Last spring frost
16 April
n/a
15 April
n/a
-5.0 days per decade
First autumn frost
1 November
n/a
3 November
n/a
+3.1 days per decade
Growing days
201 days
n/a
202 days
n/a
+8.1 days per decade
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Download the Data
Data for Helsinki Harmaja standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Helsinki Harmaja threshold days by year: CSV or JSON. Field meanings are on the data page.
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-13 (13 October 2026). Records are computed by this site and are not official.