Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Bonn-Friesdorf. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Bonn-Friesdorf, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
16.1 C (61.0 F)
-23.0 C (-9.4 F)
n/a
n/a
Feb
18.7 C (65.7 F)
-20.2 C (-4.4 F)
n/a
n/a
Mar
25.7 C (78.3 F)
-11.8 C (10.8 F)
n/a
n/a
Apr
30.7 C (87.3 F)
-5.3 C (22.5 F)
n/a
n/a
May
32.0 C (89.6 F)
-3.0 C (26.6 F)
n/a
n/a
Jun
37.9 C (100.2 F)
1.8 C (35.2 F)
n/a
n/a
Jul
36.9 C (98.4 F)
5.6 C (42.1 F)
n/a
n/a
Aug
35.7 C (96.3 F)
4.0 C (39.2 F)
n/a
n/a
Sep
34.6 C (94.3 F)
-0.5 C (31.1 F)
n/a
n/a
Oct
27.5 C (81.5 F)
-4.9 C (23.2 F)
n/a
n/a
Nov
21.0 C (69.8 F)
-9.0 C (15.8 F)
n/a
n/a
Dec
17.5 C (63.5 F)
-18.3 C (-0.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Bonn-Friesdorf still stand. 1947 holds the most, with 50.
Standing records at Bonn-Friesdorf by the year they were set
Year set
Standing records
1933
40
1934
22
1935
30
1936
30
1937
21
1938
43
1939
33
1940
45
1941
30
1942
29
1946
6
1947
50
1948
36
1949
37
1950
21
1951
12
1952
26
1953
31
1954
13
1955
25
1956
50
1957
31
1958
25
1959
16
1960
23
1961
34
1962
38
1963
28
1964
35
1965
21
1966
39
1967
25
1968
31
1969
22
1970
9
1971
32
1972
19
1973
20
1974
28
1975
16
1976
31
1977
23
1978
25
1979
27
1980
24
1981
32
1982
9
1983
33
1984
18
1985
41
1986
39
1998
34
1999
6
All-Time Record Progression
2 new records
2 all-time records were set at Bonn-Friesdorf between 8 July 1970 and 31 July 1984. Each dot is a new record.
When Bonn-Friesdorf set new all-time records
Date
Kind
Detail
1970-07-08
Record daily precipitation
Record daily precipitation 73.8 mm (2.9 in)
1984-07-31
Record high minimum temperature
Record high minimum temperature 22.5 C (72.5 F)
Wettest Day of Each Month
Jul: 73.8 mm (2.9 in)
The wettest day on record for each calendar month at Bonn-Friesdorf. The most was 73.8 mm (2.9 in) on 8 July 1970.
Record daily precipitation for each month at Bonn-Friesdorf
Month
Record daily precipitation (mm)
Date
Jan
28.2 mm (1.1 in)
13 January 1968
Feb
43.5 mm (1.7 in)
6 February 1984
Mar
34.3 mm (1.4 in)
24 March 1957
Apr
54.9 mm (2.2 in)
17 April 1936
May
44.2 mm (1.7 in)
29 May 1954
Jun
57.0 mm (2.2 in)
10 June 1953
Jul
73.8 mm (2.9 in)
8 July 1970
Aug
73.7 mm (2.9 in)
11 August 1936
Sep
43.6 mm (1.7 in)
10 September 1972
Oct
42.4 mm (1.7 in)
23 October 1982
Nov
32.0 mm (1.3 in)
22 November 1984
Dec
31.5 mm (1.2 in)
21 December 1960
Period of Record Coverage
1932 to 1999
Complete yearUnder 90 percent of days
54 years of record at Bonn-Friesdorf, 1932 to 1999. 3 years have data for under 90 percent of days and are left out of rankings: 1932, 1946, 1999.
Cooler than the station meanWarmer than the station mean
One stripe for each of 50 complete years at Bonn-Friesdorf, 1933 to 1998. Blue stripes are years cooler than the station's own mean of 10.3 C (50.5 F); red stripes are warmer. The coolest year was 1940, at 8.7 C (47.7 F), and the warmest was 1982, at 11.3 C (52.3 F). The strongest colour marks a difference of 1.6 C (2.9 F).
Annual mean temperature at Bonn-Friesdorf as warming stripes, 1933 to 1998
Year
Annual mean temperature
Difference from the station mean
1933
9.3 C
-0.95 C
1934
11.0 C
+0.67 C
1935
10.3 C
+0.04 C
1936
10.2 C
-0.13 C
1937
10.4 C
+0.15 C
1938
10.5 C
+0.17 C
1939
10.0 C
-0.25 C
1940
8.7 C
-1.58 C
1941
9.4 C
-0.86 C
1942
9.4 C
-0.92 C
1948
10.8 C
+0.51 C
1949
10.9 C
+0.60 C
1950
10.3 C
+0.04 C
1951
10.4 C
+0.13 C
1952
9.9 C
-0.40 C
1953
10.6 C
+0.34 C
1954
9.8 C
-0.53 C
1955
9.5 C
-0.76 C
1956
8.7 C
-1.56 C
1957
10.5 C
+0.22 C
1958
10.2 C
-0.08 C
1959
11.1 C
+0.85 C
1960
10.5 C
+0.26 C
1961
10.9 C
+0.61 C
1962
9.1 C
-1.21 C
1963
9.0 C
-1.25 C
1964
10.3 C
+0.02 C
1965
9.7 C
-0.55 C
1966
10.7 C
+0.42 C
1967
10.9 C
+0.58 C
1968
10.2 C
-0.13 C
1969
10.2 C
-0.04 C
1970
10.2 C
-0.10 C
1971
10.7 C
+0.38 C
1972
10.1 C
-0.16 C
1973
10.6 C
+0.34 C
1974
11.1 C
+0.79 C
1975
11.1 C
+0.86 C
1976
11.1 C
+0.86 C
1977
10.9 C
+0.61 C
1978
10.1 C
-0.21 C
1979
10.1 C
-0.23 C
1980
10.3 C
0.00 C
1981
10.5 C
+0.26 C
1982
11.3 C
+1.01 C
1983
11.3 C
+0.99 C
1984
10.4 C
+0.07 C
1985
9.7 C
-0.62 C
1986
10.2 C
-0.07 C
1998
11.3 C
+0.99 C
The annual mean temperature here has risen by 0.14 C (0.03 to 0.25) per decade over 1933 to 1998. In Fahrenheit: 0.3 F (0.1 to 0.4) per decade. The slope is a straight line fitted to 50 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Bonn-Friesdorf
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.14 C (0.03 to 0.25) per decade
0.3 F (0.1 to 0.4) per decade
1933 to 1998
50
Rise
Mean daily maximum
-0.03 C (-0.16 to 0.10) per decade
-0.1 F (-0.3 to 0.2) per decade
1933 to 1998
50
Not clearly different from zero
Mean daily minimum
0.3 C (0.2 to 0.4) per decade
0.6 F (0.4 to 0.7) per decade
1933 to 1998
50
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
1931 to 1999
Yearly extremes at Bonn-Friesdorf: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
37.9 C (100.2 F)
1947
32.8 C (91.0 F)
54
Coldest night (TNn)
-23.0 C (-9.4 F)
1942
-11.4 C (11.4 F)
54
Wettest day (Rx1day)
73.8 mm (2.9 in)
1970
32.1 mm (1.3 in)
57
Wettest five days (Rx5day)
119.2 mm (4.7 in)
1984
50.5 mm (2.0 in)
57
Longest dry spell (CDD)
40 days
1959
20 days
57
Hottest day (TXx)
The hottest day of the year at Bonn-Friesdorf, 1931 to 1999. The record is 37.9 C (100.2 F) in 1947, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Bonn-Friesdorf by year
Year
Hottest day (TXx)
1931
n/a
1932
21.9 C (71.4 F)
1933
35.0 C (95.0 F)
1934
31.9 C (89.4 F)
1935
31.7 C (89.1 F)
1936
31.5 C (88.7 F)
1937
34.6 C (94.3 F)
1938
34.0 C (93.2 F)
1939
33.5 C (92.3 F)
1940
29.7 C (85.5 F)
1941
33.5 C (92.3 F)
1942
33.4 C (92.1 F)
1943
n/a
1944
n/a
1946
15.7 C (60.3 F)
1947
37.9 C (100.2 F)
1948
33.0 C (91.4 F)
1949
34.1 C (93.4 F)
1950
32.3 C (90.1 F)
1951
31.7 C (89.1 F)
1952
36.9 C (98.4 F)
1953
33.0 C (91.4 F)
1954
31.5 C (88.7 F)
1955
30.5 C (86.9 F)
1956
29.6 C (85.3 F)
1957
35.7 C (96.3 F)
1958
29.5 C (85.1 F)
1959
36.7 C (98.1 F)
1960
30.3 C (86.5 F)
1961
33.0 C (91.4 F)
1962
31.2 C (88.2 F)
1963
32.0 C (89.6 F)
1964
36.2 C (97.2 F)
1965
29.1 C (84.4 F)
1966
34.0 C (93.2 F)
1967
31.3 C (88.3 F)
1968
32.5 C (90.5 F)
1969
34.0 C (93.2 F)
1970
30.6 C (87.1 F)
1971
31.3 C (88.3 F)
1972
33.1 C (91.6 F)
1973
33.3 C (91.9 F)
1974
35.2 C (95.4 F)
1975
33.0 C (91.4 F)
1976
35.6 C (96.1 F)
1977
31.8 C (89.2 F)
1978
32.0 C (89.6 F)
1979
30.6 C (87.1 F)
1980
31.1 C (88.0 F)
1981
31.2 C (88.2 F)
1982
32.3 C (90.1 F)
1983
35.1 C (95.2 F)
1984
33.6 C (92.5 F)
1985
33.0 C (91.4 F)
1986
35.6 C (96.1 F)
1998
35.7 C (96.3 F)
1999
16.1 C (61.0 F)
Coldest night (TNn)
The coldest night of the year at Bonn-Friesdorf, 1931 to 1999. The record is -23.0 C (-9.4 F) in 1942, marked on the chart; the median year is -11.4 C (11.4 F).
Coldest night (TNn) at Bonn-Friesdorf by year
Year
Coldest night (TNn)
1931
n/a
1932
-5.5 C (22.1 F)
1933
-14.5 C (5.9 F)
1934
-13.6 C (7.5 F)
1935
-10.6 C (12.9 F)
1936
-11.0 C (12.2 F)
1937
-7.3 C (18.9 F)
1938
-18.3 C (-0.9 F)
1939
-12.0 C (10.4 F)
1940
-19.5 C (-3.1 F)
1941
-12.0 C (10.4 F)
1942
-23.0 C (-9.4 F)
1943
n/a
1944
n/a
1946
-15.3 C (4.5 F)
1947
-17.2 C (1.0 F)
1948
-12.0 C (10.4 F)
1949
-9.6 C (14.7 F)
1950
-14.8 C (5.4 F)
1951
-6.5 C (20.3 F)
1952
-8.5 C (16.7 F)
1953
-13.0 C (8.6 F)
1954
-15.5 C (4.1 F)
1955
-12.3 C (9.9 F)
1956
-20.2 C (-4.4 F)
1957
-7.5 C (18.5 F)
1958
-10.5 C (13.1 F)
1959
-7.0 C (19.4 F)
1960
-17.0 C (1.4 F)
1961
-10.8 C (12.6 F)
1962
-11.1 C (12.0 F)
1963
-18.8 C (-1.8 F)
1964
-12.0 C (10.4 F)
1965
-9.0 C (15.8 F)
1966
-13.1 C (8.4 F)
1967
-9.7 C (14.5 F)
1968
-13.0 C (8.6 F)
1969
-12.8 C (9.0 F)
1970
-10.0 C (14.0 F)
1971
-11.8 C (10.8 F)
1972
-10.0 C (14.0 F)
1973
-9.3 C (15.3 F)
1974
-4.5 C (23.9 F)
1975
-8.1 C (17.4 F)
1976
-10.4 C (13.3 F)
1977
-5.9 C (21.4 F)
1978
-14.0 C (6.8 F)
1979
-16.1 C (3.0 F)
1980
-10.5 C (13.1 F)
1981
-9.4 C (15.1 F)
1982
-15.0 C (5.0 F)
1983
-7.5 C (18.5 F)
1984
-7.2 C (19.0 F)
1985
-16.6 C (2.1 F)
1986
-15.5 C (4.1 F)
1998
-9.9 C (14.2 F)
1999
-8.8 C (16.2 F)
Wettest day (Rx1day)
The wettest day of the year at Bonn-Friesdorf, 1931 to 1999. The record is 73.8 mm (2.9 in) in 1970, marked on the chart; the median year is 32.1 mm (1.3 in).
Wettest day (Rx1day) at Bonn-Friesdorf by year
Year
Wettest day (Rx1day)
1931
25.2 mm (1.0 in)
1932
15.0 mm (0.6 in)
1933
26.5 mm (1.0 in)
1934
45.4 mm (1.8 in)
1935
30.7 mm (1.2 in)
1936
73.7 mm (2.9 in)
1937
42.7 mm (1.7 in)
1938
35.7 mm (1.4 in)
1939
26.7 mm (1.1 in)
1940
23.4 mm (0.9 in)
1941
41.0 mm (1.6 in)
1942
31.6 mm (1.2 in)
1943
24.0 mm (0.9 in)
1944
33.2 mm (1.3 in)
1946
9.4 mm (0.37 in)
1947
32.1 mm (1.3 in)
1948
27.0 mm (1.1 in)
1949
38.9 mm (1.5 in)
1950
25.8 mm (1.0 in)
1951
29.7 mm (1.2 in)
1952
61.3 mm (2.4 in)
1953
69.6 mm (2.7 in)
1954
44.2 mm (1.7 in)
1955
40.2 mm (1.6 in)
1956
34.3 mm (1.4 in)
1957
34.3 mm (1.4 in)
1958
29.7 mm (1.2 in)
1959
31.8 mm (1.3 in)
1960
31.5 mm (1.2 in)
1961
54.7 mm (2.2 in)
1962
31.5 mm (1.2 in)
1963
27.8 mm (1.1 in)
1964
23.4 mm (0.9 in)
1965
35.2 mm (1.4 in)
1966
45.5 mm (1.8 in)
1967
32.0 mm (1.3 in)
1968
69.1 mm (2.7 in)
1969
47.6 mm (1.9 in)
1970
73.8 mm (2.9 in)
1971
25.1 mm (1.0 in)
1972
43.6 mm (1.7 in)
1973
27.5 mm (1.1 in)
1974
22.8 mm (0.9 in)
1975
34.4 mm (1.4 in)
1976
16.6 mm (0.7 in)
1977
29.2 mm (1.1 in)
1978
40.2 mm (1.6 in)
1979
34.3 mm (1.4 in)
1980
37.2 mm (1.5 in)
1981
36.2 mm (1.4 in)
1982
42.4 mm (1.7 in)
1983
17.3 mm (0.7 in)
1984
43.5 mm (1.7 in)
1985
17.9 mm (0.7 in)
1986
33.1 mm (1.3 in)
1998
26.6 mm (1.0 in)
1999
16.0 mm (0.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Bonn-Friesdorf, 1931 to 1999. The record is 119.2 mm (4.7 in) in 1984, marked on the chart; the median year is 50.5 mm (2.0 in).
Wettest five days (Rx5day) at Bonn-Friesdorf by year
Year
Wettest five days (Rx5day)
1931
45.0 mm (1.8 in)
1932
23.6 mm (0.9 in)
1933
47.3 mm (1.9 in)
1934
76.8 mm (3.0 in)
1935
57.0 mm (2.2 in)
1936
77.7 mm (3.1 in)
1937
49.2 mm (1.9 in)
1938
49.2 mm (1.9 in)
1939
47.7 mm (1.9 in)
1940
45.9 mm (1.8 in)
1941
50.4 mm (2.0 in)
1942
62.3 mm (2.5 in)
1943
34.1 mm (1.3 in)
1944
54.3 mm (2.1 in)
1946
19.8 mm (0.8 in)
1947
48.9 mm (1.9 in)
1948
44.5 mm (1.8 in)
1949
60.0 mm (2.4 in)
1950
42.2 mm (1.7 in)
1951
63.5 mm (2.5 in)
1952
74.4 mm (2.9 in)
1953
87.6 mm (3.4 in)
1954
78.5 mm (3.1 in)
1955
57.6 mm (2.3 in)
1956
56.7 mm (2.2 in)
1957
62.8 mm (2.5 in)
1958
46.9 mm (1.8 in)
1959
39.4 mm (1.6 in)
1960
44.8 mm (1.8 in)
1961
113.5 mm (4.5 in)
1962
47.9 mm (1.9 in)
1963
39.5 mm (1.6 in)
1964
57.8 mm (2.3 in)
1965
76.0 mm (3.0 in)
1966
73.1 mm (2.9 in)
1967
40.0 mm (1.6 in)
1968
98.6 mm (3.9 in)
1969
109.4 mm (4.3 in)
1970
81.8 mm (3.2 in)
1971
49.7 mm (2.0 in)
1972
62.4 mm (2.5 in)
1973
32.5 mm (1.3 in)
1974
38.7 mm (1.5 in)
1975
45.9 mm (1.8 in)
1976
34.2 mm (1.3 in)
1977
50.5 mm (2.0 in)
1978
42.8 mm (1.7 in)
1979
52.7 mm (2.1 in)
1980
50.2 mm (2.0 in)
1981
62.5 mm (2.5 in)
1982
66.9 mm (2.6 in)
1983
52.0 mm (2.0 in)
1984
119.2 mm (4.7 in)
1985
40.7 mm (1.6 in)
1986
60.0 mm (2.4 in)
1998
65.1 mm (2.6 in)
1999
42.3 mm (1.7 in)
Longest dry spell (CDD)
The longest dry spell of the year at Bonn-Friesdorf, 1931 to 1999. The record is 40 days in 1959, marked on the chart; the median year is 20 days.
Longest dry spell (CDD) at Bonn-Friesdorf by year
Year
Longest dry spell (CDD)
1931
23 days
1932
18 days
1933
24 days
1934
24 days
1935
15 days
1936
20 days
1937
28 days
1938
36 days
1939
16 days
1940
17 days
1941
24 days
1942
13 days
1943
19 days
1944
14 days
1946
12 days
1947
32 days
1948
22 days
1949
22 days
1950
12 days
1951
30 days
1952
17 days
1953
33 days
1954
16 days
1955
21 days
1956
19 days
1957
15 days
1958
14 days
1959
40 days
1960
22 days
1961
16 days
1962
16 days
1963
29 days
1964
15 days
1965
13 days
1966
16 days
1967
17 days
1968
24 days
1969
35 days
1970
12 days
1971
26 days
1972
23 days
1973
22 days
1974
22 days
1975
19 days
1976
22 days
1977
18 days
1978
24 days
1979
20 days
1980
19 days
1981
18 days
1982
17 days
1983
17 days
1984
24 days
1985
21 days
1986
22 days
1998
22 days
1999
7 days
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
50 years with a frost
Across 50 years with a frost, the median last spring frost at Bonn-Friesdorf falls on 14 April and the median first autumn frost on 6 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 Bonn-Friesdorf
Measure
Median, all years
Earliest period
Recent period (1958 to 1998)
Recent against earliest
Fitted trend
Last spring frost
14 April
n/a
13 April
n/a
-2.7 days per decade
First autumn frost
6 November
n/a
10 November
n/a
+5.4 days per decade
Growing days
201 days
n/a
219 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.
Rainfall Return Levels
55 years, 1931 to 1998
A day with at least 32.9 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 84.2 mm (3.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Bonn-Friesdorf: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
32.9 mm (1.3 in)
5 years
44.6 mm (1.8 in)
10 years
53.1 mm (2.1 in)
25 years
64.8 mm (2.6 in)
50 years
74.2 mm (2.9 in)
100 years
84.2 mm (3.3 in)
Longer than the 55 years of record
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 55 years of values from 1931 to 1998.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 73.8 mm (2.9 in) in 1970; 73.7 mm (2.9 in) in 1936; 69.6 mm (2.7 in) in 1953.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Bonn-Friesdorf, at 1969. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1969 ran 0.1 C (0.1 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Bonn-Friesdorf, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1969
+0.1
+0.1
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
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Data for Bonn-Friesdorf standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Bonn-Friesdorf 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.