Heilbronn Weather Records (GME00123562)

Record envelope, standing records and threshold days for Heilbronn (GME00123562), Germany, with 57 years of record.

Key Facts for Heilbronn

Heilbronn (GME00123562) is a weather station in Germany at 49.15 latitude and 9.23 longitude, 167 m (548 ft) above sea level.
The station reports from 1947 to 2003, 57 years of record.
1,464 records set at Heilbronn still stand.
Records are tracked for tmax, tmin, prcp, snwd: an element needs 30 years of data to be eligible.
Heilbronn set a daily record low minimum temperature of -3.5 C (25.7 F) on 28 October 2003.

About the Station

Location: Germany, 49.15 latitude, 9.23 longitude.
Elevation: 167 m (548 ft).
Period of record: 1947 to 2003, 57 years.
Eligible elements: tmax, tmin, prcp, snwd.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Heilbronn. 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 Heilbronn, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	18.5 C (65.3 F)	-20.4 C (-4.7 F)	n/a	n/a
Feb	21.0 C (69.8 F)	-21.9 C (-7.4 F)	n/a	n/a
Mar	26.1 C (79.0 F)	-13.0 C (8.6 F)	n/a	n/a
Apr	31.0 C (87.8 F)	-5.6 C (21.9 F)	n/a	n/a
May	32.8 C (91.0 F)	-1.6 C (29.1 F)	n/a	n/a
Jun	37.0 C (98.6 F)	1.6 C (34.9 F)	n/a	n/a
Jul	37.7 C (99.9 F)	5.6 C (42.1 F)	n/a	n/a
Aug	38.5 C (101.3 F)	4.4 C (39.9 F)	n/a	n/a
Sep	32.5 C (90.5 F)	0.9 C (33.6 F)	n/a	n/a
Oct	30.0 C (86.0 F)	-4.6 C (23.7 F)	n/a	n/a
Nov	20.0 C (68.0 F)	-9.9 C (14.2 F)	n/a	n/a
Dec	18.0 C (64.4 F)	-17.6 C (0.3 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Heilbronn still stand. 1962 holds the most, with 51.

Standing records at Heilbronn by the year they were set
Year set	Standing records
1947	24
1948	23
1949	31
1950	18
1951	10
1952	28
1953	27
1954	14
1955	19
1956	39
1957	19
1958	29
1959	20
1960	27
1961	39
1962	51
1963	41
1964	29
1965	20
1966	30
1967	29
1968	32
1969	28
1970	13
1971	30
1972	22
1973	23
1974	28
1975	15
1976	31
1977	26
1978	16
1979	25
1980	27
1981	30
1982	10
1983	32
1984	15
1985	37
1986	31
1987	29
1988	9
1989	37
1990	22
1991	26
1992	18
1993	34
1994	25
1995	24
1996	18
1997	23
1998	31
1999	14
2000	28
2001	15
2002	25
2003	48

All-Time Record Progression

3 new records

3 all-time records were set at Heilbronn between 17 June 1978 and 13 August 2003. Each dot is a new record.

When Heilbronn set new all-time records
Date	Kind	Detail
1978-06-17	Record daily precipitation	Record daily precipitation 81.0 mm (3.2 in)
1985-01-08	Record low maximum temperature	Record low maximum temperature -13.4 C (7.9 F)
2003-08-13	Record high maximum temperature	Record high maximum temperature 38.5 C (101.3 F)

Wettest Day of Each Month

Jun: 81.0 mm (3.2 in)

The wettest day on record for each calendar month at Heilbronn. The most was 81.0 mm (3.2 in) on 17 June 1978.

Record daily precipitation for each month at Heilbronn
Month	Record daily precipitation (mm)	Date
Jan	42.7 mm (1.7 in)	14 January 1948
Feb	63.9 mm (2.5 in)	25 February 1997
Mar	32.3 mm (1.3 in)	20 March 2002
Apr	36.6 mm (1.4 in)	30 April 1959
May	51.2 mm (2.0 in)	29 May 1980
Jun	81.0 mm (3.2 in)	17 June 1978
Jul	56.1 mm (2.2 in)	22 July 1995
Aug	67.9 mm (2.7 in)	29 August 1968
Sep	50.5 mm (2.0 in)	16 September 1976
Oct	51.3 mm (2.0 in)	6 October 1982
Nov	43.0 mm (1.7 in)	15 November 1947
Dec	52.1 mm (2.1 in)	20 December 1993

Period of Record Coverage

1947 to 2003

57 years of record at Heilbronn, 1947 to 2003. 2 years have data for under 90 percent of days and are left out of rankings: 1947, 2003.

Days with data per year at Heilbronn
Year	Days with data	Share of year	Complete
1947	184	50%	No
1948	366	100%	Yes
1949	365	100%	Yes
1950	365	100%	Yes
1951	365	100%	Yes
1952	366	100%	Yes
1953	365	100%	Yes
1954	365	100%	Yes
1955	365	100%	Yes
1956	366	100%	Yes
1957	365	100%	Yes
1958	365	100%	Yes
1959	365	100%	Yes
1960	366	100%	Yes
1961	365	100%	Yes
1962	365	100%	Yes
1963	365	100%	Yes
1964	366	100%	Yes
1965	365	100%	Yes
1966	365	100%	Yes
1967	365	100%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	365	100%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	365	100%	Yes
1975	365	100%	Yes
1976	366	100%	Yes
1977	365	100%	Yes
1978	365	100%	Yes
1979	365	100%	Yes
1980	366	100%	Yes
1981	365	100%	Yes
1982	365	100%	Yes
1983	365	100%	Yes
1984	366	100%	Yes
1985	365	100%	Yes
1986	365	100%	Yes
1987	365	100%	Yes
1988	366	100%	Yes
1989	365	100%	Yes
1990	365	100%	Yes
1991	365	100%	Yes
1992	366	100%	Yes
1993	365	100%	Yes
1994	365	100%	Yes
1995	365	100%	Yes
1996	366	100%	Yes
1997	365	100%	Yes
1998	365	100%	Yes
1999	365	100%	Yes
2000	366	100%	Yes
2001	365	100%	Yes
2002	365	100%	Yes
2003	304	83%	No

Latest Records

Latest records at Heilbronn
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
28 October 2003	Heilbronn, DE	daily low min	-3.5 C (25.7 F)	1.0 C (1.8 F)	29 years	15 of 100 (Routine)
24 October 2003	Heilbronn, DE	daily low min	-3.0 C (26.6 F)	0.5 C (0.9 F)	37 years	17 of 100 (Routine)
18 October 2003	Heilbronn, DE	daily low min	-1.8 C (28.8 F)	0.8 C (1.4 F)	32 years	16 of 100 (Routine)
8 October 2003	Heilbronn, DE	daily rain	10.2 mm (0.4 in)	2.2 mm (0.09 in)	52 years	20 of 100 (Routine)
7 October 2003	Heilbronn, DE	daily rain	34.1 mm (1.3 in)	8.0 mm (0.31 in)	46 years	33 of 100 (Routine)
7 September 2003	Heilbronn, DE	daily rain	17.3 mm (0.7 in)	2.9 mm (0.11 in)	53 years	20 of 100 (Routine)
4 September 2003	Heilbronn, DE	daily low min	5.5 C (41.9 F)	0.8 C (1.4 F)	24 years	14 of 100 (Routine)
19 August 2003	Heilbronn, DE	daily high min	19.4 C (66.9 F)	1.3 C (2.3 F)	16 years	13 of 100 (Routine)
18 August 2003	Heilbronn, DE	daily high min	19.9 C (67.8 F)	0.9 C (1.6 F)	16 years	12 of 100 (Routine)
14 August 2003	Heilbronn, DE	daily high min	20.6 C (69.1 F)	2.1 C (3.8 F)	49 years	26 of 100 (Routine)
13 August 2003	Heilbronn, DE	all-time high max	38.5 C (101.3 F)	0.8 C (1.4 F)	56 years	42 of 100 (Notable)
13 August 2003	Heilbronn, DE	daily high min	19.2 C (66.6 F)	0.2 C (0.4 F)	4 years	6 of 100 (Routine)
12 August 2003	Heilbronn, DE	monthly high max (Tie)	37.5 C (99.5 F)	tie	0 years	3 of 100 (Routine)
10 August 2003	Heilbronn, DE	daily high min	19.4 C (66.9 F)	1.9 C (3.4 F)	30 years	20 of 100 (Routine)
10 August 2003	Heilbronn, DE	daily high max	35.6 C (96.1 F)	1.0 C (1.8 F)	4 years	8 of 100 (Routine)
9 August 2003	Heilbronn, DE	daily high min	20.0 C (68.0 F)	0.3 C (0.5 F)	53 years	22 of 100 (Routine)
9 August 2003	Heilbronn, DE	monthly high max	37.5 C (99.5 F)	0.1 C (0.2 F)	0 years	15 of 100 (Routine)
8 August 2003	Heilbronn, DE	monthly high max	37.4 C (99.3 F)	0.4 C (0.7 F)	4 years	16 of 100 (Routine)
7 August 2003	Heilbronn, DE	daily high max	36.7 C (98.1 F)	1.2 C (2.2 F)	12 years	10 of 100 (Routine)
6 August 2003	Heilbronn, DE	monthly high min	21.5 C (70.7 F)	0.2 C (0.4 F)	11 years	18 of 100 (Routine)

Climate Trend

55 complete years, 1948 to 2002

One stripe for each of 55 complete years at Heilbronn, 1948 to 2002. Blue stripes are years cooler than the station's own mean of 10.4 C (50.6 F); red stripes are warmer. The coolest year was 1956, at 8.7 C (47.7 F), and the warmest was 1994, at 11.9 C (53.4 F). The strongest colour marks a difference of 1.7 C (3.1 F).

Annual mean temperature at Heilbronn as warming stripes, 1948 to 2002
Year	Annual mean temperature	Difference from the station mean
1948	10.6 C	+0.27 C
1949	11.0 C	+0.62 C
1950	10.6 C	+0.27 C
1951	10.7 C	+0.39 C
1952	10.4 C	0.00 C
1953	10.6 C	+0.24 C
1954	9.7 C	-0.63 C
1955	9.5 C	-0.86 C
1956	8.7 C	-1.63 C
1957	10.3 C	-0.02 C
1958	10.1 C	-0.24 C
1959	10.7 C	+0.38 C
1960	10.3 C	-0.03 C
1961	10.9 C	+0.58 C
1962	9.2 C	-1.12 C
1963	8.8 C	-1.52 C
1964	10.3 C	-0.08 C
1965	9.6 C	-0.80 C
1966	10.7 C	+0.38 C
1967	10.5 C	+0.18 C
1968	9.8 C	-0.56 C
1969	9.7 C	-0.67 C
1970	9.9 C	-0.47 C
1971	10.1 C	-0.28 C
1972	9.6 C	-0.75 C
1973	9.9 C	-0.49 C
1974	10.6 C	+0.25 C
1975	10.6 C	+0.24 C
1976	10.5 C	+0.17 C
1977	10.5 C	+0.19 C
1978	9.5 C	-0.88 C
1979	10.0 C	-0.38 C
1980	9.5 C	-0.82 C
1981	10.1 C	-0.26 C
1982	10.6 C	+0.23 C
1983	10.8 C	+0.47 C
1984	9.8 C	-0.57 C
1985	9.4 C	-0.99 C
1986	10.0 C	-0.34 C
1987	9.6 C	-0.73 C
1988	11.0 C	+0.68 C
1989	11.1 C	+0.76 C
1990	11.3 C	+0.95 C
1991	10.4 C	+0.01 C
1992	11.2 C	+0.89 C
1993	10.7 C	+0.31 C
1994	11.9 C	+1.56 C
1995	11.0 C	+0.60 C
1996	9.5 C	-0.90 C
1997	10.8 C	+0.40 C
1998	11.1 C	+0.70 C
1999	11.4 C	+1.04 C
2000	11.7 C	+1.39 C
2001	11.1 C	+0.75 C
2002	11.6 C	+1.20 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.3) per decade over 1948 to 2002. In Fahrenheit: 0.3 F (0.1 to 0.5) per decade. The slope is a straight line fitted to 55 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Heilbronn
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.2 C (0.1 to 0.3) per decade	0.3 F (0.1 to 0.5) per decade	1948 to 2002	55	Rise
Mean daily maximum	0.2 C (0.1 to 0.3) per decade	0.3 F (0.1 to 0.6) per decade	1948 to 2002	55	Rise
Mean daily minimum	0.16 C (0.04 to 0.27) per decade	0.3 F (0.1 to 0.5) per decade	1948 to 2002	55	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

1947 to 2003

Yearly extremes at Heilbronn: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.5 C (101.3 F)	2003	34.2 C (93.6 F)	57
Coldest night (TNn)	-21.9 C (-7.4 F)	1956	-12.4 C (9.7 F)	57
Wettest day (Rx1day)	81.0 mm (3.2 in)	1978	36.4 mm (1.4 in)	57
Wettest five days (Rx5day)	107.2 mm (4.2 in)	1968	60.8 mm (2.4 in)	57
Longest dry spell (CDD)	43 days	1953	22 days	57

Hottest day (TXx)

The hottest day of the year at Heilbronn, 1947 to 2003. The record is 38.5 C (101.3 F) in 2003, marked on the chart; the median year is 34.2 C (93.6 F).

Hottest day (TXx) at Heilbronn by year
Year	Hottest day (TXx)
1947	37.7 C (99.9 F)
1948	31.8 C (89.2 F)
1949	34.2 C (93.6 F)
1950	35.1 C (95.2 F)
1951	32.9 C (91.2 F)
1952	37.3 C (99.1 F)
1953	32.6 C (90.7 F)
1954	32.0 C (89.6 F)
1955	32.7 C (90.9 F)
1956	30.7 C (87.3 F)
1957	36.2 C (97.2 F)
1958	32.1 C (89.8 F)
1959	34.6 C (94.3 F)
1960	31.2 C (88.2 F)
1961	32.4 C (90.3 F)
1962	34.8 C (94.6 F)
1963	35.4 C (95.7 F)
1964	36.2 C (97.2 F)
1965	33.0 C (91.4 F)
1966	35.1 C (95.2 F)
1967	32.6 C (90.7 F)
1968	32.4 C (90.3 F)
1969	33.4 C (92.1 F)
1970	32.0 C (89.6 F)
1971	35.9 C (96.6 F)
1972	33.0 C (91.4 F)
1973	33.5 C (92.3 F)
1974	35.2 C (95.4 F)
1975	32.2 C (90.0 F)
1976	35.0 C (95.0 F)
1977	32.1 C (89.8 F)
1978	30.3 C (86.5 F)
1979	31.6 C (88.9 F)
1980	31.8 C (89.2 F)
1981	30.6 C (87.1 F)
1982	32.2 C (90.0 F)
1983	37.0 C (98.6 F)
1984	37.0 C (98.6 F)
1985	34.8 C (94.6 F)
1986	35.0 C (95.0 F)
1987	31.6 C (88.9 F)
1988	32.4 C (90.3 F)
1989	35.3 C (95.5 F)
1990	35.1 C (95.2 F)
1991	35.5 C (95.9 F)
1992	35.6 C (96.1 F)
1993	34.0 C (93.2 F)
1994	36.0 C (96.8 F)
1995	35.5 C (95.9 F)
1996	32.6 C (90.7 F)
1997	33.5 C (92.3 F)
1998	37.0 C (98.6 F)
1999	34.2 C (93.6 F)
2000	35.0 C (95.0 F)
2001	35.4 C (95.7 F)
2002	37.0 C (98.6 F)
2003	38.5 C (101.3 F)

Coldest night (TNn)

The coldest night of the year at Heilbronn, 1947 to 2003. The record is -21.9 C (-7.4 F) in 1956, marked on the chart; the median year is -12.4 C (9.7 F).

Coldest night (TNn) at Heilbronn by year
Year	Coldest night (TNn)
1947	-11.7 C (10.9 F)
1948	-13.2 C (8.2 F)
1949	-12.0 C (10.4 F)
1950	-12.2 C (10.0 F)
1951	-10.6 C (12.9 F)
1952	-13.0 C (8.6 F)
1953	-13.0 C (8.6 F)
1954	-15.7 C (3.7 F)
1955	-10.6 C (12.9 F)
1956	-21.9 C (-7.4 F)
1957	-12.0 C (10.4 F)
1958	-10.0 C (14.0 F)
1959	-10.5 C (13.1 F)
1960	-15.7 C (3.7 F)
1961	-12.0 C (10.4 F)
1962	-16.4 C (2.5 F)
1963	-18.5 C (-1.3 F)
1964	-12.9 C (8.8 F)
1965	-11.4 C (11.5 F)
1966	-16.1 C (3.0 F)
1967	-12.6 C (9.3 F)
1968	-20.4 C (-4.7 F)
1969	-14.5 C (5.9 F)
1970	-11.0 C (12.2 F)
1971	-17.2 C (1.0 F)
1972	-12.8 C (9.0 F)
1973	-17.6 C (0.3 F)
1974	-3.8 C (25.2 F)
1975	-9.6 C (14.7 F)
1976	-14.6 C (5.7 F)
1977	-7.4 C (18.7 F)
1978	-12.4 C (9.7 F)
1979	-15.7 C (3.7 F)
1980	-10.8 C (12.6 F)
1981	-10.5 C (13.1 F)
1982	-14.1 C (6.6 F)
1983	-8.9 C (16.0 F)
1984	-9.4 C (15.1 F)
1985	-20.2 C (-4.4 F)
1986	-14.6 C (5.7 F)
1987	-18.1 C (-0.6 F)
1988	-9.0 C (15.8 F)
1989	-9.6 C (14.7 F)
1990	-8.2 C (17.2 F)
1991	-12.6 C (9.3 F)
1992	-9.6 C (14.7 F)
1993	-11.7 C (10.9 F)
1994	-8.9 C (16.0 F)
1995	-10.7 C (12.7 F)
1996	-15.1 C (4.8 F)
1997	-14.4 C (6.1 F)
1998	-11.6 C (11.1 F)
1999	-11.6 C (11.1 F)
2000	-12.4 C (9.7 F)
2001	-16.1 C (3.0 F)
2002	-15.0 C (5.0 F)
2003	-11.5 C (11.3 F)

Wettest day (Rx1day)

The wettest day of the year at Heilbronn, 1947 to 2003. The record is 81.0 mm (3.2 in) in 1978, marked on the chart; the median year is 36.4 mm (1.4 in).

Wettest day (Rx1day) at Heilbronn by year
Year	Wettest day (Rx1day)
1947	43.8 mm (1.7 in)
1948	42.7 mm (1.7 in)
1949	20.5 mm (0.8 in)
1950	40.9 mm (1.6 in)
1951	49.1 mm (1.9 in)
1952	27.9 mm (1.1 in)
1953	49.7 mm (2.0 in)
1954	23.2 mm (0.9 in)
1955	23.5 mm (0.9 in)
1956	33.8 mm (1.3 in)
1957	27.1 mm (1.1 in)
1958	31.5 mm (1.2 in)
1959	36.6 mm (1.4 in)
1960	19.4 mm (0.8 in)
1961	24.1 mm (0.9 in)
1962	23.0 mm (0.9 in)
1963	37.2 mm (1.5 in)
1964	40.3 mm (1.6 in)
1965	36.7 mm (1.4 in)
1966	35.8 mm (1.4 in)
1967	40.9 mm (1.6 in)
1968	67.9 mm (2.7 in)
1969	26.8 mm (1.1 in)
1970	39.1 mm (1.5 in)
1971	24.3 mm (1.0 in)
1972	22.9 mm (0.9 in)
1973	33.3 mm (1.3 in)
1974	20.5 mm (0.8 in)
1975	25.9 mm (1.0 in)
1976	50.5 mm (2.0 in)
1977	22.9 mm (0.9 in)
1978	81.0 mm (3.2 in)
1979	28.5 mm (1.1 in)
1980	51.2 mm (2.0 in)
1981	34.2 mm (1.3 in)
1982	51.3 mm (2.0 in)
1983	34.8 mm (1.4 in)
1984	40.0 mm (1.6 in)
1985	31.6 mm (1.2 in)
1986	31.2 mm (1.2 in)
1987	34.5 mm (1.4 in)
1988	22.8 mm (0.9 in)
1989	42.3 mm (1.7 in)
1990	38.5 mm (1.5 in)
1991	41.4 mm (1.6 in)
1992	41.5 mm (1.6 in)
1993	52.1 mm (2.1 in)
1994	42.5 mm (1.7 in)
1995	56.1 mm (2.2 in)
1996	30.5 mm (1.2 in)
1997	63.9 mm (2.5 in)
1998	49.6 mm (2.0 in)
1999	36.4 mm (1.4 in)
2000	45.8 mm (1.8 in)
2001	32.0 mm (1.3 in)
2002	43.8 mm (1.7 in)
2003	34.1 mm (1.3 in)

Wettest five days (Rx5day)

The wettest five days of the year at Heilbronn, 1947 to 2003. The record is 107.2 mm (4.2 in) in 1968, marked on the chart; the median year is 60.8 mm (2.4 in).

Wettest five days (Rx5day) at Heilbronn by year
Year	Wettest five days (Rx5day)
1947	85.1 mm (3.4 in)
1948	78.5 mm (3.1 in)
1949	49.6 mm (2.0 in)
1950	56.6 mm (2.2 in)
1951	62.7 mm (2.5 in)
1952	71.5 mm (2.8 in)
1953	85.1 mm (3.4 in)
1954	43.9 mm (1.7 in)
1955	56.2 mm (2.2 in)
1956	48.2 mm (1.9 in)
1957	50.9 mm (2.0 in)
1958	54.9 mm (2.2 in)
1959	56.0 mm (2.2 in)
1960	47.0 mm (1.9 in)
1961	61.7 mm (2.4 in)
1962	57.1 mm (2.2 in)
1963	51.3 mm (2.0 in)
1964	74.0 mm (2.9 in)
1965	86.6 mm (3.4 in)
1966	60.9 mm (2.4 in)
1967	54.6 mm (2.1 in)
1968	107.2 mm (4.2 in)
1969	50.0 mm (2.0 in)
1970	66.7 mm (2.6 in)
1971	50.1 mm (2.0 in)
1972	58.8 mm (2.3 in)
1973	64.4 mm (2.5 in)
1974	51.6 mm (2.0 in)
1975	47.5 mm (1.9 in)
1976	77.6 mm (3.1 in)
1977	38.7 mm (1.5 in)
1978	97.1 mm (3.8 in)
1979	42.7 mm (1.7 in)
1980	64.0 mm (2.5 in)
1981	59.5 mm (2.3 in)
1982	71.2 mm (2.8 in)
1983	88.4 mm (3.5 in)
1984	54.9 mm (2.2 in)
1985	49.4 mm (1.9 in)
1986	67.2 mm (2.6 in)
1987	61.5 mm (2.4 in)
1988	59.4 mm (2.3 in)
1989	51.7 mm (2.0 in)
1990	64.0 mm (2.5 in)
1991	50.3 mm (2.0 in)
1992	75.2 mm (3.0 in)
1993	104.1 mm (4.1 in)
1994	63.0 mm (2.5 in)
1995	56.2 mm (2.2 in)
1996	72.5 mm (2.9 in)
1997	72.2 mm (2.8 in)
1998	90.0 mm (3.5 in)
1999	69.8 mm (2.7 in)
2000	54.5 mm (2.1 in)
2001	60.8 mm (2.4 in)
2002	88.7 mm (3.5 in)
2003	59.3 mm (2.3 in)

Longest dry spell (CDD)

The longest dry spell of the year at Heilbronn, 1947 to 2003. The record is 43 days in 1953, marked on the chart; the median year is 22 days.

Longest dry spell (CDD) at Heilbronn by year
Year	Longest dry spell (CDD)
1947	32 days
1948	31 days
1949	23 days
1950	16 days
1951	23 days
1952	33 days
1953	43 days
1954	20 days
1955	22 days
1956	27 days
1957	19 days
1958	24 days
1959	32 days
1960	15 days
1961	18 days
1962	36 days
1963	18 days
1964	16 days
1965	30 days
1966	28 days
1967	16 days
1968	23 days
1969	22 days
1970	14 days
1971	21 days
1972	24 days
1973	22 days
1974	26 days
1975	18 days
1976	37 days
1977	21 days
1978	20 days
1979	22 days
1980	18 days
1981	16 days
1982	14 days
1983	37 days
1984	25 days
1985	26 days
1986	30 days
1987	13 days
1988	12 days
1989	20 days
1990	25 days
1991	26 days
1992	14 days
1993	17 days
1994	18 days
1995	12 days
1996	30 days
1997	24 days
1998	33 days
1999	14 days
2000	18 days
2001	17 days
2002	21 days
2003	23 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

55 years with a frost

Across 55 years with a frost, the median last spring frost at Heilbronn falls on 14 April and the median first autumn frost on 28 October, which leaves a median of 200 days between them.

Fitted over all years, the growing season changes by +0.5 days per decade at this station.

Frost dates and growing season at Heilbronn
Measure	Median, all years	Earliest period	Recent period (1973 to 2002)	Recent against earliest	Fitted trend
Last spring frost	14 April	n/a	19 April	n/a	+1.1 days per decade
First autumn frost	28 October	n/a	3 November	n/a	+1.6 days per decade
Growing days	200 days	n/a	202 days	n/a	+0.5 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, 1948 to 2002

A day with at least 35.4 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 76.7 mm (3.0 in) of rain is expected about once in 100 years.

Rainfall return levels at Heilbronn: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	35.4 mm (1.4 in)
5 years	46.7 mm (1.8 in)
10 years	54.1 mm (2.1 in)
25 years	63.3 mm (2.5 in)
50 years	70.0 mm (2.8 in)
100 years	76.7 mm (3.0 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 1948 to 2002.

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: 81.0 mm (3.2 in) in 1978; 67.9 mm (2.7 in) in 1968; 63.9 mm (2.5 in) in 1997.

Station Changes

1 suspected

One change was suspected in the annual mean temperature of Heilbronn, at 1957. Each is measured against neighbouring stations.

Relative to 5 neighbouring stations, the station's annual mean temperature from 1957 ran 0.1 C (0.2 F) lower than in the years before (possible change).

Suspected changes in the annual mean temperature at Heilbronn, against neighbouring stations
Year	Shift (C)	Shift (F)	Strength	Neighbours
1957	-0.1	-0.2	possible	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.

Download the Data

Data for Heilbronn standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Heilbronn 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.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).