Duluth Harbor STN Weather Records (USC00212246)

Record envelope, standing records and threshold days for Duluth Harbor STN (USC00212246), Minnesota, United States, with 72 years of record.

Key Facts for Duluth Harbor STN

Duluth Harbor STN (USC00212246) is a weather station in Minnesota, United States at 46.77 latitude and -92.09 longitude, 186 m (610 ft) above sea level.
The station reports from 1933 to 2004, 72 years of record.
1,464 records set at Duluth Harbor STN still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Duluth Harbor STN set a daily record high maximum temperature of 23.3 C (73.9 F) on 27 September 2004.

About the Station

Location: Minnesota, United States, 46.77 latitude, -92.09 longitude.
Elevation: 186 m (610 ft).
Period of record: 1933 to 2004, 72 years.
Eligible elements: tmax, tmin, prcp, snow, 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 Duluth Harbor STN. 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 Duluth Harbor STN, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	10.6 C (51.1 F)	-35.6 C (-32.1 F)	n/a	n/a
Feb	12.2 C (54.0 F)	-38.3 C (-36.9 F)	n/a	n/a
Mar	19.4 C (66.9 F)	-33.3 C (-27.9 F)	n/a	n/a
Apr	27.2 C (81.0 F)	-17.2 C (1.0 F)	n/a	n/a
May	32.2 C (90.0 F)	-6.1 C (21.0 F)	n/a	n/a
Jun	32.8 C (91.0 F)	0.0 C (32.0 F)	n/a	n/a
Jul	36.1 C (97.0 F)	2.8 C (37.0 F)	n/a	n/a
Aug	36.1 C (97.0 F)	0.0 C (32.0 F)	n/a	n/a
Sep	33.3 C (91.9 F)	-1.7 C (28.9 F)	n/a	n/a
Oct	29.4 C (84.9 F)	-10.0 C (14.0 F)	n/a	n/a
Nov	19.4 C (66.9 F)	-23.3 C (-9.9 F)	n/a	n/a
Dec	13.9 C (57.0 F)	-32.8 C (-27.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Duluth Harbor STN still stand. 2002 holds the most, with 59.

Standing records at Duluth Harbor STN by the year they were set
Year set	Standing records
1960	14
1961	33
1962	39
1963	53
1964	36
1965	39
1966	33
1967	31
1968	33
1969	24
1970	21
1971	14
1972	45
1973	22
1974	27
1975	24
1976	55
1977	32
1978	15
1979	35
1980	32
1981	48
1982	21
1983	46
1984	29
1985	25
1986	24
1987	49
1988	22
1989	32
1990	17
1991	46
1992	22
1993	22
1994	30
1995	27
1996	52
1997	29
1998	26
1999	24
2000	22
2001	24
2002	59
2003	54
2004	57

All-Time Record Progression

4 new records

4 all-time records were set at Duluth Harbor STN between 7 January 1994 and 3 February 1996. Each dot is a new record.

When Duluth Harbor STN set new all-time records
Date	Kind	Detail
1994-01-07	Record daily snowfall	Record daily snowfall 50.8 cm (20.0 in)
1996-02-02	Record low minimum temperature	Record low minimum temperature -37.8 C (-36.0 F)
1996-02-03	Record low maximum temperature	Record low maximum temperature -27.8 C (-18.0 F)
1996-02-03	Record low minimum temperature	Record low minimum temperature -38.3 C (-36.9 F)

Wettest Day of Each Month

Sep: 110.5 mm (4.4 in)

The wettest day on record for each calendar month at Duluth Harbor STN. The most was 110.5 mm (4.4 in) on 7 September 1964.

Record daily precipitation for each month at Duluth Harbor STN
Month	Record daily precipitation (mm)	Date
Jan	34.3 mm (1.4 in)	10 January 1975
Feb	23.9 mm (0.9 in)	25 February 1977
Mar	44.2 mm (1.7 in)	28 March 1977
Apr	49.8 mm (2.0 in)	23 April 1968
May	52.3 mm (2.1 in)	24 May 1989
Jun	63.5 mm (2.5 in)	10 June 1986
Jul	52.8 mm (2.1 in)	14 July 1968
Aug	69.3 mm (2.7 in)	25 August 1990
Sep	110.5 mm (4.4 in)	7 September 1964
Oct	63.5 mm (2.5 in)	6 October 1982
Nov	41.9 mm (1.6 in)	9 November 1978
Dec	37.3 mm (1.5 in)	11 December 1983

Period of Record Coverage

1960 to 2004

45 years of record at Duluth Harbor STN, 1960 to 2004. 9 years have data for under 90 percent of days and are left out of rankings: 1960, 1988, 1990, 1991, 1993, 1995, 1998, 2000 and others.

Days with data per year at Duluth Harbor STN
Year	Days with data	Share of year	Complete
1960	306	84%	No
1961	365	100%	Yes
1962	365	100%	Yes
1963	363	99%	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	364	100%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	364	100%	Yes
1974	365	100%	Yes
1975	365	100%	Yes
1976	365	100%	Yes
1977	358	98%	Yes
1978	356	98%	Yes
1979	360	99%	Yes
1980	334	91%	Yes
1981	363	99%	Yes
1982	346	95%	Yes
1983	364	100%	Yes
1984	366	100%	Yes
1985	364	100%	Yes
1986	363	99%	Yes
1987	346	95%	Yes
1988	266	73%	No
1989	347	95%	Yes
1990	295	81%	No
1991	320	88%	No
1992	353	96%	Yes
1993	288	79%	No
1994	331	91%	Yes
1995	322	88%	No
1996	364	99%	Yes
1997	355	97%	Yes
1998	321	88%	No
1999	364	100%	Yes
2000	304	83%	No
2001	333	91%	Yes
2002	363	99%	Yes
2003	364	100%	Yes
2004	273	75%	No

Latest Records

Latest records at Duluth Harbor STN
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
27 September 2004	Duluth Harbor STN, US	daily high max	23.3 C (73.9 F)	1.6 C (2.9 F)	25 years	14 of 100 (Routine)
21 September 2004	Duluth Harbor STN, US	daily high max	25.6 C (78.1 F)	2.3 C (4.1 F)	38 years	19 of 100 (Routine)
18 September 2004	Duluth Harbor STN, US	daily low max	11.7 C (53.1 F)	0.5 C (0.9 F)	12 years	8 of 100 (Routine)
17 September 2004	Duluth Harbor STN, US	daily low min	1.1 C (34.0 F)	2.2 C (4.0 F)	2 years	9 of 100 (Routine)
12 September 2004	Duluth Harbor STN, US	daily low min	2.2 C (36.0 F)	2.8 C (5.0 F)	40 years	23 of 100 (Routine)
11 September 2004	Duluth Harbor STN, US	daily low min	3.9 C (39.0 F)	0.5 C (0.9 F)	40 years	17 of 100 (Routine)
3 September 2004	Duluth Harbor STN, US	daily low max (Tie)	14.4 C (57.9 F)	tie	4 years	1 of 100 (Routine)
2 September 2004	Duluth Harbor STN, US	daily low max	12.8 C (55.0 F)	0.5 C (0.9 F)	19 years	10 of 100 (Routine)
30 August 2004	Duluth Harbor STN, US	daily low min	6.7 C (44.1 F)	1.6 C (2.9 F)	1 year	9 of 100 (Routine)
30 August 2004	Duluth Harbor STN, US	daily low max (Tie)	13.3 C (55.9 F)	tie	39 years	3 of 100 (Routine)
29 August 2004	Duluth Harbor STN, US	daily low min	1.7 C (35.1 F)	6.6 C (11.9 F)	28 years	34 of 100 (Routine)
29 August 2004	Duluth Harbor STN, US	daily low max (Tie)	13.3 C (55.9 F)	tie	39 years	3 of 100 (Routine)
28 August 2004	Duluth Harbor STN, US	daily low min	3.9 C (39.0 F)	2.2 C (4.0 F)	39 years	22 of 100 (Routine)
27 August 2004	Duluth Harbor STN, US	daily low min	3.9 C (39.0 F)	3.9 C (7.0 F)	22 years	23 of 100 (Routine)
27 August 2004	Duluth Harbor STN, US	daily low max (Tie)	15.6 C (60.1 F)	tie	36 years	3 of 100 (Routine)
25 August 2004	Duluth Harbor STN, US	daily low min	2.8 C (37.0 F)	5.5 C (9.9 F)	27 years	30 of 100 (Routine)
24 August 2004	Duluth Harbor STN, US	daily low min	4.4 C (39.9 F)	3.4 C (6.1 F)	2 years	15 of 100 (Routine)
23 August 2004	Duluth Harbor STN, US	daily low min	5.0 C (41.0 F)	2.2 C (4.0 F)	2 years	11 of 100 (Routine)
22 August 2004	Duluth Harbor STN, US	monthly low min	0.0 C (32.0 F)	1.1 C (2.0 F)	2 years	17 of 100 (Routine)
21 August 2004	Duluth Harbor STN, US	monthly low min (Tie)	1.1 C (34.0 F)	tie	2 years	3 of 100 (Routine)

Climate Trend

32 complete years, 1961 to 2003

One stripe for each of 32 complete years at Duluth Harbor STN, 1961 to 2003. Blue stripes are years cooler than the station's own mean of 4.5 C (40.1 F); red stripes are warmer. The coolest year was 1972, at 2.2 C (35.9 F), and the warmest was 1987, at 7.3 C (45.2 F). The strongest colour marks a difference of 2.9 C (5.2 F).

Annual mean temperature at Duluth Harbor STN as warming stripes, 1961 to 2003
Year	Annual mean temperature	Difference from the station mean
1961	5.6 C	+1.13 C
1962	4.1 C	-0.41 C
1963	4.9 C	+0.42 C
1964	4.9 C	+0.43 C
1965	3.6 C	-0.86 C
1966	4.4 C	-0.11 C
1967	4.2 C	-0.34 C
1968	4.8 C	+0.32 C
1969	5.1 C	+0.61 C
1970	4.3 C	-0.19 C
1971	4.2 C	-0.29 C
1972	2.2 C	-2.31 C
1973	5.4 C	+0.85 C
1974	4.3 C	-0.17 C
1975	4.8 C	+0.26 C
1976	4.2 C	-0.29 C
1977	4.5 C	-0.04 C
1978	4.3 C	-0.19 C
1979	3.2 C	-1.35 C
1981	6.1 C	+1.62 C
1983	5.3 C	+0.80 C
1984	5.0 C	+0.46 C
1985	3.7 C	-0.78 C
1986	5.0 C	+0.54 C
1987	7.3 C	+2.83 C
1989	3.3 C	-1.19 C
1992	4.8 C	+0.28 C
1996	2.2 C	-2.27 C
1997	4.1 C	-0.40 C
1999	5.9 C	+1.40 C
2002	4.4 C	-0.12 C
2003	3.9 C	-0.62 C

The fitted trend in annual mean temperature here over 1961 to 2003 is -0.03 C (-0.35 to 0.28) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.6 to 0.5) 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 Duluth Harbor STN
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.03 C (-0.35 to 0.28) per decade	-0.1 F (-0.6 to 0.5) per decade	1961 to 2003	32	Not clearly different from zero
Mean daily maximum	0.1 C (-0.3 to 0.4) per decade	0.1 F (-0.5 to 0.6) per decade	1961 to 2003	32	Not clearly different from zero
Mean daily minimum	-0.1 C (-0.5 to 0.2) per decade	-0.2 F (-0.9 to 0.4) per decade	1961 to 2003	32	Not clearly different from zero

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

1933 to 2004

Yearly extremes at Duluth Harbor STN: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	36.1 C (97.0 F)	1980	32.2 C (90.0 F)	45
Coldest night (TNn)	-38.3 C (-36.9 F)	1996	-29.4 C (-20.9 F)	45
Wettest day (Rx1day)	110.5 mm (4.4 in)	1964	51.1 mm (2.0 in)	38
Wettest five days (Rx5day)	145.8 mm (5.7 in)	1964	80.5 mm (3.2 in)	38
Longest dry spell (CDD)	61 days	1976	26 days	38

Hottest day (TXx)

The hottest day of the year at Duluth Harbor STN, 1933 to 2004. The record is 36.1 C (97.0 F) in 1980, marked on the chart; the median year is 32.2 C (90.0 F).

Hottest day (TXx) at Duluth Harbor STN by year
Year	Hottest day (TXx)
1933	n/a
1960	31.7 C (89.1 F)
1961	32.8 C (91.0 F)
1962	28.9 C (84.0 F)
1963	32.8 C (91.0 F)
1964	35.6 C (96.1 F)
1965	32.2 C (90.0 F)
1966	33.9 C (93.0 F)
1967	28.3 C (82.9 F)
1968	28.9 C (84.0 F)
1969	31.7 C (89.1 F)
1970	30.6 C (87.1 F)
1971	31.1 C (88.0 F)
1972	32.2 C (90.0 F)
1973	31.7 C (89.1 F)
1974	32.8 C (91.0 F)
1975	31.7 C (89.1 F)
1976	33.9 C (93.0 F)
1977	31.7 C (89.1 F)
1978	31.1 C (88.0 F)
1979	29.4 C (84.9 F)
1980	36.1 C (97.0 F)
1981	31.7 C (89.1 F)
1982	28.9 C (84.0 F)
1983	33.9 C (93.0 F)
1984	32.8 C (91.0 F)
1985	29.4 C (84.9 F)
1986	32.2 C (90.0 F)
1987	32.8 C (91.0 F)
1988	32.2 C (90.0 F)
1989	31.1 C (88.0 F)
1990	28.9 C (84.0 F)
1991	33.3 C (91.9 F)
1992	30.6 C (87.1 F)
1993	29.4 C (84.9 F)
1994	28.9 C (84.0 F)
1995	32.8 C (91.0 F)
1996	29.4 C (84.9 F)
1997	32.8 C (91.0 F)
1998	33.9 C (93.0 F)
1999	35.6 C (96.1 F)
2000	32.2 C (90.0 F)
2001	36.1 C (97.0 F)
2002	33.9 C (93.0 F)
2003	33.3 C (91.9 F)
2004	33.3 C (91.9 F)

Coldest night (TNn)

The coldest night of the year at Duluth Harbor STN, 1933 to 2004. The record is -38.3 C (-36.9 F) in 1996, marked on the chart; the median year is -29.4 C (-20.9 F).

Coldest night (TNn) at Duluth Harbor STN by year
Year	Coldest night (TNn)
1933	n/a
1960	-23.9 C (-11.0 F)
1961	-30.0 C (-22.0 F)
1962	-33.3 C (-27.9 F)
1963	-32.2 C (-26.0 F)
1964	-26.1 C (-15.0 F)
1965	-32.2 C (-26.0 F)
1966	-35.6 C (-32.1 F)
1967	-31.7 C (-25.1 F)
1968	-32.2 C (-26.0 F)
1969	-23.3 C (-9.9 F)
1970	-30.0 C (-22.0 F)
1971	-28.9 C (-20.0 F)
1972	-34.4 C (-29.9 F)
1973	-26.7 C (-16.1 F)
1974	-30.0 C (-22.0 F)
1975	-27.8 C (-18.0 F)
1976	-29.4 C (-20.9 F)
1977	-34.4 C (-29.9 F)
1978	-26.1 C (-15.0 F)
1979	-31.1 C (-24.0 F)
1980	-29.4 C (-20.9 F)
1981	-26.7 C (-16.1 F)
1982	-21.1 C (-6.0 F)
1983	-32.8 C (-27.0 F)
1984	-32.2 C (-26.0 F)
1985	-32.8 C (-27.0 F)
1986	-27.2 C (-17.0 F)
1987	-28.9 C (-20.0 F)
1988	-31.1 C (-24.0 F)
1989	-32.8 C (-27.0 F)
1990	-28.3 C (-18.9 F)
1991	-26.7 C (-16.1 F)
1992	-28.9 C (-20.0 F)
1993	-28.3 C (-18.9 F)
1994	-35.6 C (-32.1 F)
1995	-28.9 C (-20.0 F)
1996	-38.3 C (-36.9 F)
1997	-31.7 C (-25.1 F)
1998	-26.1 C (-15.0 F)
1999	-25.6 C (-14.1 F)
2000	-25.0 C (-13.0 F)
2001	-25.0 C (-13.0 F)
2002	-22.2 C (-8.0 F)
2003	-25.0 C (-13.0 F)
2004	-31.7 C (-25.1 F)

Wettest day (Rx1day)

The wettest day of the year at Duluth Harbor STN, 1933 to 2004. The record is 110.5 mm (4.4 in) in 1964, marked on the chart; the median year is 51.1 mm (2.0 in).

Wettest day (Rx1day) at Duluth Harbor STN by year
Year	Wettest day (Rx1day)
1933	n/a
1960	40.1 mm (1.6 in)
1961	37.8 mm (1.5 in)
1962	46.2 mm (1.8 in)
1963	29.5 mm (1.2 in)
1964	110.5 mm (4.4 in)
1965	39.6 mm (1.6 in)
1966	56.9 mm (2.2 in)
1967	54.6 mm (2.1 in)
1968	52.8 mm (2.1 in)
1969	36.1 mm (1.4 in)
1970	52.8 mm (2.1 in)
1971	47.2 mm (1.9 in)
1972	89.2 mm (3.5 in)
1973	51.3 mm (2.0 in)
1974	41.7 mm (1.6 in)
1975	42.7 mm (1.7 in)
1976	41.9 mm (1.6 in)
1977	44.2 mm (1.7 in)
1978	68.6 mm (2.7 in)
1979	50.8 mm (2.0 in)
1980	59.7 mm (2.4 in)
1981	53.3 mm (2.1 in)
1982	63.5 mm (2.5 in)
1983	51.6 mm (2.0 in)
1984	45.0 mm (1.8 in)
1985	53.3 mm (2.1 in)
1986	63.5 mm (2.5 in)
1987	52.1 mm (2.1 in)
1988	53.3 mm (2.1 in)
1989	52.3 mm (2.1 in)
1990	89.7 mm (3.5 in)
1991	48.3 mm (1.9 in)
1992	51.3 mm (2.0 in)
1993	29.2 mm (1.1 in)
1994	12.7 mm (0.5 in)
1995	0.0 mm (0.00 in)
1996	0.0 mm (0.00 in)
1997	0.0 mm (0.00 in)
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a

Wettest five days (Rx5day)

The wettest five days of the year at Duluth Harbor STN, 1933 to 2004. The record is 145.8 mm (5.7 in) in 1964, marked on the chart; the median year is 80.5 mm (3.2 in).

Wettest five days (Rx5day) at Duluth Harbor STN by year
Year	Wettest five days (Rx5day)
1933	n/a
1960	62.5 mm (2.5 in)
1961	55.7 mm (2.2 in)
1962	89.0 mm (3.5 in)
1963	36.1 mm (1.4 in)
1964	145.8 mm (5.7 in)
1965	70.4 mm (2.8 in)
1966	83.6 mm (3.3 in)
1967	93.4 mm (3.7 in)
1968	79.8 mm (3.1 in)
1969	54.4 mm (2.1 in)
1970	83.1 mm (3.3 in)
1971	92.7 mm (3.6 in)
1972	103.6 mm (4.1 in)
1973	109.0 mm (4.3 in)
1974	78.0 mm (3.1 in)
1975	59.7 mm (2.4 in)
1976	55.4 mm (2.2 in)
1977	58.6 mm (2.3 in)
1978	139.7 mm (5.5 in)
1979	105.4 mm (4.1 in)
1980	109.2 mm (4.3 in)
1981	102.3 mm (4.0 in)
1982	92.4 mm (3.6 in)
1983	71.1 mm (2.8 in)
1984	84.0 mm (3.3 in)
1985	86.0 mm (3.4 in)
1986	68.8 mm (2.7 in)
1987	78.5 mm (3.1 in)
1988	81.2 mm (3.2 in)
1989	61.3 mm (2.4 in)
1990	103.7 mm (4.1 in)
1991	43.2 mm (1.7 in)
1992	86.1 mm (3.4 in)
1993	81.2 mm (3.2 in)
1994	7.6 mm (0.30 in)
1995	0.0 mm (0.00 in)
1996	0.0 mm (0.00 in)
1997	0.0 mm (0.00 in)
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a

Longest dry spell (CDD)

The longest dry spell of the year at Duluth Harbor STN, 1933 to 2004. The record is 61 days in 1976, marked on the chart; the median year is 26 days.

Longest dry spell (CDD) at Duluth Harbor STN by year
Year	Longest dry spell (CDD)
1933	n/a
1960	32 days
1961	30 days
1962	28 days
1963	21 days
1964	24 days
1965	18 days
1966	24 days
1967	23 days
1968	32 days
1969	32 days
1970	22 days
1971	16 days
1972	14 days
1973	20 days
1974	22 days
1975	20 days
1976	61 days
1977	27 days
1978	24 days
1979	38 days
1980	29 days
1981	61 days
1982	22 days
1983	26 days
1984	29 days
1985	26 days
1986	25 days
1987	23 days
1988	34 days
1989	31 days
1990	37 days
1991	30 days
1992	24 days
1993	22 days
1994	12 days
1995	30 days
1996	29 days
1997	11 days
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a

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 Duluth Harbor STN falls on 1 May and the median first autumn frost on 16 October, which leaves a median of 172 days between them.

Fitted over all years, the growing season changes by -4.4 days per decade at this station.

Frost dates and growing season at Duluth Harbor STN
Measure	Median, all years	Earliest period	Recent period (1963 to 2003)	Recent against earliest	Fitted trend
Last spring frost	1 May	n/a	1 May	n/a	+1.2 days per decade
First autumn frost	16 October	n/a	16 October	n/a	-3.2 days per decade
Growing days	172 days	n/a	172 days	n/a	-4.4 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 Duluth Harbor STN standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Duluth Harbor STN 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 2026-10-15 (15 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).