Plum Island Weather Records (USC00476667)

Record envelope, standing records and threshold days for Plum Island (USC00476667), Wisconsin, United States, with 37 years of record.

Key Facts for Plum Island

Plum Island (USC00476667) is a weather station in Wisconsin, United States at 45.32 latitude and -86.95 longitude, 179 m (588 ft) above sea level.
The station reports from 1908 to 1944, 37 years of record.
1,464 records set at Plum Island still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Plum Island set a daily record high minimum temperature of 15.6 C (60.1 F) on 31 May 1944.

About the Station

Location: Wisconsin, United States, 45.32 latitude, -86.95 longitude.
Elevation: 179 m (588 ft).
Period of record: 1908 to 1944, 37 years.
Eligible elements: tmax, tmin, prcp, snow.

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 Plum Island. 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 Plum Island, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	12.2 C (54.0 F)	-32.2 C (-26.0 F)	n/a	n/a
Feb	12.8 C (55.0 F)	-32.2 C (-26.0 F)	n/a	n/a
Mar	21.7 C (71.1 F)	-27.8 C (-18.0 F)	n/a	n/a
Apr	25.6 C (78.1 F)	-15.6 C (3.9 F)	n/a	n/a
May	30.6 C (87.1 F)	-6.1 C (21.0 F)	n/a	n/a
Jun	41.1 C (106.0 F)	-1.1 C (30.0 F)	n/a	n/a
Jul	39.4 C (102.9 F)	6.1 C (43.0 F)	n/a	n/a
Aug	36.1 C (97.0 F)	6.1 C (43.0 F)	n/a	n/a
Sep	35.0 C (95.0 F)	0.0 C (32.0 F)	n/a	n/a
Oct	28.3 C (82.9 F)	-6.7 C (19.9 F)	n/a	n/a
Nov	20.0 C (68.0 F)	-15.0 C (5.0 F)	n/a	n/a
Dec	15.0 C (59.0 F)	-27.8 C (-18.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Plum Island still stand. 1936 holds the most, with 102.

Standing records at Plum Island by the year they were set
Year set	Standing records
1908	25
1909	26
1910	37
1911	26
1912	48
1913	37
1914	54
1915	35
1916	43
1917	49
1918	39
1919	43
1920	38
1921	38
1922	42
1923	42
1924	50
1925	44
1926	30
1927	24
1928	24
1929	35
1930	43
1931	56
1932	43
1933	43
1934	36
1935	52
1936	102
1937	28
1938	26
1939	38
1940	30
1941	44
1942	35
1943	33
1944	26

Wettest Day of Each Month

Aug: 136.4 mm (5.4 in)

The wettest day on record for each calendar month at Plum Island. The most was 136.4 mm (5.4 in) on 25 August 1910.

Record daily precipitation for each month at Plum Island
Month	Record daily precipitation (mm)	Date
Jan	36.3 mm (1.4 in)	2 January 1942
Feb	30.5 mm (1.2 in)	22 February 1922
Mar	63.5 mm (2.5 in)	29 March 1944
Apr	50.8 mm (2.0 in)	9 April 1922
May	59.7 mm (2.4 in)	9 May 1918
Jun	76.2 mm (3.0 in)	17 June 1940
Jul	76.2 mm (3.0 in)	17 July 1942
Aug	136.4 mm (5.4 in)	25 August 1910
Sep	64.5 mm (2.5 in)	21 September 1926
Oct	50.8 mm (2.0 in)	18 October 1923
Nov	43.2 mm (1.7 in)	29 November 1919
Dec	50.0 mm (2.0 in)	2 December 1921

Period of Record Coverage

1908 to 1944

37 years of record at Plum Island, 1908 to 1944. 6 years have data for under 90 percent of days and are left out of rankings: 1908, 1913, 1926, 1942, 1943, 1944.

Days with data per year at Plum Island
Year	Days with data	Share of year	Complete
1908	206	56%	No
1909	336	92%	Yes
1910	357	98%	Yes
1911	348	95%	Yes
1912	362	99%	Yes
1913	301	82%	No
1914	364	100%	Yes
1915	358	98%	Yes
1916	361	99%	Yes
1917	360	99%	Yes
1918	362	99%	Yes
1919	358	98%	Yes
1920	356	97%	Yes
1921	359	98%	Yes
1922	362	99%	Yes
1923	364	100%	Yes
1924	364	99%	Yes
1925	363	99%	Yes
1926	326	89%	No
1927	359	98%	Yes
1928	351	96%	Yes
1929	344	94%	Yes
1930	349	96%	Yes
1931	350	96%	Yes
1932	339	93%	Yes
1933	363	99%	Yes
1934	358	98%	Yes
1935	364	100%	Yes
1936	364	99%	Yes
1937	352	96%	Yes
1938	351	96%	Yes
1939	365	100%	Yes
1940	356	97%	Yes
1941	361	99%	Yes
1942	326	89%	No
1943	278	76%	No
1944	115	31%	No

Latest Records

Latest records at Plum Island
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
31 May 1944	Plum Island, US	daily high min	15.6 C (60.1 F)	2.3 C (4.1 F)	18 years	15 of 100 (Routine)
30 May 1944	Plum Island, US	daily high min	18.3 C (64.9 F)	1.6 C (2.9 F)	12 years	10 of 100 (Routine)
29 May 1944	Plum Island, US	daily high min	17.8 C (64.0 F)	5.0 C (9.0 F)	22 years	24 of 100 (Routine)
28 May 1944	Plum Island, US	monthly high min	21.1 C (70.0 F)	4.4 C (7.9 F)	11 years	29 of 100 (Routine)
27 May 1944	Plum Island, US	daily high min	15.0 C (59.0 F)	2.8 C (5.0 F)	30 years	20 of 100 (Routine)
24 May 1944	Plum Island, US	daily high min	13.3 C (55.9 F)	3.3 C (5.9 F)	3 years	13 of 100 (Routine)
15 May 1944	Plum Island, US	daily high min	10.0 C (50.0 F)	1.1 C (2.0 F)	18 years	11 of 100 (Routine)
14 May 1944	Plum Island, US	daily high min	12.2 C (54.0 F)	3.3 C (5.9 F)	11 years	16 of 100 (Routine)
13 May 1944	Plum Island, US	daily high min	13.3 C (55.9 F)	6.1 C (11.0 F)	14 years	25 of 100 (Routine)
12 May 1944	Plum Island, US	daily high min	12.8 C (55.0 F)	1.7 C (3.1 F)	12 years	11 of 100 (Routine)
8 May 1944	Plum Island, US	daily low max (Tie)	5.6 C (42.1 F)	tie	21 years	2 of 100 (Routine)
6 May 1944	Plum Island, US	daily low max	4.4 C (39.9 F)	1.2 C (2.2 F)	20 years	11 of 100 (Routine)
4 May 1944	Plum Island, US	daily high min (Tie)	10.0 C (50.0 F)	tie	10 years	1 of 100 (Routine)
3 May 1944	Plum Island, US	daily high min	10.0 C (50.0 F)	2.2 C (4.0 F)	16 years	13 of 100 (Routine)
1 May 1944	Plum Island, US	daily high min	7.8 C (46.0 F)	0.6 C (1.1 F)	19 years	9 of 100 (Routine)
29 March 1944	Plum Island, US	monthly rain	63.5 mm (2.5 in)	7.6 mm (0.30 in)	23 years	28 of 100 (Routine)
26 March 1944	Plum Island, US	daily rain	50.8 mm (2.0 in)	35.6 mm (1.4 in)	24 years	50 of 100 (Notable)
15 March 1944	Plum Island, US	daily rain	12.7 mm (0.5 in)	2.5 mm (0.10 in)	25 years	13 of 100 (Routine)
11 March 1944	Plum Island, US	daily high max (Tie)	5.6 C (42.1 F)	tie	23 years	2 of 100 (Routine)
8 March 1944	Plum Island, US	daily rain	12.7 mm (0.5 in)	7.1 mm (0.28 in)	5 years	13 of 100 (Routine)

Climate Trend

26 complete years, 1910 to 1941

One stripe for each of 26 complete years at Plum Island, 1910 to 1941. Blue stripes are years cooler than the station's own mean of 6.2 C (43.2 F); red stripes are warmer. The coolest year was 1936, at 2.8 C (37.0 F), and the warmest was 1931, at 8.8 C (47.8 F). The strongest colour marks a difference of 3.5 C (6.3 F).

Annual mean temperature at Plum Island as warming stripes, 1910 to 1941
Year	Annual mean temperature	Difference from the station mean
1910	6.7 C	+0.46 C
1911	7.0 C	+0.77 C
1912	5.1 C	-1.15 C
1914	6.9 C	+0.70 C
1915	7.3 C	+1.12 C
1916	5.6 C	-0.66 C
1917	3.8 C	-2.47 C
1918	5.5 C	-0.70 C
1919	6.8 C	+0.54 C
1921	8.3 C	+2.11 C
1922	6.5 C	+0.24 C
1923	5.5 C	-0.77 C
1924	6.2 C	-0.07 C
1925	6.2 C	-0.03 C
1927	6.2 C	-0.07 C
1929	5.9 C	-0.30 C
1930	7.0 C	+0.73 C
1931	8.8 C	+2.58 C
1933	6.4 C	+0.16 C
1934	4.8 C	-1.40 C
1935	4.0 C	-2.21 C
1936	2.8 C	-3.43 C
1938	7.7 C	+1.49 C
1939	6.9 C	+0.70 C
1940	6.0 C	-0.20 C
1941	8.1 C	+1.84 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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

1908 to 1944

Yearly extremes at Plum Island: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	41.1 C (106.0 F)	1931	32.2 C (90.0 F)	37
Coldest night (TNn)	-32.2 C (-26.0 F)	1929	-23.9 C (-11.0 F)	37
Wettest day (Rx1day)	136.4 mm (5.4 in)	1910	46.2 mm (1.8 in)	37
Wettest five days (Rx5day)	115.9 mm (4.6 in)	1935	67.1 mm (2.6 in)	37
Longest dry spell (CDD)	62 days	1921	23 days	37

Hottest day (TXx)

The hottest day of the year at Plum Island, 1908 to 1944. The record is 41.1 C (106.0 F) in 1931, marked on the chart; the median year is 32.2 C (90.0 F).

Hottest day (TXx) at Plum Island by year
Year	Hottest day (TXx)
1908	33.3 C (91.9 F)
1909	30.6 C (87.1 F)
1910	37.2 C (99.0 F)
1911	35.6 C (96.1 F)
1912	31.1 C (88.0 F)
1913	32.2 C (90.0 F)
1914	31.7 C (89.1 F)
1915	30.0 C (86.0 F)
1916	37.8 C (100.0 F)
1917	33.9 C (93.0 F)
1918	30.0 C (86.0 F)
1919	31.7 C (89.1 F)
1920	31.7 C (89.1 F)
1921	35.0 C (95.0 F)
1922	33.3 C (91.9 F)
1923	32.2 C (90.0 F)
1924	28.3 C (82.9 F)
1925	30.6 C (87.1 F)
1926	32.8 C (91.0 F)
1927	29.4 C (84.9 F)
1928	31.7 C (89.1 F)
1929	35.0 C (95.0 F)
1930	34.4 C (93.9 F)
1931	41.1 C (106.0 F)
1932	34.4 C (93.9 F)
1933	32.2 C (90.0 F)
1934	32.2 C (90.0 F)
1935	28.9 C (84.0 F)
1936	34.4 C (93.9 F)
1937	29.4 C (84.9 F)
1938	30.6 C (87.1 F)
1939	35.0 C (95.0 F)
1940	29.4 C (84.9 F)
1941	35.6 C (96.1 F)
1942	33.9 C (93.0 F)
1943	30.0 C (86.0 F)
1944	23.3 C (73.9 F)

Coldest night (TNn)

The coldest night of the year at Plum Island, 1908 to 1944. The record is -32.2 C (-26.0 F) in 1929, marked on the chart; the median year is -23.9 C (-11.0 F).

Coldest night (TNn) at Plum Island by year
Year	Coldest night (TNn)
1908	-5.0 C (23.0 F)
1909	-23.9 C (-11.0 F)
1910	-24.4 C (-11.9 F)
1911	-22.2 C (-8.0 F)
1912	-28.3 C (-18.9 F)
1913	-26.7 C (-16.1 F)
1914	-22.2 C (-8.0 F)
1915	-26.1 C (-15.0 F)
1916	-22.2 C (-8.0 F)
1917	-30.6 C (-23.1 F)
1918	-31.7 C (-25.1 F)
1919	-23.3 C (-9.9 F)
1920	-25.6 C (-14.1 F)
1921	-13.9 C (7.0 F)
1922	-23.3 C (-9.9 F)
1923	-28.9 C (-20.0 F)
1924	-26.7 C (-16.1 F)
1925	-25.6 C (-14.1 F)
1926	-22.8 C (-9.0 F)
1927	-23.3 C (-9.9 F)
1928	-22.2 C (-8.0 F)
1929	-32.2 C (-26.0 F)
1930	-22.8 C (-9.0 F)
1931	-17.2 C (1.0 F)
1932	-20.6 C (-5.1 F)
1933	-31.1 C (-24.0 F)
1934	-27.8 C (-18.0 F)
1935	-28.9 C (-20.0 F)
1936	-32.2 C (-26.0 F)
1937	-20.0 C (-4.0 F)
1938	-22.2 C (-8.0 F)
1939	-23.3 C (-9.9 F)
1940	-25.0 C (-13.0 F)
1941	-16.7 C (1.9 F)
1942	-29.4 C (-20.9 F)
1943	-24.4 C (-11.9 F)
1944	-12.2 C (10.0 F)

Wettest day (Rx1day)

The wettest day of the year at Plum Island, 1908 to 1944. The record is 136.4 mm (5.4 in) in 1910, marked on the chart; the median year is 46.2 mm (1.8 in).

Wettest day (Rx1day) at Plum Island by year
Year	Wettest day (Rx1day)
1908	26.7 mm (1.1 in)
1909	30.5 mm (1.2 in)
1910	136.4 mm (5.4 in)
1911	48.3 mm (1.9 in)
1912	34.0 mm (1.3 in)
1913	33.5 mm (1.3 in)
1914	51.3 mm (2.0 in)
1915	31.5 mm (1.2 in)
1916	66.0 mm (2.6 in)
1917	50.8 mm (2.0 in)
1918	59.7 mm (2.4 in)
1919	43.2 mm (1.7 in)
1920	25.4 mm (1.0 in)
1921	56.6 mm (2.2 in)
1922	50.8 mm (2.0 in)
1923	50.8 mm (2.0 in)
1924	46.2 mm (1.8 in)
1925	50.8 mm (2.0 in)
1926	64.5 mm (2.5 in)
1927	45.7 mm (1.8 in)
1928	38.1 mm (1.5 in)
1929	30.5 mm (1.2 in)
1930	22.9 mm (0.9 in)
1931	67.3 mm (2.6 in)
1932	31.8 mm (1.3 in)
1933	22.9 mm (0.9 in)
1934	43.2 mm (1.7 in)
1935	56.9 mm (2.2 in)
1936	20.3 mm (0.8 in)
1937	17.8 mm (0.7 in)
1938	25.4 mm (1.0 in)
1939	73.7 mm (2.9 in)
1940	76.2 mm (3.0 in)
1941	50.8 mm (2.0 in)
1942	76.2 mm (3.0 in)
1943	45.7 mm (1.8 in)
1944	63.5 mm (2.5 in)

Wettest five days (Rx5day)

The wettest five days of the year at Plum Island, 1908 to 1944. The record is 115.9 mm (4.6 in) in 1935, marked on the chart; the median year is 67.1 mm (2.6 in).

Wettest five days (Rx5day) at Plum Island by year
Year	Wettest five days (Rx5day)
1908	38.6 mm (1.5 in)
1909	45.4 mm (1.8 in)
1910	69.6 mm (2.7 in)
1911	71.2 mm (2.8 in)
1912	72.9 mm (2.9 in)
1913	55.6 mm (2.2 in)
1914	50.8 mm (2.0 in)
1915	60.2 mm (2.4 in)
1916	66.0 mm (2.6 in)
1917	76.2 mm (3.0 in)
1918	105.4 mm (4.1 in)
1919	63.5 mm (2.5 in)
1920	60.9 mm (2.4 in)
1921	78.8 mm (3.1 in)
1922	58.9 mm (2.3 in)
1923	92.7 mm (3.6 in)
1924	67.1 mm (2.6 in)
1925	53.4 mm (2.1 in)
1926	96.5 mm (3.8 in)
1927	81.7 mm (3.2 in)
1928	83.6 mm (3.3 in)
1929	62.3 mm (2.5 in)
1930	42.0 mm (1.7 in)
1931	77.5 mm (3.1 in)
1932	48.3 mm (1.9 in)
1933	59.1 mm (2.3 in)
1934	88.9 mm (3.5 in)
1935	115.9 mm (4.6 in)
1936	35.5 mm (1.4 in)
1937	25.9 mm (1.0 in)
1938	51.6 mm (2.0 in)
1939	99.5 mm (3.9 in)
1940	103.1 mm (4.1 in)
1941	93.9 mm (3.7 in)
1942	94.8 mm (3.7 in)
1943	72.9 mm (2.9 in)
1944	15.4 mm (0.6 in)

Longest dry spell (CDD)

The longest dry spell of the year at Plum Island, 1908 to 1944. The record is 62 days in 1921, marked on the chart; the median year is 23 days.

Longest dry spell (CDD) at Plum Island by year
Year	Longest dry spell (CDD)
1908	28 days
1909	17 days
1910	30 days
1911	20 days
1912	19 days
1913	29 days
1914	43 days
1915	21 days
1916	29 days
1917	25 days
1918	23 days
1919	27 days
1920	19 days
1921	62 days
1922	27 days
1923	26 days
1924	23 days
1925	26 days
1926	17 days
1927	14 days
1928	22 days
1929	25 days
1930	19 days
1931	19 days
1932	23 days
1933	30 days
1934	35 days
1935	19 days
1936	21 days
1937	23 days
1938	22 days
1939	17 days
1940	12 days
1941	23 days
1942	29 days
1943	23 days
1944	18 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

26 years with a frost

Across 26 years with a frost, the median last spring frost at Plum Island falls on 14 May and the median first autumn frost on 22 October, which leaves a median of 166 days between them.

Fitted over all years, the growing season changes by +1.4 days per decade at this station.

Frost dates and growing season at Plum Island
Measure	Median, all years	Earliest period	Recent period (1910 to 1941)	Recent against earliest	Fitted trend
Last spring frost	14 May	n/a	14 May	n/a	+1.0 days per decade
First autumn frost	22 October	n/a	22 October	n/a	+2.4 days per decade
Growing days	166 days	n/a	166 days	n/a	+1.4 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 Plum Island standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Plum Island 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).