Williams Bay Weather Records (USC00479226)

Record envelope, standing records and threshold days for Williams Bay (USC00479226), Wisconsin, United States, with 34 years of record.

Key Facts for Williams Bay

Williams Bay (USC00479226) is a weather station in Wisconsin, United States at 42.58 latitude and -88.53 longitude, 271 m (889 ft) above sea level.
The station reports from 1925 to 1958, 34 years of record.
1,464 records set at Williams Bay still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Williams Bay set a daily record snowfall of 10.2 cm (4.0 in) on 22 January 1958.

About the Station

Location: Wisconsin, United States, 42.58 latitude, -88.53 longitude.
Elevation: 271 m (889 ft).
Period of record: 1925 to 1958, 34 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 Williams Bay. 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 Williams Bay, 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)	-32.2 C (-26.0 F)	n/a	n/a
Feb	16.7 C (62.1 F)	-33.9 C (-29.0 F)	n/a	n/a
Mar	24.4 C (75.9 F)	-22.8 C (-9.0 F)	n/a	n/a
Apr	31.7 C (89.1 F)	-11.1 C (12.0 F)	n/a	n/a
May	40.0 C (104.0 F)	-3.3 C (26.1 F)	n/a	n/a
Jun	40.6 C (105.1 F)	1.7 C (35.1 F)	n/a	n/a
Jul	43.3 C (109.9 F)	6.7 C (44.1 F)	n/a	n/a
Aug	37.8 C (100.0 F)	5.6 C (42.1 F)	n/a	n/a
Sep	36.7 C (98.1 F)	-4.4 C (24.1 F)	n/a	n/a
Oct	31.1 C (88.0 F)	-15.0 C (5.0 F)	n/a	n/a
Nov	25.0 C (77.0 F)	-23.3 C (-9.9 F)	n/a	n/a
Dec	16.1 C (61.0 F)	-29.4 C (-20.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Williams Bay still stand. 1936 holds the most, with 88.

Standing records at Williams Bay by the year they were set
Year set	Standing records
1925	67
1926	46
1927	62
1928	44
1929	52
1930	60
1931	54
1932	51
1933	48
1934	67
1935	32
1936	88
1937	29
1938	31
1939	34
1940	46
1941	47
1942	51
1943	34
1944	39
1945	57
1946	44
1947	53
1948	36
1949	31
1950	44
1951	54
1952	24
1953	35
1954	26
1955	25
1956	32
1957	20
1958	1

Wettest Day of Each Month

Jul: 142.5 mm (5.6 in)

The wettest day on record for each calendar month at Williams Bay. The most was 142.5 mm (5.6 in) on 1 July 1938.

Record daily precipitation for each month at Williams Bay
Month	Record daily precipitation (mm)	Date
Jan	62.0 mm (2.4 in)	24 January 1938
Feb	35.6 mm (1.4 in)	23 February 1925
Mar	50.3 mm (2.0 in)	19 March 1948
Apr	67.6 mm (2.7 in)	23 April 1950
May	60.2 mm (2.4 in)	10 May 1948
Jun	69.9 mm (2.8 in)	28 June 1945
Jul	142.5 mm (5.6 in)	1 July 1938
Aug	79.5 mm (3.1 in)	26 August 1943
Sep	74.9 mm (2.9 in)	21 September 1947
Oct	56.6 mm (2.2 in)	7 October 1930
Nov	70.6 mm (2.8 in)	17 November 1928
Dec	43.2 mm (1.7 in)	27 December 1942

Period of Record Coverage

1925 to 1958

34 years of record at Williams Bay, 1925 to 1958. 1 years have data for under 90 percent of days and are left out of rankings: 1958.

Days with data per year at Williams Bay
Year	Days with data	Share of year	Complete
1925	363	99%	Yes
1926	365	100%	Yes
1927	365	100%	Yes
1928	366	100%	Yes
1929	364	100%	Yes
1930	352	96%	Yes
1931	365	100%	Yes
1932	365	100%	Yes
1933	365	100%	Yes
1934	360	99%	Yes
1935	363	99%	Yes
1936	365	100%	Yes
1937	351	96%	Yes
1938	365	100%	Yes
1939	363	99%	Yes
1940	366	100%	Yes
1941	364	100%	Yes
1942	365	100%	Yes
1943	363	99%	Yes
1944	364	99%	Yes
1945	359	98%	Yes
1946	365	100%	Yes
1947	359	98%	Yes
1948	365	100%	Yes
1949	334	92%	Yes
1950	339	93%	Yes
1951	363	99%	Yes
1952	365	100%	Yes
1953	365	100%	Yes
1954	364	100%	Yes
1955	365	100%	Yes
1956	363	99%	Yes
1957	351	96%	Yes
1958	31	8%	No

Latest Records

Latest records at Williams Bay
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
22 January 1958	Williams Bay, US	daily snowfall	10.2 cm (4.0 in)	4.4 cm (1.7 in)	6 years	13 of 100 (Routine)
21 January 1958	Williams Bay, US	daily snowfall	7.6 cm (3.0 in)	3.0 cm (1.2 in)	15 years	13 of 100 (Routine)
20 January 1958	Williams Bay, US	daily high min (Tie)	-3.3 C (26.1 F)	tie	26 years	2 of 100 (Routine)
3 January 1958	Williams Bay, US	daily low min	-22.8 C (-9.0 F)	1.7 C (3.1 F)	16 years	9 of 100 (Routine)
31 December 1957	Williams Bay, US	daily snowfall	8.9 cm (3.5 in)	3.8 cm (1.5 in)	26 years	21 of 100 (Routine)
31 December 1957	Williams Bay, US	daily rain	10.2 mm (0.4 in)	3.8 mm (0.15 in)	26 years	16 of 100 (Routine)
28 December 1957	Williams Bay, US	daily snowfall	3.8 cm (1.5 in)	0.5 cm (0.2 in)	3 years	4 of 100 (Routine)
25 December 1957	Williams Bay, US	daily rain	12.7 mm (0.5 in)	2.8 mm (0.11 in)	6 years	8 of 100 (Routine)
22 December 1957	Williams Bay, US	daily high max (Tie)	11.7 C (53.1 F)	tie	26 years	2 of 100 (Routine)
20 December 1957	Williams Bay, US	daily high max	5.0 C (41.0 F)	0.6 C (1.1 F)	31 years	13 of 100 (Routine)
20 December 1957	Williams Bay, US	daily rain	8.9 mm (0.35 in)	3.1 mm (0.12 in)	6 years	9 of 100 (Routine)
20 December 1957	Williams Bay, US	daily high min (Tie)	0.0 C (32.0 F)	tie	26 years	2 of 100 (Routine)
19 December 1957	Williams Bay, US	daily high max	10.6 C (51.1 F)	2.3 C (4.1 F)	16 years	10 of 100 (Routine)
19 December 1957	Williams Bay, US	daily high min (Tie)	1.7 C (35.1 F)	tie	16 years	1 of 100 (Routine)
18 December 1957	Williams Bay, US	daily rain	13.7 mm (0.5 in)	8.4 mm (0.33 in)	28 years	20 of 100 (Routine)
13 December 1957	Williams Bay, US	daily high max	7.8 C (46.0 F)	0.6 C (1.1 F)	30 years	13 of 100 (Routine)
11 December 1957	Williams Bay, US	daily low min (Tie)	-18.3 C (-0.9 F)	tie	20 years	2 of 100 (Routine)
6 December 1957	Williams Bay, US	daily high min	3.3 C (37.9 F)	0.5 C (0.9 F)	6 years	4 of 100 (Routine)
27 November 1957	Williams Bay, US	daily high max	14.4 C (57.9 F)	1.6 C (2.9 F)	30 years	14 of 100 (Routine)
10 November 1957	Williams Bay, US	daily low min	-11.1 C (12.0 F)	1.1 C (2.0 F)	31 years	13 of 100 (Routine)

Climate Trend

28 complete years, 1925 to 1956

One stripe for each of 28 complete years at Williams Bay, 1925 to 1956. Blue stripes are years cooler than the station's own mean of 8.6 C (47.6 F); red stripes are warmer. The coolest year was 1951, at 7.1 C (44.7 F), and the warmest was 1931, at 10.3 C (50.6 F). The strongest colour marks a difference of 1.7 C (3.1 F).

Annual mean temperature at Williams Bay as warming stripes, 1925 to 1956
Year	Annual mean temperature	Difference from the station mean
1925	8.1 C	-0.60 C
1926	7.2 C	-1.48 C
1927	8.6 C	-0.04 C
1928	8.5 C	-0.14 C
1929	7.2 C	-1.50 C
1931	10.3 C	+1.68 C
1932	8.4 C	-0.28 C
1933	9.2 C	+0.57 C
1934	9.6 C	+0.92 C
1935	8.2 C	-0.47 C
1936	8.1 C	-0.60 C
1938	9.4 C	+0.73 C
1939	9.1 C	+0.47 C
1940	7.3 C	-1.33 C
1941	9.6 C	+0.92 C
1942	8.4 C	-0.25 C
1943	8.2 C	-0.46 C
1944	9.1 C	+0.49 C
1945	8.0 C	-0.67 C
1946	9.6 C	+0.95 C
1947	8.4 C	-0.27 C
1948	8.8 C	+0.16 C
1951	7.1 C	-1.60 C
1952	9.2 C	+0.52 C
1953	9.9 C	+1.27 C
1954	9.2 C	+0.57 C
1955	9.0 C	+0.34 C
1956	8.7 C	+0.06 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

1925 to 1958

Yearly extremes at Williams Bay: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	43.3 C (109.9 F)	1936	35.9 C (96.5 F)	34
Coldest night (TNn)	-33.9 C (-29.0 F)	1933	-26.1 C (-15.0 F)	34
Wettest day (Rx1day)	142.5 mm (5.6 in)	1938	55.6 mm (2.2 in)	34
Wettest five days (Rx5day)	149.9 mm (5.9 in)	1950	90.5 mm (3.6 in)	34
Longest dry spell (CDD)	47 days	1952	22 days	34

Hottest day (TXx)

The hottest day of the year at Williams Bay, 1925 to 1958. The record is 43.3 C (109.9 F) in 1936, marked on the chart; the median year is 35.9 C (96.5 F).

Hottest day (TXx) at Williams Bay by year
Year	Hottest day (TXx)
1925	36.1 C (97.0 F)
1926	34.4 C (93.9 F)
1927	36.7 C (98.1 F)
1928	32.8 C (91.0 F)
1929	33.9 C (93.0 F)
1930	37.8 C (100.0 F)
1931	37.8 C (100.0 F)
1932	36.1 C (97.0 F)
1933	37.2 C (99.0 F)
1934	42.2 C (108.0 F)
1935	35.0 C (95.0 F)
1936	43.3 C (109.9 F)
1937	35.6 C (96.1 F)
1938	35.0 C (95.0 F)
1939	36.7 C (98.1 F)
1940	37.8 C (100.0 F)
1941	37.8 C (100.0 F)
1942	34.4 C (93.9 F)
1943	33.9 C (93.0 F)
1944	36.1 C (97.0 F)
1945	34.4 C (93.9 F)
1946	36.1 C (97.0 F)
1947	37.8 C (100.0 F)
1948	36.1 C (97.0 F)
1949	34.4 C (93.9 F)
1950	31.1 C (88.0 F)
1951	30.6 C (87.1 F)
1952	33.9 C (93.0 F)
1953	36.7 C (98.1 F)
1954	33.3 C (91.9 F)
1955	37.2 C (99.0 F)
1956	33.3 C (91.9 F)
1957	31.7 C (89.1 F)
1958	4.4 C (39.9 F)

Coldest night (TNn)

The coldest night of the year at Williams Bay, 1925 to 1958. The record is -33.9 C (-29.0 F) in 1933, marked on the chart; the median year is -26.1 C (-15.0 F).

Coldest night (TNn) at Williams Bay by year
Year	Coldest night (TNn)
1925	-28.3 C (-18.9 F)
1926	-26.7 C (-16.1 F)
1927	-28.3 C (-18.9 F)
1928	-23.3 C (-9.9 F)
1929	-28.9 C (-20.0 F)
1930	-31.7 C (-25.1 F)
1931	-25.0 C (-13.0 F)
1932	-26.7 C (-16.1 F)
1933	-33.9 C (-29.0 F)
1934	-24.4 C (-11.9 F)
1935	-27.2 C (-17.0 F)
1936	-32.2 C (-26.0 F)
1937	-20.6 C (-5.1 F)
1938	-22.2 C (-8.0 F)
1939	-19.4 C (-2.9 F)
1940	-31.7 C (-25.1 F)
1941	-24.4 C (-11.9 F)
1942	-31.1 C (-24.0 F)
1943	-27.2 C (-17.0 F)
1944	-25.0 C (-13.0 F)
1945	-26.7 C (-16.1 F)
1946	-23.9 C (-11.0 F)
1947	-23.9 C (-11.0 F)
1948	-26.1 C (-15.0 F)
1949	-24.4 C (-11.9 F)
1950	-26.7 C (-16.1 F)
1951	-32.2 C (-26.0 F)
1952	-25.0 C (-13.0 F)
1953	-21.7 C (-7.1 F)
1954	-26.1 C (-15.0 F)
1955	-26.7 C (-16.1 F)
1956	-21.7 C (-7.1 F)
1957	-25.0 C (-13.0 F)
1958	-23.9 C (-11.0 F)

Wettest day (Rx1day)

The wettest day of the year at Williams Bay, 1925 to 1958. The record is 142.5 mm (5.6 in) in 1938, marked on the chart; the median year is 55.6 mm (2.2 in).

Wettest day (Rx1day) at Williams Bay by year
Year	Wettest day (Rx1day)
1925	61.7 mm (2.4 in)
1926	51.6 mm (2.0 in)
1927	43.7 mm (1.7 in)
1928	70.6 mm (2.8 in)
1929	103.1 mm (4.1 in)
1930	56.6 mm (2.2 in)
1931	47.0 mm (1.9 in)
1932	55.6 mm (2.2 in)
1933	43.2 mm (1.7 in)
1934	55.6 mm (2.2 in)
1935	59.2 mm (2.3 in)
1936	49.3 mm (1.9 in)
1937	43.2 mm (1.7 in)
1938	142.5 mm (5.6 in)
1939	62.7 mm (2.5 in)
1940	72.1 mm (2.8 in)
1941	68.8 mm (2.7 in)
1942	43.7 mm (1.7 in)
1943	79.5 mm (3.1 in)
1944	37.1 mm (1.5 in)
1945	69.9 mm (2.8 in)
1946	39.6 mm (1.6 in)
1947	74.9 mm (2.9 in)
1948	60.2 mm (2.4 in)
1949	30.5 mm (1.2 in)
1950	81.0 mm (3.2 in)
1951	43.2 mm (1.7 in)
1952	85.6 mm (3.4 in)
1953	46.2 mm (1.8 in)
1954	67.3 mm (2.6 in)
1955	53.3 mm (2.1 in)
1956	39.6 mm (1.6 in)
1957	46.0 mm (1.8 in)
1958	7.6 mm (0.30 in)

Wettest five days (Rx5day)

The wettest five days of the year at Williams Bay, 1925 to 1958. The record is 149.9 mm (5.9 in) in 1950, marked on the chart; the median year is 90.5 mm (3.6 in).

Wettest five days (Rx5day) at Williams Bay by year
Year	Wettest five days (Rx5day)
1925	77.8 mm (3.1 in)
1926	101.3 mm (4.0 in)
1927	78.7 mm (3.1 in)
1928	107.9 mm (4.2 in)
1929	147.6 mm (5.8 in)
1930	60.9 mm (2.4 in)
1931	67.9 mm (2.7 in)
1932	76.9 mm (3.0 in)
1933	84.8 mm (3.3 in)
1934	144.4 mm (5.7 in)
1935	83.1 mm (3.3 in)
1936	92.5 mm (3.6 in)
1937	94.0 mm (3.7 in)
1938	130.3 mm (5.1 in)
1939	68.8 mm (2.7 in)
1940	131.6 mm (5.2 in)
1941	132.3 mm (5.2 in)
1942	63.1 mm (2.5 in)
1943	90.6 mm (3.6 in)
1944	59.0 mm (2.3 in)
1945	92.0 mm (3.6 in)
1946	74.4 mm (2.9 in)
1947	74.9 mm (2.9 in)
1948	109.2 mm (4.3 in)
1949	42.1 mm (1.7 in)
1950	149.9 mm (5.9 in)
1951	70.6 mm (2.8 in)
1952	99.8 mm (3.9 in)
1953	90.4 mm (3.6 in)
1954	113.7 mm (4.5 in)
1955	93.9 mm (3.7 in)
1956	91.7 mm (3.6 in)
1957	56.9 mm (2.2 in)
1958	19.1 mm (0.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Williams Bay, 1925 to 1958. The record is 47 days in 1952, marked on the chart; the median year is 22 days.

Longest dry spell (CDD) at Williams Bay by year
Year	Longest dry spell (CDD)
1925	31 days
1926	17 days
1927	19 days
1928	15 days
1929	13 days
1930	21 days
1931	17 days
1932	23 days
1933	37 days
1934	24 days
1935	14 days
1936	26 days
1937	22 days
1938	17 days
1939	29 days
1940	14 days
1941	14 days
1942	28 days
1943	25 days
1944	27 days
1945	20 days
1946	12 days
1947	26 days
1948	20 days
1949	25 days
1950	30 days
1951	13 days
1952	47 days
1953	26 days
1954	25 days
1955	21 days
1956	12 days
1957	28 days
1958	19 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

28 years with a frost

Across 28 years with a frost, the median last spring frost at Williams Bay falls on 2 May and the median first autumn frost on 7 October, which leaves a median of 162 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 Williams Bay
Measure	Median, all years	Earliest period	Recent period (1925 to 1956)	Recent against earliest	Fitted trend
Last spring frost	2 May	n/a	2 May	n/a	-4.7 days per decade
First autumn frost	7 October	n/a	7 October	n/a	-0.3 days per decade
Growing days	162 days	n/a	162 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.

Rainfall Return Levels

31 years, 1925 to 1957

A day with at least 54.6 mm (2.1 in) of rain is expected about once in 2 years. A day with at least 147.0 mm (5.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Williams Bay: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	54.6 mm (2.1 in)
5 years	73.2 mm (2.9 in)
10 years	87.7 mm (3.5 in)
25 years	108.8 mm (4.3 in)
50 years	126.8 mm (5.0 in)	Longer than the 31 years of record
100 years	147.0 mm (5.8 in)	Longer than the 31 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, 31 years of values from 1925 to 1957.

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: 142.5 mm (5.6 in) in 1938; 103.1 mm (4.1 in) in 1929; 85.6 mm (3.4 in) in 1952.

Download the Data

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