Waterloo Threshold Days by Year (USC00138704)

18 fixed thresholds counted per year at Waterloo (USC00138704): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Waterloo Thresholds

Waterloo: days with a maximum temperature at or above 30 C (86 F) in 55 years, most in 1921 with 78.
Waterloo: days with a maximum temperature at or above 90 F (32.2 C) in 55 years, most in 1936 with 60.
Waterloo: days with a maximum temperature at or below 0 C (32 F) in 55 years, most in 1937 with 81.
Waterloo: nights with a minimum temperature at or below 0 C (32 F) in 55 years, most in 1917 with 173.
18 fixed thresholds have at least one qualifying day at Waterloo.

Days at or above 30 C (86 F)

55 years with a qualifying day

Days per year at Waterloo with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 78 in 1921.

Days at or above 30 C (86 F) per year at Waterloo
Year	Days	Decade average
1895	67	52
1896	45	52
1897	56	52
1898	47	52
1899	45	52
1900	57	41
1901	74	41
1902	22	41
1903	20	41
1904	25	41
1905	33	41
1906	41	41
1907	38	41
1908	52	41
1909	48	41
1910	62	47.6
1911	51	47.6
1912	34	47.6
1913	57	47.6
1914	67	47.6
1915	23	47.6
1916	58	47.6
1917	36	47.6
1918	43	47.6
1919	45	47.6
1920	46	51
1921	78	51
1922	62	51
1923	53	51
1924	26	51
1925	65	51
1926	50	51
1927	50	51
1928	34	51
1929	46	51
1930	59	64.2
1931	73	64.2
1932	49	64.2
1933	73	64.2
1934	70	64.2
1935	54	64.2
1936	74	64.2
1937	65	64.2
1938	56	64.2
1939	69	64.2
1940	48	40.2
1941	53	40.2
1942	34	40.2
1943	43	40.2
1944	36	40.2
1945	27	40.2
1946	23	40.2
1947	50	40.2
1948	43	40.2
1949	45	40.2

For each year, a bar from the first to the last day at Waterloo meeting 30 C (86 F).

First to last qualifying date each year at Waterloo
Year	First date	Last date
1895	1895-04-30	1895-09-22
1896	1896-05-06	1896-08-14
1897	1897-05-06	1897-10-14
1898	1898-04-16	1898-09-29
1899	1899-06-04	1899-10-23
1900	1900-05-11	1900-10-05
1901	1901-04-29	1901-09-27
1902	1902-04-21	1902-08-18
1903	1903-07-01	1903-08-25
1904	1904-05-23	1904-09-29
1905	1905-06-05	1905-09-28
1906	1906-05-24	1906-09-17
1907	1907-03-27	1907-09-20
1908	1908-05-18	1908-09-26
1909	1909-05-06	1909-09-21
1910	1910-03-24	1910-10-17
1911	1911-05-10	1911-09-15
1912	1912-05-24	1912-09-10
1913	1913-05-01	1913-09-08
1914	1914-05-11	1914-09-20
1915	1915-05-14	1915-09-14
1916	1916-04-13	1916-10-08
1917	1917-05-18	1917-09-17
1918	1918-05-04	1918-10-12
1919	1919-05-28	1919-10-01
1920	1920-05-22	1920-10-11
1921	1921-05-20	1921-09-16
1922	1922-05-10	1922-10-05
1923	1923-05-29	1923-09-05
1924	1924-05-05	1924-08-31
1925	1925-04-12	1925-09-19
1926	1926-04-30	1926-09-21
1927	1927-05-21	1927-10-26
1928	1928-05-09	1928-10-11
1929	1929-05-28	1929-09-27
1930	1930-04-10	1930-10-12
1931	1931-04-08	1931-10-04
1932	1932-05-13	1932-08-30
1933	1933-05-25	1933-09-25
1934	1934-05-04	1934-08-18
1935	1935-06-12	1935-09-24
1936	1936-05-06	1936-09-22
1937	1937-05-29	1937-09-23
1938	1938-06-14	1938-10-16
1939	1939-04-24	1939-09-28
1940	1940-05-12	1940-09-21
1941	1941-05-15	1941-09-21
1942	1942-04-29	1942-09-16
1943	1943-05-28	1943-08-31
1944	1944-05-14	1944-09-03
1945	1945-06-23	1945-09-07
1946	1946-06-10	1946-08-17
1947	1947-06-09	1947-10-21
1948	1948-04-18	1948-09-19
1949	1949-04-25	1949-08-26

Every Fixed Threshold

Fixed thresholds at Waterloo
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	55	78	1921	45
35 C (95 F): Days	50	36	1931	3
40 C (104 F): Days	10	13	1936	1
90 F (32.2 C): Days	55	60	1936	21
100 F (37.8 C): Days	25	20	1936	3
110 F (43.3 C): Days	1	4	1936	4
0 C (32 F): Ice days (max	55	81	1937	58
0 C (32 F): Frost days (min	55	173	1917	161
-10 C (14 F): Days with min	55	81	1917	57
-20 C (-4 F): Days with min	55	41	1917	14
-30 C (-22 F): Days with min	23	6	1936	1
20 C (68 F): Tropical nights (min	55	36	1934	26
25 C (77 F): Days with min	9	3	1917	1
10 mm (0.39 in): Days with 10 mm or more rain	2	21	1948	19
25 mm (0.98 in): Days with 25 mm or more rain	2	7	1948	3
50 mm (1.97 in): Days with 50 mm or more rain	1	2	1948	2
10 cm (3.9 in): Days with 10 cm or more snowfall	30	3	1949	3
25 cm (9.8 in): Days with 25 cm or more snowfall	2	1	1906	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1895.

Download the Data

Data for Waterloo 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). Threshold counts are computed by this site.

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

Waterloo Threshold Days by Year (USC00138704)

Key Facts for Waterloo Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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