Grass River Threshold Days by Year (CA005041140)

16 fixed thresholds counted per year at Grass River (CA005041140): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Grass River Thresholds

Grass River: days with a maximum temperature at or above 30 C (86 F) in 25 years, most in 1961 with 46.
Grass River: days with a maximum temperature at or above 90 F (32.2 C) in 25 years, most in 1961 with 24.
Grass River: days with a maximum temperature at or below 0 C (32 F) in 25 years, most in 1972 with 141.
Grass River: nights with a minimum temperature at or below 0 C (32 F) in 25 years, most in 1959 with 217.
16 fixed thresholds have at least one qualifying day at Grass River.

Days at or above 30 C (86 F)

25 years with a qualifying day

Days per year at Grass River with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 46 in 1961.

Days at or above 30 C (86 F) per year at Grass River
Year	Days	Decade average
1958	14	13
1959	12	13
1960	16	15.6
1961	46	15.6
1962	4	15.6
1963	13	15.6
1964	14	15.6
1965	6	15.6
1966	20	15.6
1967	22	15.6
1968	4	15.6
1969	11	15.6
1970	21	15.7
1971	7	15.7
1972	13	15.7
1973	16	15.7
1974	16	15.7
1975	14	15.7
1976	24	15.7
1977	11	15.7
1978	21	15.7
1979	14	15.7
1980	31	29
1981	19	29
1983	37	29

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

First to last qualifying date each year at Grass River
Year	First date	Last date
1958	1958-05-12	1958-08-18
1959	1959-05-17	1959-08-18
1960	1960-05-12	1960-08-20
1961	1961-05-21	1961-10-16
1962	1962-06-09	1962-08-21
1963	1963-05-30	1963-09-30
1964	1964-05-17	1964-09-17
1965	1965-08-08	1965-08-23
1966	1966-05-21	1966-09-07
1967	1967-06-03	1967-09-06
1968	1968-06-03	1968-07-14
1969	1969-07-11	1969-08-26
1970	1970-05-17	1970-09-05
1971	1971-05-28	1971-08-27
1972	1972-05-16	1972-08-30
1973	1973-05-17	1973-08-30
1974	1974-06-19	1974-08-07
1975	1975-06-20	1975-07-30
1976	1976-06-02	1976-09-17
1977	1977-04-26	1977-07-22
1978	1978-05-16	1978-09-10
1979	1979-06-12	1979-09-16
1980	1980-04-18	1980-09-07
1981	1981-05-20	1981-08-30
1983	1983-06-10	1983-09-27

Every Fixed Threshold

Fixed thresholds at Grass River
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	25	46	1961	37
35 C (95 F): Days	15	8	1961	6
90 F (32.2 C): Days	25	24	1961	14
100 F (37.8 C): Days	5	1	1961	1
0 C (32 F): Ice days (max	25	141	1972	115
0 C (32 F): Frost days (min	25	217	1959	217
-10 C (14 F): Days with min	25	131	1976	111
-20 C (-4 F): Days with min	25	88	1970	51
-30 C (-22 F): Days with min	25	33	1978	16
-40 C (-40 F): Days with min	8	7	1966	3
20 C (68 F): Tropical nights (min	8	3	1960	1
10 mm (0.39 in): Days with 10 mm or more rain	25	24	1975	7
25 mm (0.98 in): Days with 25 mm or more rain	23	8	1975	2
50 mm (1.97 in): Days with 50 mm or more rain	6	2	1975	1
10 cm (3.9 in): Days with 10 cm or more snowfall	21	8	1970	2
25 cm (9.8 in): Days with 25 cm or more snowfall	4	2	1959	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1958.

Download the Data

Data for Grass River 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 2026-10-17. Last revised 17 October 2026 (2026-10-17).

Grass River Threshold Days by Year (CA005041140)

Key Facts for Grass River Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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