Grand Valley Threshold Days by Year

17 fixed thresholds counted per year at Grand Valley (USC00053508): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Grand Valley Thresholds

Grand Valley: days with 10 mm (0.39 in) or more of precipitation in 24 years, most in 1969 with 17.
Grand Valley: days with a maximum temperature at or above 30 C (86 F) in 22 years, most in 1974 with 103.
Grand Valley: days with a maximum temperature at or above 35 C (95 F) in 22 years, most in 1980 with 52.
Grand Valley: days with a maximum temperature at or above 90 F (32.2 C) in 22 years, most in 1977 with 86.
17 fixed thresholds have at least one qualifying day at Grand Valley.

Days at or above 30 C (86 F)

22 years with a qualifying day

Days per year at Grand Valley with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 103 in 1974.

Days at or above 30 C (86 F) per year at Grand Valley
Year	Days	Decade average
1905	73	64.2
1906	66	64.2
1907	55	64.2
1908	68	64.2
1909	59	64.2
1910	85	71
1912	57	71
1966	95	82.8
1967	81	82.8
1968	73	82.8
1969	82	82.8
1970	79	91.3
1971	88	91.3
1972	96	91.3
1973	80	91.3
1974	103	91.3
1975	81	91.3
1976	88	91.3
1977	103	91.3
1978	97	91.3
1979	98	91.3
1980	98	98

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

First to last qualifying date each year at Grand Valley
Year	First date	Last date
1905	1905-06-03	1905-09-23
1906	1906-06-09	1906-09-10
1907	1907-05-22	1907-09-17
1908	1908-06-20	1908-09-14
1909	1909-05-19	1909-09-27
1910	1910-05-10	1910-10-10
1912	1912-05-29	1912-08-28
1966	1966-05-04	1966-09-25
1967	1967-05-21	1967-09-25
1968	1968-05-29	1968-09-12
1969	1969-05-25	1969-09-07
1970	1970-05-17	1970-09-11
1971	1971-05-26	1971-09-15
1972	1972-05-15	1972-09-18
1973	1973-05-18	1973-09-08
1974	1974-05-08	1974-09-24
1975	1975-05-14	1975-09-07
1976	1976-05-14	1976-09-06
1977	1977-05-09	1977-09-20
1978	1978-05-14	1978-09-27
1979	1979-05-20	1979-10-02
1980	1980-05-21	1980-10-09

Every Fixed Threshold

Fixed thresholds at Grand Valley
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	22	103	1974	98
35 C (95 F): Days	22	52	1980	52
40 C (104 F): Days	4	2	1976	2
90 F (32.2 C): Days	22	86	1977	73
100 F (37.8 C): Days	17	9	1971	8
0 C (32 F): Ice days (max	22	32	1905	4
0 C (32 F): Frost days (min	22	200	1975	172
-10 C (14 F): Days with min	22	77	1975	12
-20 C (-4 F): Days with min	20	16	1974	16
-30 C (-22 F): Days with min	1	2	1979	2
20 C (68 F): Tropical nights (min	5	3	1912	1
25 C (77 F): Days with min	1	1	1912	1
10 mm (0.39 in): Days with 10 mm or more rain	24	17	1969	14
25 mm (0.98 in): Days with 25 mm or more rain	9	3	1969	1
50 mm (1.97 in): Days with 50 mm or more rain	2	1	1966	1
10 cm (3.9 in): Days with 10 cm or more snowfall	15	6	1967	3
25 cm (9.8 in): Days with 25 cm or more snowfall	1	1	1980	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1905.

Download the Data

Data for Grand Valley 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).

Grand Valley Threshold Days by Year

Key Facts for Grand Valley Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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