Rock Springs Threshold Days by Year (USC00487840)

13 fixed thresholds counted per year at Rock Springs (USC00487840): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Rock Springs Thresholds

Rock Springs: days with a maximum temperature at or above 30 C (86 F) in 39 years, most in 1940 with 63.
Rock Springs: days with a maximum temperature at or above 90 F (32.2 C) in 39 years, most in 1940 with 35.
Rock Springs: days with a maximum temperature at or below 0 C (32 F) in 39 years, most in 1964 with 69.
Rock Springs: nights with a minimum temperature at or below 0 C (32 F) in 39 years, most in 1975 with 223.
13 fixed thresholds have at least one qualifying day at Rock Springs.

Days at or above 30 C (86 F)

39 years with a qualifying day

Days per year at Rock Springs with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 63 in 1940.

Days at or above 30 C (86 F) per year at Rock Springs
Year	Days	Decade average
1933	46	37.4
1934	36	37.4
1935	40	37.4
1936	50	37.4
1937	37	37.4
1938	21	37.4
1939	32	37.4
1940	63	42.3
1941	28	42.3
1949	36	42.3
1950	29	41.5
1951	25	41.5
1952	41	41.5
1953	50	41.5
1954	54	41.5
1955	55	41.5
1956	41	41.5
1957	29	41.5
1958	44	41.5
1959	47	41.5
1960	47	36.2
1961	46	36.2
1962	31	36.2
1963	32	36.2
1964	44	36.2
1965	11	36.2
1966	39	36.2
1967	35	36.2
1968	31	36.2
1969	46	36.2
1970	49	40.4
1971	43	40.4
1972	22	40.4
1973	35	40.4
1974	52	40.4
1975	34	40.4
1976	38	40.4
1977	46	40.4
1978	45	40.4

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

First to last qualifying date each year at Rock Springs
Year	First date	Last date
1933	1933-06-16	1933-09-05
1934	1934-06-30	1934-08-28
1935	1935-06-12	1935-08-30
1936	1936-05-30	1936-08-26
1937	1937-06-21	1937-08-27
1938	1938-07-09	1938-08-24
1939	1939-06-13	1939-09-01
1940	1940-06-12	1940-09-02
1941	1941-05-12	1941-08-09
1949	1949-06-16	1949-08-22
1950	1950-06-30	1950-09-07
1951	1951-07-03	1951-08-18
1952	1952-06-09	1952-09-05
1953	1953-06-10	1953-09-14
1954	1954-05-19	1954-09-01
1955	1955-06-21	1955-09-08
1956	1956-05-31	1956-09-18
1957	1957-06-28	1957-08-24
1958	1958-05-27	1958-09-11
1959	1959-06-06	1959-09-11
1960	1960-06-03	1960-09-03
1961	1961-06-09	1961-08-28
1962	1962-06-24	1962-09-19
1963	1963-06-27	1963-09-12
1964	1964-05-20	1964-08-18
1965	1965-07-14	1965-08-12
1966	1966-06-19	1966-08-26
1967	1967-07-01	1967-09-03
1968	1968-06-18	1968-08-07
1969	1969-05-26	1969-08-27
1970	1970-06-22	1970-08-31
1971	1971-06-18	1971-08-27
1972	1972-06-30	1972-08-16
1973	1973-06-09	1973-08-26
1974	1974-06-13	1974-09-09
1975	1975-06-30	1975-08-30
1976	1976-06-08	1976-09-05
1977	1977-06-01	1977-09-07
1978	1978-06-09	1978-09-26

Every Fixed Threshold

Fixed thresholds at Rock Springs
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	39	63	1940	45
35 C (95 F): Days	21	8	1954	1
90 F (32.2 C): Days	39	35	1940	18
0 C (32 F): Ice days (max	39	69	1964	48
0 C (32 F): Frost days (min	39	223	1975	204
-10 C (14 F): Days with min	39	88	1937	64
-20 C (-4 F): Days with min	39	25	1960	12
-30 C (-22 F): Days with min	13	5	1972	1
10 mm (0.39 in): Days with 10 mm or more rain	38	8	1937	5
25 mm (0.98 in): Days with 25 mm or more rain	16	3	1973	3
50 mm (1.97 in): Days with 50 mm or more rain	3	1	1965	1
10 cm (3.9 in): Days with 10 cm or more snowfall	29	9	1975	7
25 cm (9.8 in): Days with 25 cm or more snowfall	6	1	1956	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1933.

Download the Data

Data for Rock Springs 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).

Rock Springs Threshold Days by Year (USC00487840)

Key Facts for Rock Springs Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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