Shamrock Threshold Days by Year (CA004027440)

16 fixed thresholds counted per year at Shamrock (CA004027440): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Shamrock Thresholds

Shamrock: days with a maximum temperature at or above 30 C (86 F) in 27 years, most in 1961 with 40.
Shamrock: days with a maximum temperature at or below 0 C (32 F) in 27 years, most in 1982 with 126.
Shamrock: nights with a minimum temperature at or below 0 C (32 F) in 27 years, most in 1961 with 217.
Shamrock: nights with a minimum temperature at or below -10 C (14 F) in 27 years, most in 1975 with 113.
16 fixed thresholds have at least one qualifying day at Shamrock.

Days at or above 30 C (86 F)

27 years with a qualifying day

Days per year at Shamrock with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 40 in 1961.

Days at or above 30 C (86 F) per year at Shamrock
Year	Days	Decade average
1957	18	21.3
1958	26	21.3
1959	20	21.3
1960	22	20.6
1961	40	20.6
1962	6	20.6
1963	12	20.6
1964	27	20.6
1965	13	20.6
1966	20	20.6
1967	32	20.6
1968	15	20.6
1969	19	20.6
1970	27	16.3
1971	25	16.3
1972	13	16.3
1973	18	16.3
1974	13	16.3
1975	13	16.3
1976	10	16.3
1977	7	16.3
1978	15	16.3
1979	22	16.3
1980	16	20
1981	22	20
1982	11	20
1983	31	20

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

First to last qualifying date each year at Shamrock
Year	First date	Last date
1957	1957-07-09	1957-10-01
1958	1958-05-11	1958-09-12
1959	1959-06-03	1959-08-10
1960	1960-05-12	1960-09-15
1961	1961-05-29	1961-08-31
1962	1962-06-25	1962-09-27
1963	1963-05-30	1963-09-30
1964	1964-05-17	1964-09-17
1965	1965-07-18	1965-08-12
1966	1966-05-26	1966-09-18
1967	1967-06-26	1967-09-06
1968	1968-06-19	1968-09-11
1969	1969-05-26	1969-09-13
1970	1970-06-03	1970-09-04
1971	1971-05-13	1971-09-11
1972	1972-05-17	1972-08-29
1973	1973-06-29	1973-08-22
1974	1974-06-17	1974-08-06
1975	1975-06-24	1975-09-16
1976	1976-07-17	1976-09-17
1977	1977-05-10	1977-07-23
1978	1978-05-15	1978-09-04
1979	1979-06-12	1979-09-16
1980	1980-04-20	1980-09-06
1981	1981-05-21	1981-09-19
1982	1982-07-30	1982-09-09
1983	1983-06-10	1983-09-26

Every Fixed Threshold

Fixed thresholds at Shamrock
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	27	40	1961	31
35 C (95 F): Days	22	9	1983	9
90 F (32.2 C): Days	26	28	1961	11
100 F (37.8 C): Days	6	2	1959	1
0 C (32 F): Ice days (max	27	126	1982	102
0 C (32 F): Frost days (min	27	217	1961	192
-10 C (14 F): Days with min	27	113	1975	84
-20 C (-4 F): Days with min	27	69	1978	30
-30 C (-22 F): Days with min	27	21	1982	12
-40 C (-40 F): Days with min	4	1	1968	1
20 C (68 F): Tropical nights (min	3	1	1973	1
10 mm (0.39 in): Days with 10 mm or more rain	27	16	1969	12
25 mm (0.98 in): Days with 25 mm or more rain	22	4	1963	1
50 mm (1.97 in): Days with 50 mm or more rain	5	1	1962	1
10 cm (3.9 in): Days with 10 cm or more snowfall	24	6	1982	4
25 cm (9.8 in): Days with 25 cm or more snowfall	1	1	1982	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1957.

Download the Data

Data for Shamrock 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).

Shamrock Threshold Days by Year (CA004027440)

Key Facts for Shamrock Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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