Daily records
Page built 2026-10-18
Data as of 2025-12-31
Search
Built 2026-10-18 (18 October 2026)

Isaac Threshold Days by Year

4 fixed thresholds counted per year at Isaac (ASN00034030): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Isaac Thresholds

  • Isaac: days with 10 mm (0.39 in) or more of precipitation in 29 years, most in 1974 with 31.
  • Isaac: days with 25 mm (0.98 in) or more of precipitation in 29 years, most in 1974 with 14.
  • Isaac: days with 50 mm (1.97 in) or more of precipitation in 25 years, most in 1978 with 5.
  • Isaac: days with 100 mm (3.94 in) or more of precipitation in 5 years, most in 1975 with 2.
  • 4 fixed thresholds have at least one qualifying day at Isaac.
29 years with a qualifying day
Days with 10 mm (0.39 in) or more of precipitation per year at Isaac Days per year at Isaac with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 31 in 1974. 0102030401963: 141964: 171965: 111966: 131967: 201968: 261969: 101970: 171971: 181972: 131973: 231974: 311975: 141976: 221977: 191978: 221983: 241984: 111985: 211986: 141987: 161990: 131991: 161992: 121993: 151994: 91995: 201996: 121997: 101963196619691972197519781985199019931996
Days per year at Isaac with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 31 in 1974.
Days with 10 mm (0.39 in) or more of precipitation per year at Isaac
YearDaysDecade average
19631415.9
19641715.9
19651115.9
19661315.9
19672015.9
19682615.9
19691015.9
19701719.9
19711819.9
19721319.9
19732319.9
19743119.9
19751419.9
19762219.9
19771919.9
19782219.9
19832417.2
19841117.2
19852117.2
19861417.2
19871617.2
19901313.4
19911613.4
19921213.4
19931513.4
1994913.4
19952013.4
19961213.4
19971013.4
First to last qualifying date each year at Isaac For each year, a bar from the first to the last day at Isaac meeting 10 mm (0.39 in). 1963: 14 February 1963 to 8 December 19631964: 3 January 1964 to 27 December 19641965: 24 January 1965 to 15 December 19651966: 25 January 1966 to 10 December 19661967: 1 January 1967 to 25 December 19671968: 8 January 1968 to 26 December 19681969: 3 May 1969 to 25 December 19691970: 19 January 1970 to 9 December 19701971: 22 January 1971 to 27 December 19711972: 1 January 1972 to 30 December 19721973: 8 January 1973 to 25 December 19731974: 1 January 1974 to 15 November 19741975: 18 February 1975 to 12 December 19751976: 7 January 1976 to 28 December 19761977: 31 January 1977 to 23 December 19771978: 6 January 1978 to 22 December 19781983: 2 January 1983 to 30 December 19831984: 6 January 1984 to 9 November 19841985: 24 January 1985 to 18 December 19851986: 7 February 1986 to 23 October 19861987: 29 January 1987 to 31 December 19871990: 5 March 1990 to 31 December 19901991: 4 January 1991 to 12 December 19911992: 9 January 1992 to 19 December 19921993: 8 January 1993 to 17 December 19931994: 22 January 1994 to 5 December 19941995: 20 January 1995 to 12 December 19951996: 6 January 1996 to 4 December 19961997: 4 February 1997 to 15 December 199719631967197119751983198719931997JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day at Isaac meeting 10 mm (0.39 in).
First to last qualifying date each year at Isaac
YearFirst dateLast date
19631963-02-141963-12-08
19641964-01-031964-12-27
19651965-01-241965-12-15
19661966-01-251966-12-10
19671967-01-011967-12-25
19681968-01-081968-12-26
19691969-05-031969-12-25
19701970-01-191970-12-09
19711971-01-221971-12-27
19721972-01-011972-12-30
19731973-01-081973-12-25
19741974-01-011974-11-15
19751975-02-181975-12-12
19761976-01-071976-12-28
19771977-01-311977-12-23
19781978-01-061978-12-22
19831983-01-021983-12-30
19841984-01-061984-11-09
19851985-01-241985-12-18
19861986-02-071986-10-23
19871987-01-291987-12-31
19901990-03-051990-12-31
19911991-01-041991-12-12
19921992-01-091992-12-19
19931993-01-081993-12-17
19941994-01-221994-12-05
19951995-01-201995-12-12
19961996-01-061996-12-04
19971997-02-041997-12-15

Every Fixed Threshold

Fixed thresholds at Isaac
ThresholdYears with a qualifying dayMost days in a yearYearLatest year days
10 mm (0.39 in): Days with 10 mm or more rain2931197410
25 mm (0.98 in): Days with 25 mm or more rain291419741
50 mm (1.97 in): Days with 50 mm or more rain25519781
100 mm (3.94 in): Days with 100 mm or more rain5219751

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1963.

Download the Data

  • Data for Isaac 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 2026-10-16 (16 October 2026). Threshold counts are computed by this site.

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