Built 2026-10-19 (19 October 2026)

Shannon Threshold Days by Year (EIM00003962)

6 fixed thresholds counted per year at Shannon (EIM00003962): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Shannon Thresholds

  • Shannon: days with 10 mm (0.39 in) or more of precipitation in 17 years, most in 1979 with 30.
  • Shannon: days with 25 mm (0.98 in) or more of precipitation in 14 years, most in 1975 with 2.
  • Shannon: days with a maximum temperature at or below 0 C (32 F) in 2 years, most in 1980 with 1.
  • 6 fixed thresholds have at least one qualifying day at Shannon.
17 years with a qualifying day
Days with 10 mm (0.39 in) or more of precipitation per year at Shannon Days per year at Shannon with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 30 in 1979. 0102030401973: 211974: 171975: 191976: 231977: 201979: 301980: 191981: 201999: 382017: 232018: 252019: 302020: 322021: 262023: 282024: 232025: 17197319751977198019992018202020232025
Days per year at Shannon with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 30 in 1979.
Days with 10 mm (0.39 in) or more of precipitation per year at Shannon
YearDaysDecade average
19732121.7
19741721.7
19751921.7
19762321.7
19772021.7
19793021.7
19801919.5
19812019.5
19993838
20172326
20182526
20193026
20203225.2
20212625.2
20232825.2
20242325.2
20251725.2
First to last qualifying date each year at Shannon For each year, a bar from the first to the last day at Shannon meeting 10 mm (0.39 in). 1973: 13 January 1973 to 7 December 19731974: 3 January 1974 to 14 November 19741975: 15 January 1975 to 31 December 19751976: 1 January 1976 to 30 December 19761977: 4 January 1977 to 26 December 19771979: 10 January 1979 to 26 December 19791980: 31 January 1980 to 25 December 19801981: 14 January 1981 to 26 December 19811999: 2 January 1999 to 30 December 19992017: 1 January 2017 to 30 December 20172018: 11 January 2018 to 23 December 20182019: 5 February 2019 to 17 December 20192020: 9 February 2020 to 27 December 20202021: 19 January 2021 to 30 December 20212023: 10 January 2023 to 30 December 20232024: 1 January 2024 to 31 December 20242025: 1 January 2025 to 17 July 2025197319761980201720202024JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day at Shannon meeting 10 mm (0.39 in).
First to last qualifying date each year at Shannon
YearFirst dateLast date
19731973-01-131973-12-07
19741974-01-031974-11-14
19751975-01-151975-12-31
19761976-01-011976-12-30
19771977-01-041977-12-26
19791979-01-101979-12-26
19801980-01-311980-12-25
19811981-01-141981-12-26
19991999-01-021999-12-30
20172017-01-012017-12-30
20182018-01-112018-12-23
20192019-02-052019-12-17
20202020-02-092020-12-27
20212021-01-192021-12-30
20232023-01-102023-12-30
20242024-01-012024-12-31
20252025-01-012025-07-17

Every Fixed Threshold

Fixed thresholds at Shannon
ThresholdYears with a qualifying dayMost days in a yearYearLatest year days
0 C (32 F): Ice days (max2119801
0 C (32 F): Frost days (min10n/a4
10 mm (0.39 in): Days with 10 mm or more rain1730197917
25 mm (0.98 in): Days with 25 mm or more rain14219753
50 mm (1.97 in): Days with 50 mm or more rain10n/a1
100 mm (3.94 in): Days with 100 mm or more rain10n/a1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1980.

Download the Data

  • Data for Shannon 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 . Last revised (2025-12-31).