Daily records
Page built 2026-10-19
Data as of 2025-12-31
Search
Built 2026-10-19 (19 October 2026)

Groton Threshold Days by Year (CA003042960)

5 fixed thresholds counted per year at Groton (CA003042960): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Groton Thresholds

  • Groton: days with 10 mm (0.39 in) or more of precipitation in 24 years, most in 1951 with 16.
  • Groton: days with 10 cm (3.9 in) or more of snowfall in 23 years, most in 1933 with 8.
  • Groton: days with 25 mm (0.98 in) or more of precipitation in 13 years, most in 1956 with 4.
  • Groton: days with 25 cm (9.8 in) or more of snowfall in 3 years, most in 1933 with 1.
  • 5 fixed thresholds have at least one qualifying day at Groton.
24 years with a qualifying day
Days with 10 mm (0.39 in) or more of precipitation per year at Groton Days per year at Groton with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 16 in 1951. 051015201932: 141933: 121934: 61935: 81936: 101937: 111939: 101940: 121941: 111942: 81943: 51944: 61945: 51946: 91947: 81948: 81949: 51950: 91951: 161952: 111954: 121955: 141956: 91960: 819321935193919421945194819511955
Days per year at Groton with 10 mm (0.39 in) or more of precipitation, with the decade average as a line. The most was 16 in 1951.
Days with 10 mm (0.39 in) or more of precipitation per year at Groton
YearDaysDecade average
19321410.1
19331210.1
1934610.1
1935810.1
19361010.1
19371110.1
19391010.1
1940127.7
1941117.7
194287.7
194357.7
194467.7
194557.7
194697.7
194787.7
194887.7
194957.7
1950911.8
19511611.8
19521111.8
19541211.8
19551411.8
1956911.8
196088
First to last qualifying date each year at Groton For each year, a bar from the first to the last day at Groton meeting 10 mm (0.39 in). 1932: 21 April 1932 to 13 November 19321933: 3 April 1933 to 10 December 19331934: 23 January 1934 to 20 November 19341935: 7 April 1935 to 23 December 19351936: 27 March 1936 to 7 December 19361937: 26 January 1937 to 12 November 19371939: 23 May 1939 to 21 December 19391940: 19 February 1940 to 1 November 19401941: 24 February 1941 to 25 December 19411942: 20 February 1942 to 20 October 19421943: 15 January 1943 to 1 June 19431944: 21 May 1944 to 21 December 19441945: 2 January 1945 to 20 December 19451946: 1 April 1946 to 25 November 19461947: 2 March 1947 to 18 September 19471948: 4 February 1948 to 22 September 19481949: 17 May 1949 to 5 October 19491950: 12 January 1950 to 20 October 19501951: 4 March 1951 to 18 December 19511952: 23 January 1952 to 23 November 19521954: 10 May 1954 to 2 October 19541955: 22 March 1955 to 25 July 19551956: 22 February 1956 to 29 August 19561960: 8 January 1960 to 26 November 196019321935193919421945194819511955JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day at Groton meeting 10 mm (0.39 in).
First to last qualifying date each year at Groton
YearFirst dateLast date
19321932-04-211932-11-13
19331933-04-031933-12-10
19341934-01-231934-11-20
19351935-04-071935-12-23
19361936-03-271936-12-07
19371937-01-261937-11-12
19391939-05-231939-12-21
19401940-02-191940-11-01
19411941-02-241941-12-25
19421942-02-201942-10-20
19431943-01-151943-06-01
19441944-05-211944-12-21
19451945-01-021945-12-20
19461946-04-011946-11-25
19471947-03-021947-09-18
19481948-02-041948-09-22
19491949-05-171949-10-05
19501950-01-121950-10-20
19511951-03-041951-12-18
19521952-01-231952-11-23
19541954-05-101954-10-02
19551955-03-221955-07-25
19561956-02-221956-08-29
19601960-01-081960-11-26

Every Fixed Threshold

Fixed thresholds at Groton
ThresholdYears with a qualifying dayMost days in a yearYearLatest year days
10 mm (0.39 in): Days with 10 mm or more rain241619518
25 mm (0.98 in): Days with 25 mm or more rain13419564
50 mm (1.97 in): Days with 50 mm or more rain2119511
10 cm (3.9 in): Days with 10 cm or more snowfall23819334
25 cm (9.8 in): Days with 25 cm or more snowfall3119331

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1932.

Download the Data

  • Data for Groton 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).