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

Palo Alto Threshold Days by Year (USC00046646)

10 fixed thresholds counted per year at Palo Alto (USC00046646): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Palo Alto Thresholds

  • Palo Alto: days with 10 mm (0.39 in) or more of precipitation in 55 years, most in 1982 with 24.
  • Palo Alto: days with 25 mm (0.98 in) or more of precipitation in 48 years, most in 1963 with 6.
  • Palo Alto: days with a maximum temperature at or above 30 C (86 F) in 45 years, most in 1996 with 49.
  • Palo Alto: days with a maximum temperature at or above 90 F (32.2 C) in 44 years, most in 1996 with 24.
  • 10 fixed thresholds have at least one qualifying day at Palo Alto.
45 years with a qualifying day
Days at or above 30 C (86 F) per year at Palo Alto Days per year at Palo Alto with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 49 in 1996. 02040601954: 211955: 251956: 201957: 241958: 231959: 211960: 131961: 251962: 81963: 131964: 181965: 101968: 241969: 181970: 301971: 221972: 151973: 211974: 171975: 251976: 301977: 151978: 271979: 261980: 131981: 211982: 151984: 331986: 51988: 221989: 181990: 81991: 131992: 101993: 81994: 111995: 271996: 491997: 301998: 282005: 62006: 182007: 162012: 182017: 30195419591964197119761981198919942005
Days per year at Palo Alto with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 49 in 1996.
Days at or above 30 C (86 F) per year at Palo Alto
YearDaysDecade average
19542122.3
19552522.3
19562022.3
19572422.3
19582322.3
19592122.3
19601316.1
19612516.1
1962816.1
19631316.1
19641816.1
19651016.1
19682416.1
19691816.1
19703022.8
19712222.8
19721522.8
19732122.8
19741722.8
19752522.8
19763022.8
19771522.8
19782722.8
19792622.8
19801318.1
19812118.1
19821518.1
19843318.1
1986518.1
19882218.1
19891818.1
1990820.4
19911320.4
19921020.4
1993820.4
19941120.4
19952720.4
19964920.4
19973020.4
19982820.4
2005613.3
20061813.3
20071613.3
20121824
20173024
First to last qualifying date each year at Palo Alto For each year, a bar from the first to the last day at Palo Alto meeting 30 C (86 F). 1954: 16 April 1954 to 15 October 19541955: 11 May 1955 to 11 November 19551956: 7 April 1956 to 30 September 19561957: 29 April 1957 to 22 September 19571958: 16 May 1958 to 11 October 19581959: 8 May 1959 to 23 October 19591960: 1 June 1960 to 5 October 19601961: 15 June 1961 to 17 October 19611962: 19 June 1962 to 17 September 19621963: 18 May 1963 to 27 September 19631964: 23 June 1964 to 20 October 19641965: 29 June 1965 to 25 October 19651968: 2 June 1968 to 27 October 19681969: 6 May 1969 to 26 September 19691970: 3 May 1970 to 2 October 19701971: 15 June 1971 to 13 October 19711972: 2 May 1972 to 23 August 19721973: 28 May 1973 to 29 September 19731974: 27 May 1974 to 1 October 19741975: 13 May 1975 to 21 October 19751976: 12 May 1976 to 14 October 19761977: 5 June 1977 to 8 September 19771978: 18 May 1978 to 14 October 19781979: 12 May 1979 to 13 September 19791980: 28 June 1980 to 4 October 19801981: 29 April 1981 to 29 August 19811982: 24 May 1982 to 13 September 19821984: 15 April 1984 to 28 September 19841986: 17 May 1986 to 31 July 19861988: 11 April 1988 to 18 October 19881989: 6 April 1989 to 9 October 19891990: 8 May 1990 to 4 October 19901991: 2 June 1991 to 22 October 19911992: 10 July 1992 to 11 October 19921993: 10 May 1993 to 18 July 19931994: 10 June 1994 to 17 September 19941995: 22 June 1995 to 4 October 19951996: 30 April 1996 to 9 October 19961997: 16 May 1997 to 17 October 19971998: 22 April 1998 to 14 September 19982005: 31 August 2005 to 1 October 20052006: 15 May 2006 to 27 September 20062007: 8 May 2007 to 28 September 20072012: 21 April 2012 to 19 October 20122017: 2 May 2017 to 25 October 201719541960196819741980198919952007JanFebMarAprMayJunJulAugSepOctNovDec
For each year, a bar from the first to the last day at Palo Alto meeting 30 C (86 F).
First to last qualifying date each year at Palo Alto
YearFirst dateLast date
19541954-04-161954-10-15
19551955-05-111955-11-11
19561956-04-071956-09-30
19571957-04-291957-09-22
19581958-05-161958-10-11
19591959-05-081959-10-23
19601960-06-011960-10-05
19611961-06-151961-10-17
19621962-06-191962-09-17
19631963-05-181963-09-27
19641964-06-231964-10-20
19651965-06-291965-10-25
19681968-06-021968-10-27
19691969-05-061969-09-26
19701970-05-031970-10-02
19711971-06-151971-10-13
19721972-05-021972-08-23
19731973-05-281973-09-29
19741974-05-271974-10-01
19751975-05-131975-10-21
19761976-05-121976-10-14
19771977-06-051977-09-08
19781978-05-181978-10-14
19791979-05-121979-09-13
19801980-06-281980-10-04
19811981-04-291981-08-29
19821982-05-241982-09-13
19841984-04-151984-09-28
19861986-05-171986-07-31
19881988-04-111988-10-18
19891989-04-061989-10-09
19901990-05-081990-10-04
19911991-06-021991-10-22
19921992-07-101992-10-11
19931993-05-101993-07-18
19941994-06-101994-09-17
19951995-06-221995-10-04
19961996-04-301996-10-09
19971997-05-161997-10-17
19981998-04-221998-09-14
20052005-08-312005-10-01
20062006-05-152006-09-27
20072007-05-082007-09-28
20122012-04-212012-10-19
20172017-05-022017-10-25

Every Fixed Threshold

Fixed thresholds at Palo Alto
ThresholdYears with a qualifying dayMost days in a yearYearLatest year days
30 C (86 F): Days4549199630
35 C (95 F): Days38919816
40 C (104 F): Days7219722
90 F (32.2 C): Days4424199616
100 F (37.8 C): Days21419763
0 C (32 F): Frost days (min424019934
20 C (68 F): Tropical nights (min4119571
10 mm (0.39 in): Days with 10 mm or more rain5524198220
25 mm (0.98 in): Days with 25 mm or more rain48619633
50 mm (1.97 in): Days with 50 mm or more rain5119551

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1954.

Download the Data

  • Data for Palo Alto 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).