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Palos Altos Weather Records (MXN00012063)

Record envelope, standing records and threshold days for Palos Altos (MXN00012063), Mexico, with 51 years of record.

Key Facts for Palos Altos

  • Palos Altos (MXN00012063) is a weather station in Mexico at 18.35 latitude and -100.27 longitude, 380 m (1,246 ft) above sea level.
  • The station reports from 1962 to 2012, 51 years of record.
  • 1,464 records set at Palos Altos still stand.
  • Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
  • Palos Altos set a daily record precipitation of 37.8 mm (1.5 in) on 27 September 2012.

About the Station

  • Location: Mexico, 18.35 latitude, -100.27 longitude.
  • Elevation: 380 m (1,246 ft).
  • Period of record: 1962 to 2012, 51 years.
  • Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

0 days at or beyond a record
Daily record high and record low at Palos Altos, with 2026 drawn through them The band shows the record high and record low for each calendar day at Palos Altos. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius. 01020304050 JanFebMarAprMayJunJulAugSepOctNovDec
The band shows the record high and record low for each calendar day at Palos Altos. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Palos Altos, with 2026 drawn through them
MonthHighest record highLowest record low2026 highest maximum2026 lowest minimum
Jan38.9 C (102.0 F)7.2 C (45.0 F)n/an/a
Feb41.1 C (106.0 F)9.4 C (48.9 F)n/an/a
Mar42.8 C (109.0 F)11.1 C (52.0 F)n/an/a
Apr45.0 C (113.0 F)15.0 C (59.0 F)n/an/a
May45.0 C (113.0 F)15.6 C (60.1 F)n/an/a
Jun44.4 C (111.9 F)13.9 C (57.0 F)n/an/a
Jul40.6 C (105.1 F)15.0 C (59.0 F)n/an/a
Aug39.4 C (102.9 F)14.4 C (57.9 F)n/an/a
Sep40.0 C (104.0 F)10.0 C (50.0 F)n/an/a
Oct39.4 C (102.9 F)12.8 C (55.0 F)n/an/a
Nov38.3 C (100.9 F)6.1 C (43.0 F)n/an/a
Dec38.9 C (102.0 F)10.0 C (50.0 F)n/an/a

Which Years Hold Standing Records

1,464 standing records
Standing records at Palos Altos by the year they were set 1,464 records at Palos Altos still stand. 1970 holds the most, with 109. 0501001501962: 291963: 141964: 701965: 171966: 371967: 101968: 311969: 841970: 1091971: 231972: 371973: 301974: 111975: 101976: 101977: 131978: 371979: 451980: 341981: 241982: 381983: 341984: 61985: 81986: 311987: 281988: 121989: 71990: 31991: 61992: 301993: 101994: 91995: 81996: 221997: 391998: 261999: 112000: 62001: 112002: 352003: 642004: 692005: 122006: 922007: 132008: 492009: 212010: 552011: 302012: 4196219681974198019861992199820042010
1,464 records at Palos Altos still stand. 1970 holds the most, with 109.
Standing records at Palos Altos by the year they were set
Year setStanding records
196229
196314
196470
196517
196637
196710
196831
196984
1970109
197123
197237
197330
197411
197510
197610
197713
197837
197945
198034
198124
198238
198334
19846
19858
198631
198728
198812
19897
19903
19916
199230
199310
19949
19958
199622
199739
199826
199911
20006
200111
200235
200364
200469
200512
200692
200713
200849
200921
201055
201130
20124

All-Time Record Progression

3 new records
When Palos Altos set new all-time records 3 all-time records were set at Palos Altos between 14 August 1994 and 22 June 2005. Each dot is a new record. Record daily precipitationRecord low minimum temperature14 August 1994: Record daily precipitation 101.9 mm (4.0 in)24 November 2002: Record low minimum temperature 6.1 C (43.0 F)22 June 2005: Record daily precipitation 102.4 mm (4.0 in)199520002005
3 all-time records were set at Palos Altos between 14 August 1994 and 22 June 2005. Each dot is a new record.
When Palos Altos set new all-time records
DateKindDetail
1994-08-14Record daily precipitationRecord daily precipitation 101.9 mm (4.0 in)
2002-11-24Record low minimum temperatureRecord low minimum temperature 6.1 C (43.0 F)
2005-06-22Record daily precipitationRecord daily precipitation 102.4 mm (4.0 in)

Wettest Day of Each Month

Jun: 102.4 mm (4.0 in)
Record daily precipitation for each month at Palos Altos The wettest day on record for each calendar month at Palos Altos. The most was 102.4 mm (4.0 in) on 22 June 2005. 050100150 Jan: 61.2 mm (2.4 in), 25 January 1980 Jan Feb: 74.9 mm (2.9 in), 3 February 2010 Feb Mar: 33.0 mm (1.3 in), 3 March 2001 Mar Apr: 37.8 mm (1.5 in), 2 April 1966 Apr May: 57.2 mm (2.3 in), 31 May 1997 May Jun: 102.4 mm (4.0 in), 22 June 2005 Jun Jul: 88.9 mm (3.5 in), 3 July 1993 Jul Aug: 101.9 mm (4.0 in), 14 August 1994 Aug Sep: 95.8 mm (3.8 in), 16 September 1966 Sep Oct: 78.5 mm (3.1 in), 5 October 1992 Oct Nov: 49.3 mm (1.9 in), 2 November 2009 Nov Dec: 14.0 mm (0.6 in), 19 December 2001 Dec
The wettest day on record for each calendar month at Palos Altos. The most was 102.4 mm (4.0 in) on 22 June 2005.
Record daily precipitation for each month at Palos Altos
MonthRecord daily precipitation (mm)Date
Jan61.2 mm (2.4 in)25 January 1980
Feb74.9 mm (2.9 in)3 February 2010
Mar33.0 mm (1.3 in)3 March 2001
Apr37.8 mm (1.5 in)2 April 1966
May57.2 mm (2.3 in)31 May 1997
Jun102.4 mm (4.0 in)22 June 2005
Jul88.9 mm (3.5 in)3 July 1993
Aug101.9 mm (4.0 in)14 August 1994
Sep95.8 mm (3.8 in)16 September 1966
Oct78.5 mm (3.1 in)5 October 1992
Nov49.3 mm (1.9 in)2 November 2009
Dec14.0 mm (0.6 in)19 December 2001

Period of Record Coverage

1962 to 2012
Days with data per year at Palos Altos 51 years of record at Palos Altos, 1962 to 2012. 8 years have data for under 90 percent of days and are left out of rankings: 1962, 1989, 1991, 1996, 1997, 2005, 2007, 2012. 1962: 268 of 365 days1963: 334 of 365 days1964: 366 of 366 days1965: 365 of 365 days1966: 365 of 365 days1967: 363 of 365 days1968: 366 of 366 days1969: 362 of 365 days1970: 365 of 365 days1971: 365 of 365 days1972: 366 of 366 days1973: 365 of 365 days1974: 365 of 365 days1975: 365 of 365 days1976: 366 of 366 days1977: 365 of 365 days1978: 365 of 365 days1979: 365 of 365 days1980: 366 of 366 days1981: 365 of 365 days1982: 365 of 365 days1983: 364 of 365 days1984: 366 of 366 days1985: 364 of 365 days1986: 363 of 365 days1987: 365 of 365 days1988: 335 of 366 days1989: 208 of 365 days1990: 334 of 365 days1991: 304 of 365 days1992: 364 of 366 days1993: 350 of 365 days1994: 336 of 365 days1995: 333 of 365 days1996: 326 of 366 days1997: 327 of 365 days1998: 345 of 365 days1999: 364 of 365 days2000: 366 of 366 days2001: 330 of 365 days2002: 365 of 365 days2003: 365 of 365 days2004: 366 of 366 days2005: 212 of 365 days2006: 365 of 365 days2007: 212 of 365 days2008: 366 of 366 days2009: 365 of 365 days2010: 365 of 365 days2011: 365 of 365 days2012: 324 of 366 days19701980199020002010
51 years of record at Palos Altos, 1962 to 2012. 8 years have data for under 90 percent of days and are left out of rankings: 1962, 1989, 1991, 1996, 1997, 2005, 2007, 2012.
Days with data per year at Palos Altos
YearDays with dataShare of yearComplete
196226873%No
196333492%Yes
1964366100%Yes
1965365100%Yes
1966365100%Yes
196736399%Yes
1968366100%Yes
196936299%Yes
1970365100%Yes
1971365100%Yes
1972366100%Yes
1973365100%Yes
1974365100%Yes
1975365100%Yes
1976366100%Yes
1977365100%Yes
1978365100%Yes
1979365100%Yes
1980366100%Yes
1981365100%Yes
1982365100%Yes
1983364100%Yes
1984366100%Yes
1985364100%Yes
198636399%Yes
1987365100%Yes
198833592%Yes
198920857%No
199033492%Yes
199130483%No
199236499%Yes
199335096%Yes
199433692%Yes
199533391%Yes
199632689%No
199732790%No
199834595%Yes
1999364100%Yes
2000366100%Yes
200133090%Yes
2002365100%Yes
2003365100%Yes
2004366100%Yes
200521258%No
2006365100%Yes
200721258%No
2008366100%Yes
2009365100%Yes
2010365100%Yes
2011365100%Yes
201232489%No

Latest Records

20
Latest records at Palos Altos
DateStationRecordValueBeat old record byOld record stoodSignificance
27 September 2012Palos Altos, MXdaily rain37.8 mm (1.5 in)1.0 mm (0.04 in)48 years19 of 100 (Routine)
1 August 2012Palos Altos, MXdaily rain91.9 mm (3.6 in)36.0 mm (1.4 in)47 years42 of 100 (Notable)
18 May 2012Palos Altos, MXdaily high max43.9 C (111.0 F)0.6 C (1.1 F)46 years20 of 100 (Routine)
17 May 2012Palos Altos, MXall-time high max (Tie)45.0 C (113.0 F)tie30 years8 of 100 (Routine)
5 April 2012Palos Altos, MXdaily low min (Tie)18.3 C (64.9 F)tie29 years3 of 100 (Routine)
12 February 2012Palos Altos, MXmonthly low max (Tie)26.1 C (79.0 F)tie20 years5 of 100 (Routine)
10 February 2012Palos Altos, MXdaily rain1.8 mm (0.07 in)1.8 mm (0.07 in)48 years20 of 100 (Routine)
10 February 2012Palos Altos, MXdaily low max28.3 C (82.9 F)1.7 C (3.1 F)20 years18 of 100 (Routine)
9 February 2012Palos Altos, MXdaily rain3.6 mm (0.14 in)3.6 mm (0.14 in)48 years20 of 100 (Routine)
2 December 2011Palos Altos, MXdaily low min12.2 C (54.0 F)0.6 C (1.1 F)44 years20 of 100 (Routine)
1 December 2011Palos Altos, MXdaily low min11.7 C (53.1 F)1.1 C (2.0 F)44 years22 of 100 (Routine)
30 November 2011Palos Altos, MXdaily low min (Tie)12.8 C (55.0 F)tie4 years1 of 100 (Routine)
27 November 2011Palos Altos, MXdaily rain2.3 mm (0.09 in)1.5 mm (0.06 in)24 years13 of 100 (Routine)
3 November 2011Palos Altos, MXdaily low min (Tie)14.4 C (57.9 F)tie25 years3 of 100 (Routine)
2 November 2011Palos Altos, MXdaily low min13.3 C (55.9 F)1.7 C (3.1 F)9 years13 of 100 (Routine)
2 November 2011Palos Altos, MXdaily low max (Tie)30.0 C (86.0 F)tie18 years2 of 100 (Routine)
25 October 2011Palos Altos, MXdaily low min15.0 C (59.0 F)0.6 C (1.1 F)12 years11 of 100 (Routine)
25 October 2011Palos Altos, MXdaily low max (Tie)28.9 C (84.0 F)tie4 years1 of 100 (Routine)
24 October 2011Palos Altos, MXdaily low min15.0 C (59.0 F)1.1 C (2.0 F)4 years11 of 100 (Routine)
21 October 2011Palos Altos, MXdaily low min (Tie)16.7 C (62.1 F)tie8 years1 of 100 (Routine)

Climate Trend

35 complete years, 1964 to 2011
Annual mean temperature at Palos Altos as warming stripes, 1964 to 2011 One stripe for each of 35 complete years at Palos Altos, 1964 to 2011. Blue stripes are years cooler than the station's own mean of 26.9 C (80.4 F); red stripes are warmer. The coolest year was 2004, at 24.0 C (75.2 F), and the warmest was 1969, at 28.8 C (83.8 F). The strongest colour marks a difference of 2.9 C (5.2 F). 1964: 27.5 C, +0.6 C from the station mean1965: 27.8 C, +1.0 C from the station mean1966: 27.7 C, +0.8 C from the station mean1967: 27.6 C, +0.7 C from the station mean1968: 27.8 C, +1.0 C from the station mean1969: 28.8 C, +1.9 C from the station mean1970: 27.8 C, +0.9 C from the station mean1971: 27.9 C, +1.0 C from the station mean1972: 28.1 C, +1.2 C from the station mean1973: 27.6 C, +0.7 C from the station mean1974: 27.3 C, +0.5 C from the station mean1975: 27.0 C, +0.1 C from the station mean1976: 27.1 C, +0.2 C from the station mean1977: 27.2 C, +0.4 C from the station mean1978: 28.0 C, +1.1 C from the station mean1979: 28.1 C, +1.2 C from the station mean1980: 27.6 C, +0.7 C from the station mean1981: 27.3 C, +0.4 C from the station mean1982: 28.0 C, +1.1 C from the station mean1983: 27.3 C, +0.4 C from the station mean1984: 27.1 C, +0.3 C from the station mean1985: 27.4 C, +0.5 C from the station mean1986: 27.3 C, +0.4 C from the station mean1987: 27.9 C, +1.0 C from the station mean1992: 26.9 C, 0.0 C from the station mean1999: 27.5 C, +0.6 C from the station mean2000: 27.0 C, +0.1 C from the station mean2002: 25.4 C, -1.4 C from the station mean2003: 24.4 C, -2.5 C from the station mean2004: 24.0 C, -2.9 C from the station mean2006: 24.3 C, -2.6 C from the station mean2008: 24.3 C, -2.6 C from the station mean2009: 24.9 C, -2.0 C from the station mean2010: 24.5 C, -2.4 C from the station mean2011: 24.6 C, -2.3 C from the station mean1964197019751980198519901995200020052010
One stripe for each of 35 complete years at Palos Altos, 1964 to 2011. Blue stripes are years cooler than the station's own mean of 26.9 C (80.4 F); red stripes are warmer. The coolest year was 2004, at 24.0 C (75.2 F), and the warmest was 1969, at 28.8 C (83.8 F). The strongest colour marks a difference of 2.9 C (5.2 F).
Annual mean temperature at Palos Altos as warming stripes, 1964 to 2011
YearAnnual mean temperatureDifference from the station mean
196427.5 C+0.61 C
196527.8 C+0.96 C
196627.7 C+0.84 C
196727.6 C+0.68 C
196827.8 C+0.96 C
196928.8 C+1.91 C
197027.8 C+0.92 C
197127.9 C+0.98 C
197228.1 C+1.19 C
197327.6 C+0.75 C
197427.3 C+0.46 C
197527.0 C+0.13 C
197627.1 C+0.19 C
197727.2 C+0.36 C
197828.0 C+1.08 C
197928.1 C+1.18 C
198027.6 C+0.72 C
198127.3 C+0.41 C
198228.0 C+1.14 C
198327.3 C+0.42 C
198427.1 C+0.26 C
198527.4 C+0.52 C
198627.3 C+0.43 C
198727.9 C+0.99 C
199226.9 C0.00 C
199927.5 C+0.58 C
200027.0 C+0.14 C
200225.4 C-1.43 C
200324.4 C-2.45 C
200424.0 C-2.86 C
200624.3 C-2.62 C
200824.3 C-2.59 C
200924.9 C-1.95 C
201024.5 C-2.42 C
201124.6 C-2.32 C

The annual mean temperature here has fallen by 0.8 C (0.6 to 0.9) per decade over 1964 to 2011. In Fahrenheit: 1.4 F (1.1 to 1.7) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Palos Altos
MeasurePer decade (C)Per decade (F)PeriodComplete yearsReading
Annual mean temperature-0.8 C (-0.9 to -0.6) per decade-1.4 F (-1.7 to -1.1) per decade1964 to 201135Fall
Mean daily maximum-0.7 C (-0.9 to -0.5) per decade-1.3 F (-1.7 to -0.9) per decade1964 to 201135Fall
Mean daily minimum-0.8 C (-1.0 to -0.6) per decade-1.5 F (-1.8 to -1.2) per decade1964 to 201135Fall

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1962 to 2012
Yearly extremes at Palos Altos: the record and the median year
MeasureRecordYear of the recordMedian yearYears with a value
Hottest day (TXx)45.0 C (113.0 F)198242.8 C (109.0 F)51
Coldest night (TNn)6.1 C (43.0 F)200210.6 C (51.1 F)51
Wettest day (Rx1day)102.4 mm (4.0 in)200566.3 mm (2.6 in)51
Wettest five days (Rx5day)221.1 mm (8.7 in)1966143.3 mm (5.6 in)51
Longest dry spell (CDD)168 days2005107 days51

Hottest day (TXx)

Hottest day (TXx) at Palos Altos by year The hottest day of the year at Palos Altos, 1962 to 2012. The record is 45.0 C (113.0 F) in 1982, marked on the chart; the median year is 42.8 C (109.0 F). 384042444619701980199020002010Record: 45.0 C (113.0 F) in 1982
The hottest day of the year at Palos Altos, 1962 to 2012. The record is 45.0 C (113.0 F) in 1982, marked on the chart; the median year is 42.8 C (109.0 F).
Hottest day (TXx) at Palos Altos by year
YearHottest day (TXx)
196241.7 C (107.1 F)
196341.1 C (106.0 F)
196442.8 C (109.0 F)
196542.8 C (109.0 F)
196643.3 C (109.9 F)
196742.8 C (109.0 F)
196841.7 C (107.1 F)
196944.4 C (111.9 F)
197043.3 C (109.9 F)
197142.8 C (109.0 F)
197242.8 C (109.0 F)
197342.8 C (109.0 F)
197441.7 C (107.1 F)
197541.1 C (106.0 F)
197643.3 C (109.9 F)
197741.7 C (107.1 F)
197842.8 C (109.0 F)
197941.7 C (107.1 F)
198042.8 C (109.0 F)
198142.2 C (108.0 F)
198245.0 C (113.0 F)
198343.3 C (109.9 F)
198445.0 C (113.0 F)
198542.8 C (109.0 F)
198643.3 C (109.9 F)
198742.8 C (109.0 F)
198843.3 C (109.9 F)
198942.8 C (109.0 F)
199042.2 C (108.0 F)
199143.3 C (109.9 F)
199241.7 C (107.1 F)
199343.3 C (109.9 F)
199442.8 C (109.0 F)
199542.2 C (108.0 F)
199641.7 C (107.1 F)
199743.3 C (109.9 F)
199844.4 C (111.9 F)
199942.8 C (109.0 F)
200042.8 C (109.0 F)
200142.2 C (108.0 F)
200242.2 C (108.0 F)
200341.7 C (107.1 F)
200438.9 C (102.0 F)
200540.0 C (104.0 F)
200639.4 C (102.9 F)
200739.4 C (102.9 F)
200838.9 C (102.0 F)
200938.9 C (102.0 F)
201041.1 C (106.0 F)
201139.4 C (102.9 F)
201245.0 C (113.0 F)

Coldest night (TNn)

Coldest night (TNn) at Palos Altos by year The coldest night of the year at Palos Altos, 1962 to 2012. The record is 6.1 C (43.0 F) in 2002, marked on the chart; the median year is 10.6 C (51.1 F). 57.51012.51519701980199020002010Record: 6.1 C (43.0 F) in 2002
The coldest night of the year at Palos Altos, 1962 to 2012. The record is 6.1 C (43.0 F) in 2002, marked on the chart; the median year is 10.6 C (51.1 F).
Coldest night (TNn) at Palos Altos by year
YearColdest night (TNn)
196211.7 C (53.1 F)
196311.1 C (52.0 F)
196411.7 C (53.1 F)
196510.6 C (51.1 F)
196611.1 C (52.0 F)
196710.6 C (51.1 F)
196811.7 C (53.1 F)
196911.7 C (53.1 F)
197010.0 C (50.0 F)
197110.0 C (50.0 F)
197210.6 C (51.1 F)
197310.6 C (51.1 F)
197410.6 C (51.1 F)
197511.1 C (52.0 F)
197611.7 C (53.1 F)
197710.6 C (51.1 F)
197813.9 C (57.0 F)
197911.7 C (53.1 F)
198010.0 C (50.0 F)
198111.1 C (52.0 F)
198210.0 C (50.0 F)
19838.9 C (48.0 F)
198411.7 C (53.1 F)
198510.0 C (50.0 F)
19867.2 C (45.0 F)
19879.4 C (48.9 F)
198811.1 C (52.0 F)
198911.1 C (52.0 F)
199011.7 C (53.1 F)
199110.0 C (50.0 F)
199210.0 C (50.0 F)
199310.0 C (50.0 F)
199415.0 C (59.0 F)
199511.7 C (53.1 F)
199610.0 C (50.0 F)
199712.2 C (54.0 F)
199810.0 C (50.0 F)
199911.1 C (52.0 F)
200013.9 C (57.0 F)
200111.7 C (53.1 F)
20026.1 C (43.0 F)
200310.6 C (51.1 F)
200410.0 C (50.0 F)
200511.7 C (53.1 F)
20068.9 C (48.0 F)
200713.3 C (55.9 F)
200810.0 C (50.0 F)
200910.6 C (51.1 F)
201010.0 C (50.0 F)
201110.6 C (51.1 F)
201212.2 C (54.0 F)

Wettest day (Rx1day)

Wettest day (Rx1day) at Palos Altos by year The wettest day of the year at Palos Altos, 1962 to 2012. The record is 102.4 mm (4.0 in) in 2005, marked on the chart; the median year is 66.3 mm (2.6 in). 025507510012519701980199020002010Record: 102.4 mm (4.0 in) in 2005
The wettest day of the year at Palos Altos, 1962 to 2012. The record is 102.4 mm (4.0 in) in 2005, marked on the chart; the median year is 66.3 mm (2.6 in).
Wettest day (Rx1day) at Palos Altos by year
YearWettest day (Rx1day)
196293.0 mm (3.7 in)
196365.3 mm (2.6 in)
196463.8 mm (2.5 in)
196555.9 mm (2.2 in)
196695.8 mm (3.8 in)
196769.9 mm (2.8 in)
196863.5 mm (2.5 in)
196953.8 mm (2.1 in)
197089.4 mm (3.5 in)
197160.5 mm (2.4 in)
197262.0 mm (2.4 in)
197391.7 mm (3.6 in)
197484.8 mm (3.3 in)
197546.0 mm (1.8 in)
197662.2 mm (2.4 in)
197793.0 mm (3.7 in)
197886.9 mm (3.4 in)
197971.9 mm (2.8 in)
198068.8 mm (2.7 in)
198174.9 mm (2.9 in)
198270.9 mm (2.8 in)
198366.3 mm (2.6 in)
198452.1 mm (2.1 in)
198556.9 mm (2.2 in)
198654.4 mm (2.1 in)
198751.6 mm (2.0 in)
198852.6 mm (2.1 in)
198965.3 mm (2.6 in)
199080.0 mm (3.1 in)
199173.7 mm (2.9 in)
199282.3 mm (3.2 in)
199388.9 mm (3.5 in)
1994101.9 mm (4.0 in)
199550.8 mm (2.0 in)
199653.6 mm (2.1 in)
199773.4 mm (2.9 in)
199866.3 mm (2.6 in)
199963.5 mm (2.5 in)
200043.2 mm (1.7 in)
200162.0 mm (2.4 in)
200236.3 mm (1.4 in)
200365.3 mm (2.6 in)
200476.2 mm (3.0 in)
2005102.4 mm (4.0 in)
200679.2 mm (3.1 in)
200720.8 mm (0.8 in)
200857.9 mm (2.3 in)
200949.3 mm (1.9 in)
201074.9 mm (2.9 in)
201174.7 mm (2.9 in)
201291.9 mm (3.6 in)

Wettest five days (Rx5day)

Wettest five days (Rx5day) at Palos Altos by year The wettest five days of the year at Palos Altos, 1962 to 2012. The record is 221.1 mm (8.7 in) in 1966, marked on the chart; the median year is 143.3 mm (5.6 in). 05010015020025019701980199020002010Record: 221.1 mm (8.7 in) in 1966
The wettest five days of the year at Palos Altos, 1962 to 2012. The record is 221.1 mm (8.7 in) in 1966, marked on the chart; the median year is 143.3 mm (5.6 in).
Wettest five days (Rx5day) at Palos Altos by year
YearWettest five days (Rx5day)
1962143.0 mm (5.6 in)
1963144.9 mm (5.7 in)
1964151.7 mm (6.0 in)
1965134.1 mm (5.3 in)
1966221.1 mm (8.7 in)
1967162.9 mm (6.4 in)
1968171.5 mm (6.8 in)
1969117.4 mm (4.6 in)
1970184.9 mm (7.3 in)
1971116.2 mm (4.6 in)
1972150.2 mm (5.9 in)
1973140.9 mm (5.5 in)
1974152.6 mm (6.0 in)
197583.1 mm (3.3 in)
1976122.2 mm (4.8 in)
1977162.2 mm (6.4 in)
1978135.2 mm (5.3 in)
1979152.2 mm (6.0 in)
1980129.4 mm (5.1 in)
1981146.9 mm (5.8 in)
1982131.2 mm (5.2 in)
1983149.9 mm (5.9 in)
1984150.4 mm (5.9 in)
1985143.3 mm (5.6 in)
1986196.1 mm (7.7 in)
1987101.9 mm (4.0 in)
1988154.7 mm (6.1 in)
1989109.3 mm (4.3 in)
1990143.4 mm (5.6 in)
1991110.8 mm (4.4 in)
1992130.9 mm (5.2 in)
1993153.3 mm (6.0 in)
1994178.7 mm (7.0 in)
1995118.4 mm (4.7 in)
199690.2 mm (3.6 in)
1997164.4 mm (6.5 in)
1998154.9 mm (6.1 in)
1999108.5 mm (4.3 in)
200087.7 mm (3.5 in)
2001165.9 mm (6.5 in)
2002106.2 mm (4.2 in)
2003158.1 mm (6.2 in)
2004166.0 mm (6.5 in)
2005183.9 mm (7.2 in)
200696.8 mm (3.8 in)
200734.8 mm (1.4 in)
2008170.6 mm (6.7 in)
200987.8 mm (3.5 in)
2010137.7 mm (5.4 in)
2011139.8 mm (5.5 in)
2012123.2 mm (4.9 in)

Longest dry spell (CDD)

Longest dry spell (CDD) at Palos Altos by year The longest dry spell of the year at Palos Altos, 1962 to 2012. The record is 168 days in 2005, marked on the chart; the median year is 107 days. 05010015020019701980199020002010Record: 168 days in 2005
The longest dry spell of the year at Palos Altos, 1962 to 2012. The record is 168 days in 2005, marked on the chart; the median year is 107 days.
Longest dry spell (CDD) at Palos Altos by year
YearLongest dry spell (CDD)
196243 days
1963124 days
196498 days
196571 days
196682 days
1967124 days
196864 days
1969144 days
1970148 days
1971144 days
1972144 days
1973119 days
1974107 days
1975108 days
197699 days
197758 days
197865 days
1979105 days
1980129 days
198156 days
198276 days
198372 days
1984119 days
1985123 days
1986118 days
1987109 days
198897 days
1989109 days
199050 days
1991126 days
1992100 days
1993142 days
199490 days
199564 days
1996136 days
199777 days
1998156 days
1999108 days
200084 days
200164 days
200296 days
200374 days
200477 days
2005168 days
2006120 days
2007121 days
2008139 days
2009116 days
2010109 days
2011104 days
201273 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Rainfall Return Levels

46 years, 1963 to 2012

A day with at least 67.0 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 109.0 mm (4.3 in) of rain is expected about once in 100 years.

Rainfall return levels at Palos Altos: the daily rain expected about once in a given number of years
Expected about once inA day with at leastNote
2 years67.0 mm (2.6 in)
5 years81.2 mm (3.2 in)
10 years89.2 mm (3.5 in)
25 years98.1 mm (3.9 in)
50 years103.9 mm (4.1 in)Longer than the 46 years of record
100 years109.0 mm (4.3 in)Longer than the 46 years of record

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 46 years of values from 1963 to 2012.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 101.9 mm (4.0 in) in 1994; 95.8 mm (3.8 in) in 1966; 93.0 mm (3.7 in) in 1977.

Download the Data

  • Data for Palos Altos standing records by year: CSV or JSON. Field meanings are on the data page.
  • Data for Palos Altos 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). Records are computed by this site and are not official.

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