Chiconautla Weather Records (MXN00015022)
Record envelope, standing records and threshold days for Chiconautla (MXN00015022), Mexico, with 50 years of record.
Key Facts for Chiconautla
- Chiconautla (MXN00015022) is a weather station in Mexico at 19.65 latitude and -99.02 longitude, 2,340 m (7,677 ft) above sea level.
- The station reports from 1963 to 2012, 50 years of record.
- 1,464 records set at Chiconautla still stand.
- Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
- Chiconautla set a daily record high maximum temperature of 31.7 C (89.1 F) on 31 December 2012.
About the Station
- Location: Mexico, 19.65 latitude, -99.02 longitude.
- Elevation: 2,340 m (7,677 ft).
- Period of record: 1963 to 2012, 50 years.
- Eligible elements: tmax, tmin, prcp.
Daily Record Envelope and 2026
0 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 33.9 C (93.0 F) | -10.0 C (14.0 F) | n/a | n/a |
| Feb | 36.7 C (98.1 F) | -10.0 C (14.0 F) | n/a | n/a |
| Mar | 37.2 C (99.0 F) | -5.0 C (23.0 F) | n/a | n/a |
| Apr | 39.4 C (102.9 F) | -2.8 C (27.0 F) | n/a | n/a |
| May | 40.0 C (104.0 F) | 0.0 C (32.0 F) | n/a | n/a |
| Jun | 38.9 C (102.0 F) | 1.7 C (35.1 F) | n/a | n/a |
| Jul | 35.0 C (95.0 F) | 0.0 C (32.0 F) | n/a | n/a |
| Aug | 36.1 C (97.0 F) | 0.6 C (33.1 F) | n/a | n/a |
| Sep | 35.6 C (96.1 F) | -1.7 C (28.9 F) | n/a | n/a |
| Oct | 36.7 C (98.1 F) | -3.3 C (26.1 F) | n/a | n/a |
| Nov | 35.0 C (95.0 F) | -9.4 C (15.1 F) | n/a | n/a |
| Dec | 35.6 C (96.1 F) | -8.3 C (17.1 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1963 | 18 |
| 1964 | 30 |
| 1965 | 42 |
| 1966 | 46 |
| 1967 | 44 |
| 1968 | 44 |
| 1969 | 44 |
| 1970 | 33 |
| 1971 | 23 |
| 1972 | 22 |
| 1973 | 25 |
| 1974 | 30 |
| 1975 | 28 |
| 1976 | 35 |
| 1977 | 23 |
| 1978 | 21 |
| 1979 | 40 |
| 1980 | 13 |
| 1981 | 8 |
| 1982 | 12 |
| 1983 | 18 |
| 1984 | 13 |
| 1985 | 8 |
| 1986 | 8 |
| 1987 | 14 |
| 1988 | 15 |
| 1996 | 3 |
| 1997 | 2 |
| 1998 | 2 |
| 1999 | 6 |
| 2000 | 5 |
| 2001 | 1 |
| 2002 | 5 |
| 2003 | 5 |
| 2004 | 6 |
| 2005 | 9 |
| 2006 | 20 |
| 2007 | 119 |
| 2008 | 121 |
| 2009 | 54 |
| 2010 | 71 |
| 2011 | 95 |
| 2012 | 283 |
All-Time Record Progression
8 new records| Date | Kind | Detail |
|---|---|---|
| 2007-08-04 | Record high minimum temperature | Record high minimum temperature 17.8 C (64.0 F) |
| 2007-08-12 | Record high minimum temperature | Record high minimum temperature 18.9 C (66.0 F) |
| 2011-08-09 | Record high maximum temperature | Record high maximum temperature 36.1 C (97.0 F) |
| 2012-02-23 | Record high maximum temperature | Record high maximum temperature 36.7 C (98.1 F) |
| 2012-03-03 | Record high maximum temperature | Record high maximum temperature 37.2 C (99.0 F) |
| 2012-04-27 | Record high maximum temperature | Record high maximum temperature 38.3 C (100.9 F) |
| 2012-04-29 | Record high maximum temperature | Record high maximum temperature 39.4 C (102.9 F) |
| 2012-05-02 | Record high maximum temperature | Record high maximum temperature 40.0 C (104.0 F) |
Wettest Day of Each Month
Aug: 86.9 mm (3.4 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 39.9 mm (1.6 in) | 10 January 1967 |
| Feb | 43.9 mm (1.7 in) | 7 February 2012 |
| Mar | 59.9 mm (2.4 in) | 9 March 2012 |
| Apr | 38.1 mm (1.5 in) | 30 April 1981 |
| May | 65.8 mm (2.6 in) | 17 May 2012 |
| Jun | 64.8 mm (2.6 in) | 22 June 2011 |
| Jul | 62.5 mm (2.5 in) | 1 July 2011 |
| Aug | 86.9 mm (3.4 in) | 31 August 1988 |
| Sep | 79.8 mm (3.1 in) | 6 September 2002 |
| Oct | 65.5 mm (2.6 in) | 30 October 2009 |
| Nov | 20.3 mm (0.8 in) | 12 November 2006 |
| Dec | 25.7 mm (1.0 in) | 1 December 1976 |
Period of Record Coverage
1963 to 2012| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1963 | 230 | 63% | No |
| 1964 | 362 | 99% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 364 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 365 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 365 | 100% | Yes |
| 1978 | 365 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 364 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
| 1984 | 366 | 100% | Yes |
| 1985 | 334 | 92% | Yes |
| 1986 | 365 | 100% | Yes |
| 1987 | 363 | 99% | Yes |
| 1988 | 244 | 67% | No |
| 1996 | 201 | 55% | No |
| 1997 | 365 | 100% | Yes |
| 1998 | 365 | 100% | Yes |
| 1999 | 365 | 100% | Yes |
| 2000 | 334 | 91% | Yes |
| 2001 | 363 | 99% | Yes |
| 2002 | 365 | 100% | Yes |
| 2003 | 304 | 83% | No |
| 2004 | 360 | 98% | Yes |
| 2005 | 364 | 100% | Yes |
| 2006 | 364 | 100% | Yes |
| 2007 | 363 | 99% | Yes |
| 2008 | 347 | 95% | Yes |
| 2009 | 365 | 100% | Yes |
| 2010 | 243 | 67% | No |
| 2011 | 361 | 99% | Yes |
| 2012 | 362 | 99% | Yes |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 31 December 2012 | Chiconautla, MX | daily high max | 31.7 C (89.1 F) | 1.1 C (2.0 F) | 1 year | 8 of 100 (Routine) |
| 30 December 2012 | Chiconautla, MX | daily high max | 32.2 C (90.0 F) | 2.2 C (4.0 F) | 1 year | 12 of 100 (Routine) |
| 29 December 2012 | Chiconautla, MX | daily high max (Tie) | 31.1 C (88.0 F) | tie | 1 year | 1 of 100 (Routine) |
| 27 December 2012 | Chiconautla, MX | daily high max | 32.2 C (90.0 F) | 1.1 C (2.0 F) | 1 year | 8 of 100 (Routine) |
| 26 December 2012 | Chiconautla, MX | daily high max (Tie) | 31.7 C (89.1 F) | tie | 1 year | 1 of 100 (Routine) |
| 25 December 2012 | Chiconautla, MX | daily high max | 33.9 C (93.0 F) | 1.1 C (2.0 F) | 1 year | 8 of 100 (Routine) |
| 24 December 2012 | Chiconautla, MX | daily high max | 32.8 C (91.0 F) | 0.6 C (1.1 F) | 1 year | 7 of 100 (Routine) |
| 23 December 2012 | Chiconautla, MX | daily high max (Tie) | 32.8 C (91.0 F) | tie | 1 year | 1 of 100 (Routine) |
| 22 December 2012 | Chiconautla, MX | daily high max | 32.8 C (91.0 F) | 0.6 C (1.1 F) | 1 year | 7 of 100 (Routine) |
| 19 December 2012 | Chiconautla, MX | daily high max | 33.9 C (93.0 F) | 1.7 C (3.1 F) | 1 year | 10 of 100 (Routine) |
| 18 December 2012 | Chiconautla, MX | daily high max | 32.8 C (91.0 F) | 1.7 C (3.1 F) | 1 year | 10 of 100 (Routine) |
| 17 December 2012 | Chiconautla, MX | daily high max | 32.8 C (91.0 F) | 6.7 C (12.1 F) | 1 year | 28 of 100 (Routine) |
| 16 December 2012 | Chiconautla, MX | monthly high max | 35.6 C (96.1 F) | 0.6 C (1.1 F) | 0 years | 17 of 100 (Routine) |
| 15 December 2012 | Chiconautla, MX | daily high max (Tie) | 32.8 C (91.0 F) | tie | 1 year | 1 of 100 (Routine) |
| 14 December 2012 | Chiconautla, MX | daily high max | 34.4 C (93.9 F) | 0.5 C (0.9 F) | 1 year | 6 of 100 (Routine) |
| 11 December 2012 | Chiconautla, MX | daily high max (Tie) | 31.7 C (89.1 F) | tie | 1 year | 1 of 100 (Routine) |
| 10 December 2012 | Chiconautla, MX | daily high max | 32.8 C (91.0 F) | 2.8 C (5.0 F) | 1 year | 14 of 100 (Routine) |
| 9 December 2012 | Chiconautla, MX | monthly high max | 35.0 C (95.0 F) | 0.6 C (1.1 F) | 1 year | 17 of 100 (Routine) |
| 8 December 2012 | Chiconautla, MX | daily high max | 31.7 C (89.1 F) | 1.1 C (2.0 F) | 1 year | 8 of 100 (Routine) |
| 4 December 2012 | Chiconautla, MX | daily high max | 30.6 C (87.1 F) | 0.6 C (1.1 F) | 1 year | 7 of 100 (Routine) |
Climate Trend
35 complete years, 1964 to 2012| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1964 | 14.5 C | -0.52 C |
| 1965 | 14.0 C | -0.97 C |
| 1966 | 14.1 C | -0.92 C |
| 1967 | 14.0 C | -0.99 C |
| 1968 | 13.5 C | -1.48 C |
| 1969 | 14.4 C | -0.59 C |
| 1970 | 14.3 C | -0.69 C |
| 1971 | 14.2 C | -0.78 C |
| 1972 | 14.5 C | -0.48 C |
| 1973 | 14.6 C | -0.40 C |
| 1974 | 14.2 C | -0.74 C |
| 1975 | 14.6 C | -0.42 C |
| 1976 | 14.1 C | -0.84 C |
| 1977 | 14.4 C | -0.60 C |
| 1978 | 15.1 C | +0.10 C |
| 1979 | 14.6 C | -0.42 C |
| 1980 | 15.5 C | +0.48 C |
| 1981 | 15.1 C | +0.08 C |
| 1982 | 15.7 C | +0.74 C |
| 1983 | 15.2 C | +0.25 C |
| 1984 | 15.0 C | +0.01 C |
| 1986 | 14.6 C | -0.36 C |
| 1987 | 14.9 C | -0.11 C |
| 1997 | 15.3 C | +0.33 C |
| 1998 | 15.3 C | +0.34 C |
| 1999 | 14.5 C | -0.44 C |
| 2001 | 14.7 C | -0.27 C |
| 2002 | 15.1 C | +0.13 C |
| 2004 | 15.8 C | +0.81 C |
| 2005 | 13.8 C | -1.23 C |
| 2006 | 14.4 C | -0.58 C |
| 2007 | 16.1 C | +1.07 C |
| 2009 | 17.3 C | +2.34 C |
| 2011 | 17.5 C | +2.53 C |
| 2012 | 19.7 C | +4.76 C |
The annual mean temperature here has risen by 0.5 C (0.3 to 0.7) per decade over 1964 to 2012. In Fahrenheit: 0.9 F (0.5 to 1.3) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.5 C (0.3 to 0.7) per decade | 0.9 F (0.5 to 1.3) per decade | 1964 to 2012 | 35 | Rise |
| Mean daily maximum | 0.5 C (0.1 to 0.9) per decade | 0.9 F (0.2 to 1.6) per decade | 1964 to 2012 | 35 | Rise |
| Mean daily minimum | 0.5 C (0.2 to 0.8) per decade | 0.9 F (0.4 to 1.4) per decade | 1964 to 2012 | 35 | Rise |
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
1963 to 2012| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 40.0 C (104.0 F) | 2012 | 30.6 C (87.1 F) | 43 |
| Coldest night (TNn) | -10.0 C (14.0 F) | 1973 | -5.0 C (23.0 F) | 43 |
| Wettest day (Rx1day) | 86.9 mm (3.4 in) | 1988 | 41.9 mm (1.6 in) | 43 |
| Wettest five days (Rx5day) | 145.6 mm (5.7 in) | 2011 | 73.6 mm (2.9 in) | 43 |
| Longest dry spell (CDD) | 138 days | 1998 | 55 days | 43 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1963 | 30.6 C (87.1 F) |
| 1964 | 30.6 C (87.1 F) |
| 1965 | 30.0 C (86.0 F) |
| 1966 | 31.1 C (88.0 F) |
| 1967 | 30.6 C (87.1 F) |
| 1968 | 29.4 C (84.9 F) |
| 1969 | 32.2 C (90.0 F) |
| 1970 | 33.9 C (93.0 F) |
| 1971 | 31.1 C (88.0 F) |
| 1972 | 30.0 C (86.0 F) |
| 1973 | 32.2 C (90.0 F) |
| 1974 | 32.2 C (90.0 F) |
| 1975 | 31.1 C (88.0 F) |
| 1976 | 28.9 C (84.0 F) |
| 1977 | 30.6 C (87.1 F) |
| 1978 | 31.7 C (89.1 F) |
| 1979 | 31.7 C (89.1 F) |
| 1980 | 31.7 C (89.1 F) |
| 1981 | 31.7 C (89.1 F) |
| 1982 | 32.8 C (91.0 F) |
| 1983 | 35.0 C (95.0 F) |
| 1984 | 32.8 C (91.0 F) |
| 1985 | 31.1 C (88.0 F) |
| 1986 | 31.1 C (88.0 F) |
| 1987 | 30.0 C (86.0 F) |
| 1988 | 31.1 C (88.0 F) |
| 1996 | 30.0 C (86.0 F) |
| 1997 | 27.8 C (82.0 F) |
| 1998 | 30.0 C (86.0 F) |
| 1999 | 30.0 C (86.0 F) |
| 2000 | 27.8 C (82.0 F) |
| 2001 | 30.0 C (86.0 F) |
| 2002 | 29.4 C (84.9 F) |
| 2003 | 29.4 C (84.9 F) |
| 2004 | 30.6 C (87.1 F) |
| 2005 | 30.0 C (86.0 F) |
| 2006 | 28.9 C (84.0 F) |
| 2007 | 26.7 C (80.1 F) |
| 2008 | 30.0 C (86.0 F) |
| 2009 | 26.1 C (79.0 F) |
| 2010 | 32.8 C (91.0 F) |
| 2011 | 36.1 C (97.0 F) |
| 2012 | 40.0 C (104.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1963 | -8.3 C (17.1 F) |
| 1964 | -4.4 C (24.1 F) |
| 1965 | -8.9 C (16.0 F) |
| 1966 | -9.4 C (15.1 F) |
| 1967 | -8.3 C (17.1 F) |
| 1968 | -7.2 C (19.0 F) |
| 1969 | -5.6 C (21.9 F) |
| 1970 | -6.7 C (19.9 F) |
| 1971 | -7.2 C (19.0 F) |
| 1972 | -8.3 C (17.1 F) |
| 1973 | -10.0 C (14.0 F) |
| 1974 | -8.3 C (17.1 F) |
| 1975 | -8.3 C (17.1 F) |
| 1976 | -10.0 C (14.0 F) |
| 1977 | -5.0 C (23.0 F) |
| 1978 | -5.0 C (23.0 F) |
| 1979 | -3.3 C (26.1 F) |
| 1980 | -6.1 C (21.0 F) |
| 1981 | -6.1 C (21.0 F) |
| 1982 | -3.3 C (26.1 F) |
| 1983 | -4.4 C (24.1 F) |
| 1984 | -3.9 C (25.0 F) |
| 1985 | -3.9 C (25.0 F) |
| 1986 | -7.2 C (19.0 F) |
| 1987 | -5.6 C (21.9 F) |
| 1988 | -8.3 C (17.1 F) |
| 1996 | -5.0 C (23.0 F) |
| 1997 | -4.4 C (24.1 F) |
| 1998 | -5.0 C (23.0 F) |
| 1999 | -6.1 C (21.0 F) |
| 2000 | -3.3 C (26.1 F) |
| 2001 | -1.7 C (28.9 F) |
| 2002 | -2.2 C (28.0 F) |
| 2003 | -1.7 C (28.9 F) |
| 2004 | 0.6 C (33.1 F) |
| 2005 | -1.7 C (28.9 F) |
| 2006 | -2.2 C (28.0 F) |
| 2007 | -3.3 C (26.1 F) |
| 2008 | 3.9 C (39.0 F) |
| 2009 | 6.7 C (44.1 F) |
| 2010 | -1.1 C (30.0 F) |
| 2011 | 0.0 C (32.0 F) |
| 2012 | 0.0 C (32.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1963 | 37.1 mm (1.5 in) |
| 1964 | 31.8 mm (1.3 in) |
| 1965 | 34.3 mm (1.4 in) |
| 1966 | 48.8 mm (1.9 in) |
| 1967 | 50.3 mm (2.0 in) |
| 1968 | 39.9 mm (1.6 in) |
| 1969 | 43.9 mm (1.7 in) |
| 1970 | 27.7 mm (1.1 in) |
| 1971 | 44.5 mm (1.8 in) |
| 1972 | 39.1 mm (1.5 in) |
| 1973 | 33.0 mm (1.3 in) |
| 1974 | 26.7 mm (1.1 in) |
| 1975 | 26.7 mm (1.1 in) |
| 1976 | 52.6 mm (2.1 in) |
| 1977 | 39.4 mm (1.6 in) |
| 1978 | 28.7 mm (1.1 in) |
| 1979 | 43.9 mm (1.7 in) |
| 1980 | 34.8 mm (1.4 in) |
| 1981 | 52.6 mm (2.1 in) |
| 1982 | 44.7 mm (1.8 in) |
| 1983 | 39.9 mm (1.6 in) |
| 1984 | 45.7 mm (1.8 in) |
| 1985 | 24.9 mm (1.0 in) |
| 1986 | 30.0 mm (1.2 in) |
| 1987 | 49.8 mm (2.0 in) |
| 1988 | 86.9 mm (3.4 in) |
| 1996 | 35.3 mm (1.4 in) |
| 1997 | 22.4 mm (0.9 in) |
| 1998 | 32.3 mm (1.3 in) |
| 1999 | 45.0 mm (1.8 in) |
| 2000 | 58.9 mm (2.3 in) |
| 2001 | 56.9 mm (2.2 in) |
| 2002 | 79.8 mm (3.1 in) |
| 2003 | 43.2 mm (1.7 in) |
| 2004 | 47.5 mm (1.9 in) |
| 2005 | 41.9 mm (1.6 in) |
| 2006 | 38.9 mm (1.5 in) |
| 2007 | 39.9 mm (1.6 in) |
| 2008 | 46.5 mm (1.8 in) |
| 2009 | 65.5 mm (2.6 in) |
| 2010 | 39.9 mm (1.6 in) |
| 2011 | 64.8 mm (2.6 in) |
| 2012 | 65.8 mm (2.6 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1963 | 59.0 mm (2.3 in) |
| 1964 | 83.3 mm (3.3 in) |
| 1965 | 76.8 mm (3.0 in) |
| 1966 | 96.6 mm (3.8 in) |
| 1967 | 61.8 mm (2.4 in) |
| 1968 | 87.4 mm (3.4 in) |
| 1969 | 85.6 mm (3.4 in) |
| 1970 | 53.9 mm (2.1 in) |
| 1971 | 114.4 mm (4.5 in) |
| 1972 | 55.4 mm (2.2 in) |
| 1973 | 71.2 mm (2.8 in) |
| 1974 | 63.1 mm (2.5 in) |
| 1975 | 73.6 mm (2.9 in) |
| 1976 | 88.2 mm (3.5 in) |
| 1977 | 80.4 mm (3.2 in) |
| 1978 | 59.7 mm (2.4 in) |
| 1979 | 71.9 mm (2.8 in) |
| 1980 | 69.6 mm (2.7 in) |
| 1981 | 74.7 mm (2.9 in) |
| 1982 | 66.9 mm (2.6 in) |
| 1983 | 71.9 mm (2.8 in) |
| 1984 | 107.9 mm (4.2 in) |
| 1985 | 40.9 mm (1.6 in) |
| 1986 | 57.9 mm (2.3 in) |
| 1987 | 66.9 mm (2.6 in) |
| 1988 | 96.1 mm (3.8 in) |
| 1996 | 48.8 mm (1.9 in) |
| 1997 | 53.1 mm (2.1 in) |
| 1998 | 63.4 mm (2.5 in) |
| 1999 | 74.2 mm (2.9 in) |
| 2000 | 108.8 mm (4.3 in) |
| 2001 | 95.8 mm (3.8 in) |
| 2002 | 112.3 mm (4.4 in) |
| 2003 | 67.4 mm (2.7 in) |
| 2004 | 75.2 mm (3.0 in) |
| 2005 | 60.2 mm (2.4 in) |
| 2006 | 89.0 mm (3.5 in) |
| 2007 | 66.0 mm (2.6 in) |
| 2008 | 78.2 mm (3.1 in) |
| 2009 | 73.5 mm (2.9 in) |
| 2010 | 91.4 mm (3.6 in) |
| 2011 | 145.6 mm (5.7 in) |
| 2012 | 137.7 mm (5.4 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1963 | 27 days |
| 1964 | 46 days |
| 1965 | 51 days |
| 1966 | 52 days |
| 1967 | 51 days |
| 1968 | 43 days |
| 1969 | 48 days |
| 1970 | 79 days |
| 1971 | 76 days |
| 1972 | 57 days |
| 1973 | 57 days |
| 1974 | 39 days |
| 1975 | 82 days |
| 1976 | 39 days |
| 1977 | 62 days |
| 1978 | 43 days |
| 1979 | 41 days |
| 1980 | 35 days |
| 1981 | 58 days |
| 1982 | 61 days |
| 1983 | 55 days |
| 1984 | 41 days |
| 1985 | 49 days |
| 1986 | 101 days |
| 1987 | 63 days |
| 1988 | 39 days |
| 1996 | 36 days |
| 1997 | 81 days |
| 1998 | 138 days |
| 1999 | 82 days |
| 2000 | 77 days |
| 2001 | 67 days |
| 2002 | 45 days |
| 2003 | 122 days |
| 2004 | 59 days |
| 2005 | 57 days |
| 2006 | 48 days |
| 2007 | 71 days |
| 2008 | 46 days |
| 2009 | 70 days |
| 2010 | 48 days |
| 2011 | 55 days |
| 2012 | 56 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.
Frost Dates and Growing Season
29 years with a frostAcross 29 years with a frost, the median last spring frost at Chiconautla falls on 22 March and the median first autumn frost on 2 November, which leaves a median of 216 days between them.
Fitted over all years, the growing season changes by +9.4 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1964 to 2012) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 22 March | n/a | 22 March | n/a | -8.6 days per decade |
| First autumn frost | 2 November | n/a | 2 November | n/a | +0.9 days per decade |
| Growing days | 216 days | n/a | 216 days | n/a | +9.4 days per decade |
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
39 years, 1964 to 2012A day with at least 41.6 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 79.8 mm (3.1 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 41.6 mm (1.6 in) | |
| 5 years | 53.2 mm (2.1 in) | |
| 10 years | 60.2 mm (2.4 in) | |
| 25 years | 68.6 mm (2.7 in) | |
| 50 years | 74.4 mm (2.9 in) | Longer than the 39 years of record |
| 100 years | 79.8 mm (3.1 in) | Longer than the 39 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, 39 years of values from 1964 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: 79.8 mm (3.1 in) in 2002; 65.8 mm (2.6 in) in 2012; 65.5 mm (2.6 in) in 2009.
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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).