Atotonilco Weather Records (MXN00010001)

Record envelope, standing records and threshold days for Atotonilco (MXN00010001), Mexico, with 39 years of record.

Key Facts for Atotonilco

Atotonilco (MXN00010001) is a weather station in Mexico at 24.63 latitude and -103.68 longitude, 1,950 m (6,397 ft) above sea level.
The station reports from 1969 to 2007, 39 years of record.
1,464 records set at Atotonilco still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Atotonilco tied a daily record low minimum temperature of -2.2 C (28.0 F) on 27 November 2007.

About the Station

Location: Mexico, 24.63 latitude, -103.68 longitude.
Elevation: 1,950 m (6,397 ft).
Period of record: 1969 to 2007, 39 years.
Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Atotonilco. 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 Atotonilco, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	32.2 C (90.0 F)	-9.4 C (15.1 F)	n/a	n/a
Feb	35.6 C (96.1 F)	-7.2 C (19.0 F)	n/a	n/a
Mar	36.7 C (98.1 F)	-5.0 C (23.0 F)	n/a	n/a
Apr	38.9 C (102.0 F)	-1.1 C (30.0 F)	n/a	n/a
May	40.0 C (104.0 F)	0.6 C (33.1 F)	n/a	n/a
Jun	40.6 C (105.1 F)	5.6 C (42.1 F)	n/a	n/a
Jul	36.7 C (98.1 F)	6.7 C (44.1 F)	n/a	n/a
Aug	37.2 C (99.0 F)	6.7 C (44.1 F)	n/a	n/a
Sep	37.8 C (100.0 F)	1.7 C (35.1 F)	n/a	n/a
Oct	37.2 C (99.0 F)	-4.4 C (24.1 F)	n/a	n/a
Nov	37.2 C (99.0 F)	-6.1 C (21.0 F)	n/a	n/a
Dec	33.9 C (93.0 F)	-11.1 C (12.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Atotonilco still stand. 1982 holds the most, with 160.

Standing records at Atotonilco by the year they were set
Year set	Standing records
1969	4
1970	12
1971	35
1972	42
1973	30
1974	24
1975	15
1976	38
1977	37
1978	21
1979	47
1980	102
1981	127
1982	160
1983	83
1984	64
1985	96
1986	5
1991	29
1992	22
1993	35
1994	18
1995	23
1996	29
1997	69
1998	26
1999	11
2000	23
2001	23
2002	40
2003	26
2004	38
2005	45
2006	32
2007	33

Wettest Day of Each Month

May: 74.9 mm (2.9 in)

The wettest day on record for each calendar month at Atotonilco. The most was 74.9 mm (2.9 in) on 27 May 1983.

Record daily precipitation for each month at Atotonilco
Month	Record daily precipitation (mm)	Date
Jan	26.9 mm (1.1 in)	13 January 1985
Feb	20.3 mm (0.8 in)	1 February 1997
Mar	24.9 mm (1.0 in)	30 March 2004
Apr	12.7 mm (0.5 in)	29 April 1982
May	74.9 mm (2.9 in)	27 May 1983
Jun	50.8 mm (2.0 in)	26 June 1993
Jul	46.0 mm (1.8 in)	21 July 1991
Aug	64.8 mm (2.6 in)	20 August 1996
Sep	71.9 mm (2.8 in)	1 September 2004
Oct	67.8 mm (2.7 in)	1 October 1970
Nov	24.9 mm (1.0 in)	25 November 1982
Dec	24.9 mm (1.0 in)	18 December 1975

Period of Record Coverage

1969 to 2007

35 years of record at Atotonilco, 1969 to 2007. 7 years have data for under 90 percent of days and are left out of rankings: 1969, 1970, 1973, 1986, 1991, 1992, 1996.

Days with data per year at Atotonilco
Year	Days with data	Share of year	Complete
1969	131	36%	No
1970	121	33%	No
1971	364	100%	Yes
1972	366	100%	Yes
1973	304	83%	No
1974	364	100%	Yes
1975	365	100%	Yes
1976	366	100%	Yes
1977	365	100%	Yes
1978	365	100%	Yes
1979	365	100%	Yes
1980	365	100%	Yes
1981	364	100%	Yes
1982	360	99%	Yes
1983	364	100%	Yes
1984	366	100%	Yes
1985	365	100%	Yes
1986	59	16%	No
1991	213	58%	No
1992	214	58%	No
1993	365	100%	Yes
1994	364	100%	Yes
1995	365	100%	Yes
1996	305	83%	No
1997	364	100%	Yes
1998	361	99%	Yes
1999	365	100%	Yes
2000	366	100%	Yes
2001	365	100%	Yes
2002	365	100%	Yes
2003	365	100%	Yes
2004	366	100%	Yes
2005	365	100%	Yes
2006	365	100%	Yes
2007	365	100%	Yes

Latest Records

Latest records at Atotonilco
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
27 November 2007	Atotonilco, MX	daily low min (Tie)	-2.2 C (28.0 F)	tie	13 years	1 of 100 (Routine)
7 November 2007	Atotonilco, MX	daily low max	16.7 C (62.1 F)	1.1 C (2.0 F)	30 years	14 of 100 (Routine)
6 November 2007	Atotonilco, MX	daily low max	16.7 C (62.1 F)	1.1 C (2.0 F)	4 years	6 of 100 (Routine)
1 November 2007	Atotonilco, MX	daily low min (Tie)	0.6 C (33.1 F)	tie	30 years	3 of 100 (Routine)
31 October 2007	Atotonilco, MX	daily low min (Tie)	3.9 C (39.0 F)	tie	5 years	1 of 100 (Routine)
30 October 2007	Atotonilco, MX	daily low min	-2.2 C (28.0 F)	3.9 C (7.0 F)	36 years	25 of 100 (Routine)
29 October 2007	Atotonilco, MX	daily low min	-2.2 C (28.0 F)	2.2 C (4.0 F)	0 years	9 of 100 (Routine)
27 October 2007	Atotonilco, MX	daily low min	0.0 C (32.0 F)	1.7 C (3.1 F)	8 years	9 of 100 (Routine)
26 October 2007	Atotonilco, MX	monthly low min (Tie)	-4.4 C (24.1 F)	tie	0 years	3 of 100 (Routine)
26 October 2007	Atotonilco, MX	daily low max (Tie)	15.0 C (59.0 F)	tie	4 years	1 of 100 (Routine)
25 October 2007	Atotonilco, MX	daily low min	-2.2 C (28.0 F)	1.1 C (2.0 F)	8 years	8 of 100 (Routine)
25 October 2007	Atotonilco, MX	daily low max (Tie)	15.0 C (59.0 F)	tie	4 years	1 of 100 (Routine)
24 October 2007	Atotonilco, MX	monthly low min (Tie)	-4.4 C (24.1 F)	tie	0 years	3 of 100 (Routine)
24 October 2007	Atotonilco, MX	daily low max (Tie)	15.6 C (60.1 F)	tie	1 year	0 of 100 (Routine)
23 October 2007	Atotonilco, MX	monthly low min	-4.4 C (24.1 F)	2.2 C (4.0 F)	10 years	22 of 100 (Routine)
23 October 2007	Atotonilco, MX	daily low max	13.9 C (57.0 F)	2.8 C (5.0 F)	0 years	9 of 100 (Routine)
22 October 2007	Atotonilco, MX	daily low max	16.7 C (62.1 F)	3.3 C (5.9 F)	30 years	19 of 100 (Routine)
15 September 2007	Atotonilco, MX	daily low max (Tie)	20.0 C (68.0 F)	tie	28 years	2 of 100 (Routine)
14 September 2007	Atotonilco, MX	daily low max	20.6 C (69.1 F)	1.1 C (2.0 F)	9 years	7 of 100 (Routine)
13 September 2007	Atotonilco, MX	daily low min (Tie)	7.8 C (46.0 F)	tie	14 years	1 of 100 (Routine)

Climate Trend

28 complete years, 1971 to 2007

One stripe for each of 28 complete years at Atotonilco, 1971 to 2007. Blue stripes are years cooler than the station's own mean of 16.9 C (62.4 F); red stripes are warmer. The coolest year was 2004, at 14.3 C (57.7 F), and the warmest was 1981, at 21.3 C (70.4 F). The strongest colour marks a difference of 4.5 C (8.1 F).

Annual mean temperature at Atotonilco as warming stripes, 1971 to 2007
Year	Annual mean temperature	Difference from the station mean
1971	17.5 C	+0.55 C
1972	18.1 C	+1.16 C
1974	16.5 C	-0.45 C
1975	16.5 C	-0.42 C
1976	15.6 C	-1.30 C
1977	17.4 C	+0.52 C
1978	17.6 C	+0.65 C
1979	18.2 C	+1.30 C
1980	19.7 C	+2.83 C
1981	21.3 C	+4.41 C
1982	20.9 C	+3.97 C
1983	19.9 C	+3.02 C
1984	20.2 C	+3.29 C
1985	20.3 C	+3.44 C
1993	15.4 C	-1.53 C
1994	16.0 C	-0.86 C
1995	15.4 C	-1.51 C
1997	14.4 C	-2.46 C
1998	15.9 C	-1.05 C
1999	15.5 C	-1.41 C
2000	15.9 C	-0.97 C
2001	15.7 C	-1.25 C
2002	15.4 C	-1.52 C
2003	14.8 C	-2.09 C
2004	14.3 C	-2.60 C
2005	14.9 C	-1.99 C
2006	15.0 C	-1.95 C
2007	15.1 C	-1.77 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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

1969 to 2007

Yearly extremes at Atotonilco: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	40.6 C (105.1 F)	1982	33.9 C (93.0 F)	35
Coldest night (TNn)	-11.1 C (12.0 F)	2004	-5.0 C (23.0 F)	35
Wettest day (Rx1day)	74.9 mm (2.9 in)	1983	39.9 mm (1.6 in)	35
Wettest five days (Rx5day)	119.6 mm (4.7 in)	1983	76.6 mm (3.0 in)	35
Longest dry spell (CDD)	170 days	1977	94 days	35

Hottest day (TXx)

The hottest day of the year at Atotonilco, 1969 to 2007. The record is 40.6 C (105.1 F) in 1982, marked on the chart; the median year is 33.9 C (93.0 F).

Hottest day (TXx) at Atotonilco by year
Year	Hottest day (TXx)
1969	35.6 C (96.1 F)
1970	30.0 C (86.0 F)
1971	35.6 C (96.1 F)
1972	37.8 C (100.0 F)
1973	33.9 C (93.0 F)
1974	33.9 C (93.0 F)
1975	33.9 C (93.0 F)
1976	32.8 C (91.0 F)
1977	33.9 C (93.0 F)
1978	35.6 C (96.1 F)
1979	35.0 C (95.0 F)
1980	37.8 C (100.0 F)
1981	38.9 C (102.0 F)
1982	40.6 C (105.1 F)
1983	40.0 C (104.0 F)
1984	40.0 C (104.0 F)
1985	40.0 C (104.0 F)
1986	29.4 C (84.9 F)
1991	35.6 C (96.1 F)
1992	35.0 C (95.0 F)
1993	32.8 C (91.0 F)
1994	33.9 C (93.0 F)
1995	31.7 C (89.1 F)
1996	31.7 C (89.1 F)
1997	31.7 C (89.1 F)
1998	33.9 C (93.0 F)
1999	33.9 C (93.0 F)
2000	32.8 C (91.0 F)
2001	31.7 C (89.1 F)
2002	32.8 C (91.0 F)
2003	33.9 C (93.0 F)
2004	33.9 C (93.0 F)
2005	35.0 C (95.0 F)
2006	31.7 C (89.1 F)
2007	33.9 C (93.0 F)

Coldest night (TNn)

The coldest night of the year at Atotonilco, 1969 to 2007. The record is -11.1 C (12.0 F) in 2004, marked on the chart; the median year is -5.0 C (23.0 F).

Coldest night (TNn) at Atotonilco by year
Year	Coldest night (TNn)
1969	0.0 C (32.0 F)
1970	-5.0 C (23.0 F)
1971	-5.0 C (23.0 F)
1972	-2.2 C (28.0 F)
1973	-2.2 C (28.0 F)
1974	-5.0 C (23.0 F)
1975	-5.0 C (23.0 F)
1976	-6.7 C (19.9 F)
1977	-2.2 C (28.0 F)
1978	-1.7 C (28.9 F)
1979	-4.4 C (24.1 F)
1980	-6.1 C (21.0 F)
1981	-3.3 C (26.1 F)
1982	-3.3 C (26.1 F)
1983	-6.1 C (21.0 F)
1984	-4.4 C (24.1 F)
1985	-8.3 C (17.1 F)
1986	-2.2 C (28.0 F)
1991	0.6 C (33.1 F)
1992	0.0 C (32.0 F)
1993	-3.3 C (26.1 F)
1994	0.0 C (32.0 F)
1995	-3.3 C (26.1 F)
1996	-8.3 C (17.1 F)
1997	-10.0 C (14.0 F)
1998	-9.4 C (15.1 F)
1999	-8.3 C (17.1 F)
2000	-5.0 C (23.0 F)
2001	-8.3 C (17.1 F)
2002	-7.2 C (19.0 F)
2003	-8.3 C (17.1 F)
2004	-11.1 C (12.0 F)
2005	-5.0 C (23.0 F)
2006	-8.3 C (17.1 F)
2007	-5.0 C (23.0 F)

Wettest day (Rx1day)

The wettest day of the year at Atotonilco, 1969 to 2007. The record is 74.9 mm (2.9 in) in 1983, marked on the chart; the median year is 39.9 mm (1.6 in).

Wettest day (Rx1day) at Atotonilco by year
Year	Wettest day (Rx1day)
1969	67.8 mm (2.7 in)
1970	67.8 mm (2.7 in)
1971	43.9 mm (1.7 in)
1972	47.0 mm (1.9 in)
1973	35.8 mm (1.4 in)
1974	31.5 mm (1.2 in)
1975	24.9 mm (1.0 in)
1976	35.3 mm (1.4 in)
1977	5.1 mm (0.20 in)
1978	39.9 mm (1.6 in)
1979	11.2 mm (0.4 in)
1980	8.9 mm (0.35 in)
1981	30.0 mm (1.2 in)
1982	31.5 mm (1.2 in)
1983	74.9 mm (2.9 in)
1984	32.8 mm (1.3 in)
1985	41.1 mm (1.6 in)
1986	3.8 mm (0.15 in)
1991	46.0 mm (1.8 in)
1992	42.9 mm (1.7 in)
1993	56.9 mm (2.2 in)
1994	35.8 mm (1.4 in)
1995	45.0 mm (1.8 in)
1996	64.8 mm (2.6 in)
1997	27.9 mm (1.1 in)
1998	37.3 mm (1.5 in)
1999	32.3 mm (1.3 in)
2000	42.9 mm (1.7 in)
2001	24.9 mm (1.0 in)
2002	64.8 mm (2.6 in)
2003	59.9 mm (2.4 in)
2004	71.9 mm (2.8 in)
2005	52.3 mm (2.1 in)
2006	39.9 mm (1.6 in)
2007	30.0 mm (1.2 in)

Wettest five days (Rx5day)

The wettest five days of the year at Atotonilco, 1969 to 2007. The record is 119.6 mm (4.7 in) in 1983, marked on the chart; the median year is 76.6 mm (3.0 in).

Wettest five days (Rx5day) at Atotonilco by year
Year	Wettest five days (Rx5day)
1969	68.1 mm (2.7 in)
1970	82.6 mm (3.3 in)
1971	99.5 mm (3.9 in)
1972	104.1 mm (4.1 in)
1973	111.0 mm (4.4 in)
1974	54.4 mm (2.1 in)
1975	63.1 mm (2.5 in)
1976	77.8 mm (3.1 in)
1977	7.4 mm (0.29 in)
1978	89.9 mm (3.5 in)
1979	25.7 mm (1.0 in)
1980	15.3 mm (0.6 in)
1981	73.5 mm (2.9 in)
1982	44.3 mm (1.7 in)
1983	119.6 mm (4.7 in)
1984	79.5 mm (3.1 in)
1985	109.4 mm (4.3 in)
1986	3.8 mm (0.15 in)
1991	82.5 mm (3.2 in)
1992	60.7 mm (2.4 in)
1993	93.8 mm (3.7 in)
1994	55.1 mm (2.2 in)
1995	69.9 mm (2.8 in)
1996	107.5 mm (4.2 in)
1997	47.2 mm (1.9 in)
1998	76.6 mm (3.0 in)
1999	76.5 mm (3.0 in)
2000	105.2 mm (4.1 in)
2001	54.9 mm (2.2 in)
2002	104.5 mm (4.1 in)
2003	93.7 mm (3.7 in)
2004	113.3 mm (4.5 in)
2005	54.6 mm (2.1 in)
2006	97.3 mm (3.8 in)
2007	64.5 mm (2.5 in)

Longest dry spell (CDD)

The longest dry spell of the year at Atotonilco, 1969 to 2007. The record is 170 days in 1977, marked on the chart; the median year is 94 days.

Longest dry spell (CDD) at Atotonilco by year
Year	Longest dry spell (CDD)
1969	62 days
1970	91 days
1971	81 days
1972	76 days
1973	71 days
1974	149 days
1975	145 days
1976	94 days
1977	170 days
1978	136 days
1979	98 days
1980	134 days
1981	84 days
1982	111 days
1983	124 days
1984	104 days
1985	83 days
1986	32 days
1991	34 days
1992	50 days
1993	83 days
1994	56 days
1995	166 days
1996	118 days
1997	53 days
1998	156 days
1999	156 days
2000	117 days
2001	83 days
2002	49 days
2003	66 days
2004	74 days
2005	115 days
2006	134 days
2007	137 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

24 years with a frost

Across 24 years with a frost, the median last spring frost at Atotonilco falls on 28 February and the median first autumn frost on 18 November, which leaves a median of 258 days between them.

Frost dates and growing season at Atotonilco
Measure	Median, all years	Earliest period	Recent period (1971 to 2007)	Recent against earliest	Fitted trend
Last spring frost	28 February	n/a	28 February	n/a	n/a
First autumn frost	18 November	n/a	18 November	n/a	n/a
Growing days	258 days	n/a	258 days	n/a	n/a

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.

Download the Data

Data for Atotonilco standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Atotonilco 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 2025-12-31. Last revised 31 December 2025 (2025-12-31).