Delta Weather Records (MXN00002011)

Record envelope, standing records and threshold days for Delta (MXN00002011), Mexico, with 65 years of record.

Key Facts for Delta

Delta (MXN00002011) is a weather station in Mexico at 32.35 latitude and -115.18 longitude, 12 m (39 ft) above sea level.
The station reports from 1948 to 2012, 65 years of record.
1,464 records set at Delta still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Delta tied a daily record high maximum temperature of 45.0 C (113.0 F) on 2 October 2012.

About the Station

Location: Mexico, 32.35 latitude, -115.18 longitude.
Elevation: 12 m (39 ft).
Period of record: 1948 to 2012, 65 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 Delta. 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 Delta, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	38.9 C (102.0 F)	-6.1 C (21.0 F)	n/a	n/a
Feb	41.7 C (107.1 F)	-3.9 C (25.0 F)	n/a	n/a
Mar	43.9 C (111.0 F)	-2.2 C (28.0 F)	n/a	n/a
Apr	45.6 C (114.1 F)	0.0 C (32.0 F)	n/a	n/a
May	48.9 C (120.0 F)	0.0 C (32.0 F)	n/a	n/a
Jun	55.6 C (132.1 F)	2.8 C (37.0 F)	n/a	n/a
Jul	56.7 C (134.1 F)	6.7 C (44.1 F)	n/a	n/a
Aug	56.7 C (134.1 F)	10.0 C (50.0 F)	n/a	n/a
Sep	55.0 C (131.0 F)	5.6 C (42.1 F)	n/a	n/a
Oct	47.8 C (118.0 F)	0.6 C (33.1 F)	n/a	n/a
Nov	47.8 C (118.0 F)	-3.3 C (26.1 F)	n/a	n/a
Dec	40.0 C (104.0 F)	-5.0 C (23.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Delta still stand. 1967 holds the most, with 91.

Standing records at Delta by the year they were set
Year set	Standing records
1948	34
1949	35
1950	58
1951	45
1952	33
1953	75
1954	8
1955	24
1956	31
1957	40
1958	76
1959	16
1960	37
1961	11
1962	17
1963	13
1964	19
1965	12
1966	74
1967	91
1968	11
1969	16
1970	17
1971	30
1972	25
1973	9
1974	4
1975	11
1976	13
1977	15
1978	13
1979	18
1980	22
1981	15
1982	17
1983	28
1984	28
1985	19
1986	16
1987	14
1988	8
1989	23
1990	16
1991	4
1992	39
1993	40
1994	83
1995	9
1996	18
1997	8
1998	7
1999	4
2000	11
2001	10
2002	3
2003	5
2004	11
2005	1
2006	14
2007	11
2008	8
2009	4
2010	20
2011	14
2012	3

All-Time Record Progression

6 new records

6 all-time records were set at Delta between 22 August 1982 and 24 August 2010. Each dot is a new record.

When Delta set new all-time records
Date	Kind	Detail
1982-08-22	Record high minimum temperature	Record high minimum temperature 32.2 C (90.0 F)
1996-07-31	Record high minimum temperature	Record high minimum temperature 32.8 C (91.0 F)
1997-12-26	Record low minimum temperature	Record low minimum temperature -5.0 C (23.0 F)
1998-09-01	Record high minimum temperature	Record high minimum temperature 33.9 C (93.0 F)
2007-01-14	Record low minimum temperature	Record low minimum temperature -6.1 C (21.0 F)
2010-08-24	Record high minimum temperature	Record high minimum temperature 35.0 C (95.0 F)

Wettest Day of Each Month

Oct: 63.0 mm (2.5 in)

The wettest day on record for each calendar month at Delta. The most was 63.0 mm (2.5 in) on 6 October 1972.

Record daily precipitation for each month at Delta
Month	Record daily precipitation (mm)	Date
Jan	31.8 mm (1.3 in)	20 January 2010
Feb	40.4 mm (1.6 in)	2 February 1983
Mar	24.9 mm (1.0 in)	27 March 1992
Apr	11.9 mm (0.5 in)	27 April 1952
May	11.9 mm (0.5 in)	23 May 1977
Jun	5.8 mm (0.23 in)	25 June 1955
Jul	50.8 mm (2.0 in)	30 July 2012
Aug	45.0 mm (1.8 in)	11 August 1979
Sep	37.8 mm (1.5 in)	11 September 2008
Oct	63.0 mm (2.5 in)	6 October 1972
Nov	21.8 mm (0.9 in)	30 November 2007
Dec	43.9 mm (1.7 in)	8 December 1982

Period of Record Coverage

1948 to 2012

65 years of record at Delta, 1948 to 2012. 14 years have data for under 90 percent of days and are left out of rankings: 1948, 1956, 1963, 1984, 1989, 1990, 1991, 1992 and others.

Days with data per year at Delta
Year	Days with data	Share of year	Complete
1948	178	49%	No
1949	365	100%	Yes
1950	364	100%	Yes
1951	353	97%	Yes
1952	365	100%	Yes
1953	360	99%	Yes
1954	364	100%	Yes
1955	364	100%	Yes
1956	324	89%	No
1957	359	98%	Yes
1958	361	99%	Yes
1959	361	99%	Yes
1960	365	100%	Yes
1961	363	99%	Yes
1962	365	100%	Yes
1963	207	57%	No
1964	364	99%	Yes
1965	362	99%	Yes
1966	362	99%	Yes
1967	335	92%	Yes
1968	366	100%	Yes
1969	363	99%	Yes
1970	360	99%	Yes
1971	364	100%	Yes
1972	366	100%	Yes
1973	362	99%	Yes
1974	364	100%	Yes
1975	365	100%	Yes
1976	366	100%	Yes
1977	333	91%	Yes
1978	333	91%	Yes
1979	364	100%	Yes
1980	366	100%	Yes
1981	365	100%	Yes
1982	365	100%	Yes
1983	363	99%	Yes
1984	302	83%	No
1985	364	100%	Yes
1986	365	100%	Yes
1987	364	100%	Yes
1988	365	100%	Yes
1989	207	57%	No
1990	272	75%	No
1991	103	28%	No
1992	169	46%	No
1993	85	23%	No
1994	175	48%	No
1995	210	58%	No
1996	365	100%	Yes
1997	327	90%	No
1998	356	98%	Yes
1999	352	96%	Yes
2000	353	96%	Yes
2001	332	91%	Yes
2002	294	81%	No
2003	332	91%	Yes
2004	366	100%	Yes
2005	356	98%	Yes
2006	362	99%	Yes
2007	361	99%	Yes
2008	335	92%	Yes
2009	365	100%	Yes
2010	363	99%	Yes
2011	363	99%	Yes
2012	270	74%	No

Latest Records

Latest records at Delta
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
2 October 2012	Delta, MX	daily high max (Tie)	45.0 C (113.0 F)	tie	22 years	3 of 100 (Routine)
10 September 2012	Delta, MX	daily low max	28.9 C (84.0 F)	3.9 C (7.0 F)	36 years	25 of 100 (Routine)
31 July 2012	Delta, MX	daily low max	31.1 C (88.0 F)	2.8 C (5.0 F)	49 years	27 of 100 (Routine)
30 July 2012	Delta, MX	monthly rain	50.8 mm (2.0 in)	37.8 mm (1.5 in)	28 years	64 of 100 (Major)
17 July 2012	Delta, MX	daily low min	16.1 C (61.0 F)	0.6 C (1.1 F)	61 years	25 of 100 (Routine)
12 July 2012	Delta, MX	daily low max (Tie)	38.3 C (100.9 F)	tie	33 years	3 of 100 (Routine)
11 July 2012	Delta, MX	daily rain	2.3 mm (0.09 in)	1.5 mm (0.06 in)	13 years	13 of 100 (Routine)
29 February 2012	Delta, MX	daily low max (Tie)	18.9 C (66.0 F)	tie	56 years	5 of 100 (Routine)
29 February 2012	Delta, MX	daily low min (Tie)	2.8 C (37.0 F)	tie	48 years	5 of 100 (Routine)
13 December 2011	Delta, MX	daily rain	21.8 mm (0.9 in)	21.8 mm (0.9 in)	62 years	20 of 100 (Routine)
12 December 2011	Delta, MX	daily rain	2.3 mm (0.09 in)	1.0 mm (0.04 in)	60 years	20 of 100 (Routine)
8 December 2011	Delta, MX	daily low min	-2.2 C (28.0 F)	2.8 C (5.0 F)	49 years	28 of 100 (Routine)
5 December 2011	Delta, MX	daily low max	16.1 C (61.0 F)	0.6 C (1.1 F)	38 years	18 of 100 (Routine)
4 December 2011	Delta, MX	daily low max	11.7 C (53.1 F)	1.6 C (2.9 F)	57 years	26 of 100 (Routine)
3 December 2011	Delta, MX	daily low max	12.8 C (55.0 F)	5.0 C (9.0 F)	58 years	34 of 100 (Routine)
19 November 2011	Delta, MX	daily rain	1.3 mm (0.05 in)	1.3 mm (0.05 in)	62 years	20 of 100 (Routine)
7 November 2011	Delta, MX	daily low max (Tie)	20.0 C (68.0 F)	tie	16 years	2 of 100 (Routine)
4 November 2011	Delta, MX	daily rain	0.8 mm (0.03 in)	0.8 mm (0.03 in)	62 years	20 of 100 (Routine)
7 October 2011	Delta, MX	daily low max	26.1 C (79.0 F)	2.8 C (5.0 F)	4 years	12 of 100 (Routine)
12 September 2011	Delta, MX	daily rain	13.0 mm (0.5 in)	3.1 mm (0.12 in)	52 years	20 of 100 (Routine)

Climate Trend

46 complete years, 1949 to 2011

One stripe for each of 46 complete years at Delta, 1949 to 2011. Blue stripes are years cooler than the station's own mean of 22.9 C (73.3 F); red stripes are warmer. The coolest year was 1951, at 21.4 C (70.4 F), and the warmest was 1966, at 25.0 C (77.0 F). The strongest colour marks a difference of 2.1 C (3.8 F).

Annual mean temperature at Delta as warming stripes, 1949 to 2011
Year	Annual mean temperature	Difference from the station mean
1949	22.7 C	-0.20 C
1950	25.0 C	+2.07 C
1951	21.4 C	-1.56 C
1952	21.9 C	-1.01 C
1953	24.1 C	+1.16 C
1954	22.2 C	-0.70 C
1955	21.5 C	-1.46 C
1957	22.0 C	-0.90 C
1958	21.9 C	-1.02 C
1959	24.1 C	+1.17 C
1960	22.7 C	-0.24 C
1961	23.1 C	+0.21 C
1962	23.5 C	+0.54 C
1964	22.6 C	-0.31 C
1965	22.8 C	-0.14 C
1966	25.0 C	+2.08 C
1968	22.8 C	-0.14 C
1969	23.2 C	+0.31 C
1970	22.9 C	+0.01 C
1971	22.3 C	-0.65 C
1972	23.0 C	+0.05 C
1973	22.5 C	-0.45 C
1974	23.1 C	+0.14 C
1975	22.3 C	-0.59 C
1976	22.8 C	-0.10 C
1979	23.7 C	+0.74 C
1980	24.4 C	+1.46 C
1981	24.8 C	+1.91 C
1982	23.7 C	+0.78 C
1983	23.9 C	+1.02 C
1985	21.8 C	-1.11 C
1986	22.2 C	-0.75 C
1987	22.1 C	-0.81 C
1988	22.8 C	-0.13 C
1996	23.7 C	+0.73 C
1998	22.4 C	-0.54 C
1999	22.7 C	-0.20 C
2000	22.8 C	-0.14 C
2003	23.2 C	+0.29 C
2004	22.7 C	-0.27 C
2005	23.2 C	+0.29 C
2006	22.8 C	-0.12 C
2007	22.8 C	-0.15 C
2009	23.0 C	+0.04 C
2010	22.3 C	-0.63 C
2011	22.3 C	-0.59 C

The fitted trend in annual mean temperature here over 1949 to 2011 is -0.01 C (-0.14 to 0.13) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.01 F (-0.26 to 0.23) per decade. The slope is a straight line fitted to 46 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Delta
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.01 C (-0.14 to 0.13) per decade	-0.01 F (-0.26 to 0.23) per decade	1949 to 2011	46	Not clearly different from zero
Mean daily maximum	-0.1 C (-0.3 to 0.2) per decade	-0.1 F (-0.5 to 0.3) per decade	1949 to 2011	46	Not clearly different from zero
Mean daily minimum	0.04 C (-0.18 to 0.26) per decade	0.1 F (-0.3 to 0.5) per decade	1949 to 2011	46	Not clearly different from zero

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

1948 to 2012

Yearly extremes at Delta: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	56.7 C (134.1 F)	1953	48.9 C (120.0 F)	65
Coldest night (TNn)	-6.1 C (21.0 F)	2007	0.0 C (32.0 F)	65
Wettest day (Rx1day)	63.0 mm (2.5 in)	1972	10.4 mm (0.4 in)	65
Wettest five days (Rx5day)	105.9 mm (4.2 in)	1972	12.7 mm (0.5 in)	65
Longest dry spell (CDD)	365 days	1961	162 days	65

Hottest day (TXx)

The hottest day of the year at Delta, 1948 to 2012. The record is 56.7 C (134.1 F) in 1953, marked on the chart; the median year is 48.9 C (120.0 F).

Hottest day (TXx) at Delta by year
Year	Hottest day (TXx)
1948	55.0 C (131.0 F)
1949	51.7 C (125.1 F)
1950	51.7 C (125.1 F)
1951	46.7 C (116.1 F)
1952	45.0 C (113.0 F)
1953	56.7 C (134.1 F)
1954	47.8 C (118.0 F)
1955	48.9 C (120.0 F)
1956	53.9 C (129.0 F)
1957	47.8 C (118.0 F)
1958	47.8 C (118.0 F)
1959	47.8 C (118.0 F)
1960	46.7 C (116.1 F)
1961	47.8 C (118.0 F)
1962	45.6 C (114.1 F)
1963	45.0 C (113.0 F)
1964	47.8 C (118.0 F)
1965	46.7 C (116.1 F)
1966	55.0 C (131.0 F)
1967	46.7 C (116.1 F)
1968	48.3 C (118.9 F)
1969	47.8 C (118.0 F)
1970	47.8 C (118.0 F)
1971	45.6 C (114.1 F)
1972	48.9 C (120.0 F)
1973	48.9 C (120.0 F)
1974	48.9 C (120.0 F)
1975	47.8 C (118.0 F)
1976	48.9 C (120.0 F)
1977	48.9 C (120.0 F)
1978	48.9 C (120.0 F)
1979	45.6 C (114.1 F)
1980	46.7 C (116.1 F)
1981	47.8 C (118.0 F)
1982	45.6 C (114.1 F)
1983	46.1 C (115.0 F)
1984	49.4 C (120.9 F)
1985	50.6 C (123.1 F)
1986	50.0 C (122.0 F)
1987	48.3 C (118.9 F)
1988	49.4 C (120.9 F)
1989	47.8 C (118.0 F)
1990	50.0 C (122.0 F)
1991	50.6 C (123.1 F)
1992	50.0 C (122.0 F)
1993	40.6 C (105.1 F)
1994	40.0 C (104.0 F)
1995	51.7 C (125.1 F)
1996	50.6 C (123.1 F)
1997	50.0 C (122.0 F)
1998	53.9 C (129.0 F)
1999	48.3 C (118.9 F)
2000	50.0 C (122.0 F)
2001	48.9 C (120.0 F)
2002	48.9 C (120.0 F)
2003	50.0 C (122.0 F)
2004	48.3 C (118.9 F)
2005	50.0 C (122.0 F)
2006	48.9 C (120.0 F)
2007	47.8 C (118.0 F)
2008	49.4 C (120.9 F)
2009	50.0 C (122.0 F)
2010	47.2 C (117.0 F)
2011	49.4 C (120.9 F)
2012	48.9 C (120.0 F)

Coldest night (TNn)

The coldest night of the year at Delta, 1948 to 2012. The record is -6.1 C (21.0 F) in 2007, marked on the chart; the median year is 0.0 C (32.0 F).

Coldest night (TNn) at Delta by year
Year	Coldest night (TNn)
1948	-2.2 C (28.0 F)
1949	0.0 C (32.0 F)
1950	-1.1 C (30.0 F)
1951	-2.2 C (28.0 F)
1952	0.0 C (32.0 F)
1953	0.0 C (32.0 F)
1954	0.0 C (32.0 F)
1955	0.0 C (32.0 F)
1956	0.0 C (32.0 F)
1957	1.7 C (35.1 F)
1958	0.0 C (32.0 F)
1959	0.0 C (32.0 F)
1960	0.0 C (32.0 F)
1961	0.6 C (33.1 F)
1962	0.0 C (32.0 F)
1963	0.6 C (33.1 F)
1964	-3.3 C (26.1 F)
1965	0.0 C (32.0 F)
1966	-2.2 C (28.0 F)
1967	0.0 C (32.0 F)
1968	0.0 C (32.0 F)
1969	0.0 C (32.0 F)
1970	-2.2 C (28.0 F)
1971	-3.3 C (26.1 F)
1972	-2.2 C (28.0 F)
1973	-1.1 C (30.0 F)
1974	-1.1 C (30.0 F)
1975	-1.1 C (30.0 F)
1976	-3.3 C (26.1 F)
1977	0.6 C (33.1 F)
1978	1.7 C (35.1 F)
1979	2.2 C (36.0 F)
1980	5.0 C (41.0 F)
1981	4.4 C (39.9 F)
1982	3.9 C (39.0 F)
1983	3.3 C (37.9 F)
1984	1.7 C (35.1 F)
1985	0.6 C (33.1 F)
1986	0.0 C (32.0 F)
1987	-2.2 C (28.0 F)
1988	-3.3 C (26.1 F)
1989	0.0 C (32.0 F)
1990	0.6 C (33.1 F)
1991	10.0 C (50.0 F)
1992	5.0 C (41.0 F)
1993	13.9 C (57.0 F)
1994	0.0 C (32.0 F)
1995	0.0 C (32.0 F)
1996	-3.3 C (26.1 F)
1997	-5.0 C (23.0 F)
1998	-3.3 C (26.1 F)
1999	-2.2 C (28.0 F)
2000	0.0 C (32.0 F)
2001	0.0 C (32.0 F)
2002	-2.2 C (28.0 F)
2003	-2.2 C (28.0 F)
2004	0.0 C (32.0 F)
2005	-1.1 C (30.0 F)
2006	-2.2 C (28.0 F)
2007	-6.1 C (21.0 F)
2008	-1.1 C (30.0 F)
2009	0.0 C (32.0 F)
2010	-3.3 C (26.1 F)
2011	-3.9 C (25.0 F)
2012	1.1 C (34.0 F)

Wettest day (Rx1day)

The wettest day of the year at Delta, 1948 to 2012. The record is 63.0 mm (2.5 in) in 1972, marked on the chart; the median year is 10.4 mm (0.4 in).

Wettest day (Rx1day) at Delta by year
Year	Wettest day (Rx1day)
1948	27.9 mm (1.1 in)
1949	24.9 mm (1.0 in)
1950	4.8 mm (0.19 in)
1951	10.9 mm (0.4 in)
1952	11.9 mm (0.5 in)
1953	9.9 mm (0.39 in)
1954	1.8 mm (0.07 in)
1955	16.8 mm (0.7 in)
1956	5.8 mm (0.23 in)
1957	8.9 mm (0.35 in)
1958	9.9 mm (0.39 in)
1959	16.8 mm (0.7 in)
1960	7.9 mm (0.31 in)
1961	0.0 mm (0.00 in)
1962	0.0 mm (0.00 in)
1963	0.0 mm (0.00 in)
1964	0.0 mm (0.00 in)
1965	0.0 mm (0.00 in)
1966	0.0 mm (0.00 in)
1967	0.0 mm (0.00 in)
1968	0.0 mm (0.00 in)
1969	7.9 mm (0.31 in)
1970	17.8 mm (0.7 in)
1971	18.8 mm (0.7 in)
1972	63.0 mm (2.5 in)
1973	7.9 mm (0.31 in)
1974	15.0 mm (0.6 in)
1975	9.4 mm (0.37 in)
1976	38.4 mm (1.5 in)
1977	14.0 mm (0.6 in)
1978	37.3 mm (1.5 in)
1979	45.0 mm (1.8 in)
1980	5.1 mm (0.20 in)
1981	30.5 mm (1.2 in)
1982	43.9 mm (1.7 in)
1983	40.4 mm (1.6 in)
1984	13.0 mm (0.5 in)
1985	11.7 mm (0.5 in)
1986	7.9 mm (0.31 in)
1987	6.4 mm (0.25 in)
1988	9.9 mm (0.39 in)
1989	7.9 mm (0.31 in)
1990	11.4 mm (0.4 in)
1991	0.0 mm (0.00 in)
1992	24.9 mm (1.0 in)
1993	3.3 mm (0.13 in)
1994	1.3 mm (0.05 in)
1995	0.8 mm (0.03 in)
1996	10.9 mm (0.4 in)
1997	18.8 mm (0.7 in)
1998	7.4 mm (0.29 in)
1999	16.3 mm (0.6 in)
2000	7.4 mm (0.29 in)
2001	15.0 mm (0.6 in)
2002	3.3 mm (0.13 in)
2003	13.0 mm (0.5 in)
2004	20.3 mm (0.8 in)
2005	10.4 mm (0.4 in)
2006	4.8 mm (0.19 in)
2007	21.8 mm (0.9 in)
2008	37.8 mm (1.5 in)
2009	5.8 mm (0.23 in)
2010	31.8 mm (1.3 in)
2011	21.8 mm (0.9 in)
2012	50.8 mm (2.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Delta, 1948 to 2012. The record is 105.9 mm (4.2 in) in 1972, marked on the chart; the median year is 12.7 mm (0.5 in).

Wettest five days (Rx5day) at Delta by year
Year	Wettest five days (Rx5day)
1948	35.8 mm (1.4 in)
1949	39.9 mm (1.6 in)
1950	4.8 mm (0.19 in)
1951	25.6 mm (1.0 in)
1952	11.9 mm (0.5 in)
1953	9.9 mm (0.39 in)
1954	2.1 mm (0.08 in)
1955	23.6 mm (0.9 in)
1956	5.8 mm (0.23 in)
1957	12.7 mm (0.5 in)
1958	13.7 mm (0.5 in)
1959	29.8 mm (1.2 in)
1960	8.7 mm (0.34 in)
1961	0.0 mm (0.00 in)
1962	0.0 mm (0.00 in)
1963	0.0 mm (0.00 in)
1964	0.0 mm (0.00 in)
1965	0.0 mm (0.00 in)
1966	0.0 mm (0.00 in)
1967	0.0 mm (0.00 in)
1968	0.0 mm (0.00 in)
1969	7.9 mm (0.31 in)
1970	18.8 mm (0.7 in)
1971	19.6 mm (0.8 in)
1972	105.9 mm (4.2 in)
1973	10.7 mm (0.4 in)
1974	17.3 mm (0.7 in)
1975	12.7 mm (0.5 in)
1976	71.9 mm (2.8 in)
1977	31.3 mm (1.2 in)
1978	62.9 mm (2.5 in)
1979	46.3 mm (1.8 in)
1980	10.9 mm (0.4 in)
1981	30.5 mm (1.2 in)
1982	58.9 mm (2.3 in)
1983	61.5 mm (2.4 in)
1984	21.6 mm (0.9 in)
1985	12.7 mm (0.5 in)
1986	7.9 mm (0.31 in)
1987	11.5 mm (0.5 in)
1988	16.8 mm (0.7 in)
1989	7.9 mm (0.31 in)
1990	14.7 mm (0.6 in)
1991	0.0 mm (0.00 in)
1992	44.7 mm (1.8 in)
1993	3.3 mm (0.13 in)
1994	1.8 mm (0.07 in)
1995	0.8 mm (0.03 in)
1996	10.9 mm (0.4 in)
1997	18.8 mm (0.7 in)
1998	7.4 mm (0.29 in)
1999	16.3 mm (0.6 in)
2000	7.4 mm (0.29 in)
2001	21.4 mm (0.8 in)
2002	3.6 mm (0.14 in)
2003	14.8 mm (0.6 in)
2004	20.3 mm (0.8 in)
2005	15.2 mm (0.6 in)
2006	7.6 mm (0.30 in)
2007	21.8 mm (0.9 in)
2008	37.8 mm (1.5 in)
2009	7.6 mm (0.30 in)
2010	67.4 mm (2.7 in)
2011	24.1 mm (0.9 in)
2012	50.8 mm (2.0 in)

Longest dry spell (CDD)

The longest dry spell of the year at Delta, 1948 to 2012. The record is 365 days in 1961, marked on the chart; the median year is 162 days.

Longest dry spell (CDD) at Delta by year
Year	Longest dry spell (CDD)
1948	102 days
1949	317 days
1950	249 days
1951	237 days
1952	215 days
1953	305 days
1954	285 days
1955	166 days
1956	128 days
1957	152 days
1958	157 days
1959	138 days
1960	117 days
1961	365 days
1962	365 days
1963	365 days
1964	306 days
1965	365 days
1966	365 days
1967	365 days
1968	306 days
1969	246 days
1970	158 days
1971	107 days
1972	155 days
1973	160 days
1974	202 days
1975	149 days
1976	148 days
1977	113 days
1978	151 days
1979	92 days
1980	247 days
1981	160 days
1982	133 days
1983	153 days
1984	190 days
1985	224 days
1986	252 days
1987	302 days
1988	131 days
1989	148 days
1990	102 days
1991	105 days
1992	130 days
1993	75 days
1994	292 days
1995	187 days
1996	165 days
1997	67 days
1998	176 days
1999	104 days
2000	210 days
2001	147 days
2002	161 days
2003	259 days
2004	200 days
2005	76 days
2006	163 days
2007	162 days
2008	213 days
2009	327 days
2010	162 days
2011	112 days
2012	69 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

21 years with a frost

Across 21 years with a frost, the median last spring frost at Delta falls on 13 February and the median first autumn frost on 11 December, which leaves a median of 306 days between them.

Frost dates and growing season at Delta
Measure	Median, all years	Earliest period	Recent period (1949 to 2011)	Recent against earliest	Fitted trend
Last spring frost	13 February	n/a	13 February	n/a	n/a
First autumn frost	11 December	n/a	11 December	n/a	n/a
Growing days	306 days	n/a	306 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.

Rainfall Return Levels

55 years, 1949 to 2011

A day with at least 10.8 mm (0.4 in) of rain is expected about once in 2 years. A day with at least 70.6 mm (2.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Delta: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	10.8 mm (0.4 in)
5 years	22.3 mm (0.9 in)
10 years	31.4 mm (1.2 in)
25 years	45.1 mm (1.8 in)
50 years	57.0 mm (2.2 in)
100 years	70.6 mm (2.8 in)	Longer than the 55 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, 55 years of values from 1949 to 2011.

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: 63.0 mm (2.5 in) in 1972; 45.0 mm (1.8 in) in 1979; 43.9 mm (1.7 in) in 1982.

Download the Data

Data for Delta standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Delta 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 2026-10-13 (13 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).