Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at San Isidro. 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 San Isidro, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
28.9 C (84.0 F)
-6.1 C (21.0 F)
n/a
n/a
Feb
30.6 C (87.1 F)
-6.1 C (21.0 F)
n/a
n/a
Mar
32.8 C (91.0 F)
-3.3 C (26.1 F)
n/a
n/a
Apr
36.7 C (98.1 F)
-1.1 C (30.0 F)
n/a
n/a
May
36.7 C (98.1 F)
2.8 C (37.0 F)
n/a
n/a
Jun
35.6 C (96.1 F)
5.0 C (41.0 F)
n/a
n/a
Jul
35.6 C (96.1 F)
5.0 C (41.0 F)
n/a
n/a
Aug
35.0 C (95.0 F)
6.7 C (44.1 F)
n/a
n/a
Sep
32.8 C (91.0 F)
2.8 C (37.0 F)
n/a
n/a
Oct
31.7 C (89.1 F)
0.0 C (32.0 F)
n/a
n/a
Nov
31.7 C (89.1 F)
-6.1 C (21.0 F)
n/a
n/a
Dec
28.9 C (84.0 F)
-6.1 C (21.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at San Isidro still stand. 2003 holds the most, with 121.
Standing records at San Isidro by the year they were set
Year set
Standing records
1968
4
1970
41
1971
46
1972
43
1973
47
1974
34
1975
54
1976
42
1977
28
1978
33
1979
32
1980
13
1981
12
1982
19
1983
38
1984
31
1985
32
1986
53
1987
35
1988
58
1989
56
1990
31
1991
17
1992
42
1993
23
1994
10
1995
33
1996
8
1997
13
1998
24
1999
8
2000
72
2001
58
2002
72
2003
121
2004
14
2005
27
2006
12
2007
18
2008
69
2009
12
2010
16
2011
5
2012
7
2013
1
All-Time Record Progression
4 new records
4 all-time records were set at San Isidro between 17 April 2001 and 26 June 2007. Each dot is a new record.
When San Isidro set new all-time records
Date
Kind
Detail
2001-04-17
Record high maximum temperature
Record high maximum temperature 36.7 C (98.1 F)
2001-07-31
Record high minimum temperature
Record high minimum temperature 18.9 C (66.0 F)
2005-06-30
Record high minimum temperature
Record high minimum temperature 20.0 C (68.0 F)
2007-06-26
Record daily precipitation
Record daily precipitation 90.4 mm (3.6 in)
Wettest Day of Each Month
Jun: 90.4 mm (3.6 in)
The wettest day on record for each calendar month at San Isidro. The most was 90.4 mm (3.6 in) on 26 June 2007.
Record daily precipitation for each month at San Isidro
Month
Record daily precipitation (mm)
Date
Jan
40.9 mm (1.6 in)
1 January 2013
Feb
45.0 mm (1.8 in)
23 February 1970
Mar
14.2 mm (0.6 in)
21 March 1997
Apr
19.8 mm (0.8 in)
19 April 1994
May
48.8 mm (1.9 in)
25 May 1971
Jun
90.4 mm (3.6 in)
26 June 2007
Jul
68.8 mm (2.7 in)
7 July 1985
Aug
79.0 mm (3.1 in)
24 August 1992
Sep
75.2 mm (3.0 in)
22 September 1967
Oct
54.4 mm (2.1 in)
9 October 1992
Nov
48.3 mm (1.9 in)
14 November 1992
Dec
42.9 mm (1.7 in)
10 December 2006
Period of Record Coverage
1968 to 2013
Complete yearUnder 90 percent of days
45 years of record at San Isidro, 1968 to 2013. 8 years have data for under 90 percent of days and are left out of rankings: 1968, 1970, 1976, 1980, 1981, 1982, 2001, 2013.
Cooler than the station meanWarmer than the station mean
One stripe for each of 34 complete years at San Isidro, 1973 to 2011. Blue stripes are years cooler than the station's own mean of 16.4 C (61.6 F); red stripes are warmer. The coolest year was 1988, at 15.1 C (59.2 F), and the warmest was 2003, at 19.0 C (66.2 F). The strongest colour marks a difference of 2.6 C (4.7 F).
Annual mean temperature at San Isidro as warming stripes, 1973 to 2011
Year
Annual mean temperature
Difference from the station mean
1973
16.5 C
+0.09 C
1974
16.3 C
-0.13 C
1975
15.5 C
-0.94 C
1977
16.2 C
-0.27 C
1978
15.9 C
-0.52 C
1979
16.1 C
-0.34 C
1983
15.6 C
-0.87 C
1984
15.5 C
-0.90 C
1985
15.8 C
-0.69 C
1986
15.6 C
-0.89 C
1987
16.0 C
-0.42 C
1988
15.1 C
-1.31 C
1989
15.2 C
-1.21 C
1990
15.7 C
-0.72 C
1991
15.9 C
-0.52 C
1992
15.4 C
-1.00 C
1993
15.9 C
-0.50 C
1994
16.8 C
+0.39 C
1995
16.6 C
+0.15 C
1996
16.4 C
-0.03 C
1997
16.1 C
-0.34 C
1998
16.8 C
+0.36 C
1999
16.2 C
-0.28 C
2000
17.9 C
+1.46 C
2002
17.8 C
+1.36 C
2003
19.0 C
+2.55 C
2004
16.9 C
+0.50 C
2005
17.7 C
+1.22 C
2006
17.4 C
+0.95 C
2007
17.3 C
+0.85 C
2008
17.7 C
+1.21 C
2009
16.8 C
+0.31 C
2010
16.1 C
-0.36 C
2011
17.3 C
+0.83 C
The annual mean temperature here has risen by 0.5 C (0.3 to 0.7) per decade over 1973 to 2011. In Fahrenheit: 0.9 F (0.5 to 1.3) per decade. The slope is a straight line fitted to 34 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at San Isidro
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
1973 to 2011
34
Rise
Mean daily maximum
0.7 C (0.3 to 1.0) per decade
1.2 F (0.6 to 1.8) per decade
1973 to 2011
34
Rise
Mean daily minimum
0.3 C (0.1 to 0.5) per decade
0.6 F (0.1 to 1.0) per decade
1973 to 2011
34
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
1967 to 2013
Yearly extremes at San Isidro: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.7 C (98.1 F)
2001
32.8 C (91.0 F)
45
Coldest night (TNn)
-6.1 C (21.0 F)
1970
-3.3 C (26.1 F)
44
Wettest day (Rx1day)
90.4 mm (3.6 in)
2007
40.9 mm (1.6 in)
47
Wettest five days (Rx5day)
195.4 mm (7.7 in)
1967
77.9 mm (3.1 in)
47
Longest dry spell (CDD)
171 days
2011
92 days
47
Hottest day (TXx)
The hottest day of the year at San Isidro, 1967 to 2013. The record is 36.7 C (98.1 F) in 2001, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at San Isidro by year
Year
Hottest day (TXx)
1967
n/a
1968
35.6 C (96.1 F)
1969
n/a
1970
28.9 C (84.0 F)
1971
33.9 C (93.0 F)
1972
35.0 C (95.0 F)
1973
35.0 C (95.0 F)
1974
33.9 C (93.0 F)
1975
31.7 C (89.1 F)
1976
32.8 C (91.0 F)
1977
32.8 C (91.0 F)
1978
32.8 C (91.0 F)
1979
30.6 C (87.1 F)
1980
32.8 C (91.0 F)
1981
30.0 C (86.0 F)
1982
33.9 C (93.0 F)
1983
32.2 C (90.0 F)
1984
31.7 C (89.1 F)
1985
32.8 C (91.0 F)
1986
33.9 C (93.0 F)
1987
31.7 C (89.1 F)
1988
32.8 C (91.0 F)
1989
35.6 C (96.1 F)
1990
33.9 C (93.0 F)
1991
33.3 C (91.9 F)
1992
31.7 C (89.1 F)
1993
32.8 C (91.0 F)
1994
31.7 C (89.1 F)
1995
31.7 C (89.1 F)
1996
32.8 C (91.0 F)
1997
31.7 C (89.1 F)
1998
33.9 C (93.0 F)
1999
31.7 C (89.1 F)
2000
32.8 C (91.0 F)
2001
36.7 C (98.1 F)
2002
35.6 C (96.1 F)
2003
36.7 C (98.1 F)
2004
33.9 C (93.0 F)
2005
35.6 C (96.1 F)
2006
33.9 C (93.0 F)
2007
35.0 C (95.0 F)
2008
36.7 C (98.1 F)
2009
32.8 C (91.0 F)
2010
32.8 C (91.0 F)
2011
32.8 C (91.0 F)
2012
31.7 C (89.1 F)
2013
31.7 C (89.1 F)
Coldest night (TNn)
The coldest night of the year at San Isidro, 1967 to 2013. The record is -6.1 C (21.0 F) in 1970, marked on the chart; the median year is -3.3 C (26.1 F).
Coldest night (TNn) at San Isidro by year
Year
Coldest night (TNn)
1967
n/a
1968
n/a
1969
n/a
1970
-6.1 C (21.0 F)
1971
-2.2 C (28.0 F)
1972
-6.1 C (21.0 F)
1973
-6.1 C (21.0 F)
1974
-4.4 C (24.1 F)
1975
-5.0 C (23.0 F)
1976
-3.3 C (26.1 F)
1977
-2.2 C (28.0 F)
1978
-5.0 C (23.0 F)
1979
-2.2 C (28.0 F)
1980
0.0 C (32.0 F)
1981
-2.2 C (28.0 F)
1982
-3.3 C (26.1 F)
1983
-4.4 C (24.1 F)
1984
-3.3 C (26.1 F)
1985
-3.3 C (26.1 F)
1986
-3.3 C (26.1 F)
1987
0.0 C (32.0 F)
1988
-4.4 C (24.1 F)
1989
-4.4 C (24.1 F)
1990
0.0 C (32.0 F)
1991
-3.3 C (26.1 F)
1992
0.0 C (32.0 F)
1993
0.0 C (32.0 F)
1994
-2.2 C (28.0 F)
1995
0.6 C (33.1 F)
1996
0.0 C (32.0 F)
1997
-6.1 C (21.0 F)
1998
-2.2 C (28.0 F)
1999
-4.4 C (24.1 F)
2000
-5.0 C (23.0 F)
2001
-2.2 C (28.0 F)
2002
-3.3 C (26.1 F)
2003
-2.2 C (28.0 F)
2004
-3.3 C (26.1 F)
2005
-2.2 C (28.0 F)
2006
-6.1 C (21.0 F)
2007
-5.0 C (23.0 F)
2008
-3.3 C (26.1 F)
2009
-2.2 C (28.0 F)
2010
-6.1 C (21.0 F)
2011
-2.2 C (28.0 F)
2012
0.0 C (32.0 F)
2013
0.0 C (32.0 F)
Wettest day (Rx1day)
The wettest day of the year at San Isidro, 1967 to 2013. The record is 90.4 mm (3.6 in) in 2007, marked on the chart; the median year is 40.9 mm (1.6 in).
Wettest day (Rx1day) at San Isidro by year
Year
Wettest day (Rx1day)
1967
75.2 mm (3.0 in)
1968
24.1 mm (0.9 in)
1969
38.9 mm (1.5 in)
1970
45.0 mm (1.8 in)
1971
48.8 mm (1.9 in)
1972
38.9 mm (1.5 in)
1973
39.9 mm (1.6 in)
1974
31.8 mm (1.3 in)
1975
62.0 mm (2.4 in)
1976
59.9 mm (2.4 in)
1977
39.9 mm (1.6 in)
1978
46.0 mm (1.8 in)
1979
59.9 mm (2.4 in)
1980
19.8 mm (0.8 in)
1981
18.8 mm (0.7 in)
1982
30.0 mm (1.2 in)
1983
36.8 mm (1.4 in)
1984
36.8 mm (1.4 in)
1985
68.8 mm (2.7 in)
1986
63.0 mm (2.5 in)
1987
47.8 mm (1.9 in)
1988
50.8 mm (2.0 in)
1989
25.9 mm (1.0 in)
1990
49.8 mm (2.0 in)
1991
45.5 mm (1.8 in)
1992
79.0 mm (3.1 in)
1993
37.8 mm (1.5 in)
1994
37.6 mm (1.5 in)
1995
42.7 mm (1.7 in)
1996
32.3 mm (1.3 in)
1997
20.6 mm (0.8 in)
1998
45.0 mm (1.8 in)
1999
76.7 mm (3.0 in)
2000
49.3 mm (1.9 in)
2001
41.1 mm (1.6 in)
2002
39.9 mm (1.6 in)
2003
34.8 mm (1.4 in)
2004
35.6 mm (1.4 in)
2005
46.0 mm (1.8 in)
2006
42.9 mm (1.7 in)
2007
90.4 mm (3.6 in)
2008
32.8 mm (1.3 in)
2009
55.1 mm (2.2 in)
2010
37.8 mm (1.5 in)
2011
36.3 mm (1.4 in)
2012
40.9 mm (1.6 in)
2013
40.9 mm (1.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at San Isidro, 1967 to 2013. The record is 195.4 mm (7.7 in) in 1967, marked on the chart; the median year is 77.9 mm (3.1 in).
Wettest five days (Rx5day) at San Isidro by year
Year
Wettest five days (Rx5day)
1967
195.4 mm (7.7 in)
1968
59.5 mm (2.3 in)
1969
69.4 mm (2.7 in)
1970
98.0 mm (3.9 in)
1971
83.9 mm (3.3 in)
1972
84.9 mm (3.3 in)
1973
93.2 mm (3.7 in)
1974
72.2 mm (2.8 in)
1975
163.9 mm (6.5 in)
1976
125.5 mm (4.9 in)
1977
86.4 mm (3.4 in)
1978
95.8 mm (3.8 in)
1979
104.4 mm (4.1 in)
1980
39.6 mm (1.6 in)
1981
36.6 mm (1.4 in)
1982
49.6 mm (2.0 in)
1983
63.5 mm (2.5 in)
1984
70.0 mm (2.8 in)
1985
78.7 mm (3.1 in)
1986
132.3 mm (5.2 in)
1987
69.1 mm (2.7 in)
1988
121.3 mm (4.8 in)
1989
42.1 mm (1.7 in)
1990
75.5 mm (3.0 in)
1991
147.6 mm (5.8 in)
1992
114.5 mm (4.5 in)
1993
67.8 mm (2.7 in)
1994
56.9 mm (2.2 in)
1995
80.5 mm (3.2 in)
1996
87.8 mm (3.5 in)
1997
41.7 mm (1.6 in)
1998
72.7 mm (2.9 in)
1999
87.6 mm (3.4 in)
2000
64.6 mm (2.5 in)
2001
77.9 mm (3.1 in)
2002
51.3 mm (2.0 in)
2003
90.2 mm (3.6 in)
2004
50.9 mm (2.0 in)
2005
81.0 mm (3.2 in)
2006
55.9 mm (2.2 in)
2007
118.1 mm (4.6 in)
2008
51.6 mm (2.0 in)
2009
66.0 mm (2.6 in)
2010
86.7 mm (3.4 in)
2011
56.4 mm (2.2 in)
2012
78.3 mm (3.1 in)
2013
65.1 mm (2.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at San Isidro, 1967 to 2013. The record is 171 days in 2011, marked on the chart; the median year is 92 days.
Longest dry spell (CDD) at San Isidro by year
Year
Longest dry spell (CDD)
1967
47 days
1968
96 days
1969
127 days
1970
97 days
1971
85 days
1972
40 days
1973
75 days
1974
55 days
1975
150 days
1976
91 days
1977
82 days
1978
85 days
1979
112 days
1980
51 days
1981
36 days
1982
76 days
1983
127 days
1984
128 days
1985
77 days
1986
155 days
1987
53 days
1988
65 days
1989
108 days
1990
67 days
1991
112 days
1992
67 days
1993
82 days
1994
90 days
1995
89 days
1996
113 days
1997
50 days
1998
159 days
1999
156 days
2000
142 days
2001
104 days
2002
89 days
2003
111 days
2004
92 days
2005
117 days
2006
106 days
2007
109 days
2008
92 days
2009
58 days
2010
113 days
2011
171 days
2012
75 days
2013
130 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
27 years with a frost
Across 27 years with a frost, the median last spring frost at San Isidro falls on 22 February and the median first autumn frost on 28 November, which leaves a median of 282 days between them.
Fitted over all years, the growing season changes by +9.6 days per decade at this station.
Frost dates and growing season at San Isidro
Measure
Median, all years
Earliest period
Recent period (1973 to 2011)
Recent against earliest
Fitted trend
Last spring frost
22 February
n/a
22 February
n/a
-7.6 days per decade
First autumn frost
28 November
n/a
28 November
n/a
+2.0 days per decade
Growing days
282 days
n/a
282 days
n/a
+9.6 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
41 years, 1968 to 2012
A day with at least 42.0 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 97.6 mm (3.8 in) of rain is expected about once in 100 years.
Rainfall return levels at San Isidro: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
42.0 mm (1.7 in)
5 years
54.5 mm (2.1 in)
10 years
63.7 mm (2.5 in)
25 years
76.3 mm (3.0 in)
50 years
86.6 mm (3.4 in)
Longer than the 41 years of record
100 years
97.6 mm (3.8 in)
Longer than the 41 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, 41 years of values from 1968 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: 90.4 mm (3.6 in) in 2007; 79.0 mm (3.1 in) in 1992; 76.7 mm (3.0 in) in 1999.
Download the Data
Data for San Isidro standing records by year: CSV or JSON. Field meanings are on the data page.
Data for San Isidro 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.