Record envelope, standing records and threshold days for San Luis Dam (USC00047846), California, United States, with 45 years of record.
Key Facts for San Luis Dam
San Luis Dam (USC00047846) is a weather station in California, United States at 37.05 latitude and -121.06 longitude, 84 m (277 ft) above sea level.
The station reports from 1963 to 2007, 45 years of record.
1,464 records set at San Luis Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
San Luis Dam tied a daily record high minimum temperature of 25.0 C (77.0 F) on 31 August 2007.
About the Station
Location: California, United States, 37.05 latitude, -121.06 longitude.
Elevation: 84 m (277 ft).
Period of record: 1963 to 2007, 45 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at San Luis Dam. 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 Luis Dam, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
22.8 C (73.0 F)
-6.1 C (21.0 F)
n/a
n/a
Feb
26.1 C (79.0 F)
-5.6 C (21.9 F)
n/a
n/a
Mar
29.4 C (84.9 F)
-2.2 C (28.0 F)
n/a
n/a
Apr
35.6 C (96.1 F)
0.0 C (32.0 F)
n/a
n/a
May
40.0 C (104.0 F)
2.2 C (36.0 F)
n/a
n/a
Jun
41.1 C (106.0 F)
4.4 C (39.9 F)
n/a
n/a
Jul
43.3 C (109.9 F)
6.7 C (44.1 F)
n/a
n/a
Aug
41.7 C (107.1 F)
7.2 C (45.0 F)
n/a
n/a
Sep
40.6 C (105.1 F)
7.2 C (45.0 F)
n/a
n/a
Oct
38.3 C (100.9 F)
0.6 C (33.1 F)
n/a
n/a
Nov
27.2 C (81.0 F)
-2.2 C (28.0 F)
n/a
n/a
Dec
23.9 C (75.0 F)
-10.0 C (14.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at San Luis Dam still stand. 1972 holds the most, with 53.
Standing records at San Luis Dam by the year they were set
Year set
Standing records
1963
52
1964
52
1965
23
1966
35
1967
42
1968
38
1969
40
1970
38
1971
38
1972
53
1973
32
1974
22
1975
36
1976
29
1977
28
1978
35
1979
26
1980
43
1981
27
1982
29
1983
31
1984
41
1985
42
1986
29
1987
32
1988
41
1989
33
1990
39
1991
38
1992
22
1993
21
1994
22
1995
29
1996
51
1997
20
1998
38
1999
21
2000
26
2001
25
2002
22
2003
24
2004
35
2005
14
2006
32
2007
18
All-Time Record Progression
7 new records
7 all-time records were set at San Luis Dam between 11 March 1995 and 24 July 2006. Each dot is a new record.
When San Luis Dam set new all-time records
Date
Kind
Detail
1995-03-11
Record daily precipitation
Record daily precipitation 47.2 mm (1.9 in)
1996-08-12
Record high minimum temperature
Record high minimum temperature 28.3 C (82.9 F)
1998-02-03
Record daily precipitation
Record daily precipitation 64.8 mm (2.6 in)
1998-05-06
Record daily precipitation
Record daily precipitation 94.0 mm (3.7 in)
2001-01-09
Record daily snowfall
Record daily snowfall 3.0 cm (1.2 in)
2006-07-16
Record high minimum temperature
Record high minimum temperature 29.4 C (84.9 F)
2006-07-24
Record high maximum temperature
Record high maximum temperature 43.3 C (109.9 F)
Wettest Day of Each Month
May: 94.0 mm (3.7 in)
The wettest day on record for each calendar month at San Luis Dam. The most was 94.0 mm (3.7 in) on 6 May 1998.
Record daily precipitation for each month at San Luis Dam
Month
Record daily precipitation (mm)
Date
Jan
39.1 mm (1.5 in)
19 January 1969
Feb
64.8 mm (2.6 in)
3 February 1998
Mar
47.2 mm (1.9 in)
11 March 1995
Apr
25.9 mm (1.0 in)
7 April 1963
May
94.0 mm (3.7 in)
6 May 1998
Jun
15.5 mm (0.6 in)
13 June 2005
Jul
9.9 mm (0.39 in)
10 July 1974
Aug
23.9 mm (0.9 in)
31 August 1983
Sep
43.4 mm (1.7 in)
29 September 1976
Oct
29.5 mm (1.2 in)
27 October 2000
Nov
40.6 mm (1.6 in)
17 November 1965
Dec
39.4 mm (1.6 in)
3 December 1974
Period of Record Coverage
1963 to 2007
Complete yearUnder 90 percent of days
45 years of record at San Luis Dam, 1963 to 2007. 1 years have data for under 90 percent of days and are left out of rankings: 2007.
Cooler than the station meanWarmer than the station mean
One stripe for each of 43 complete years at San Luis Dam, 1964 to 2006. 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 1982, at 15.7 C (60.2 F), and the warmest was 2005, at 17.8 C (64.0 F). The strongest colour marks a difference of 1.2 C (2.2 F).
Annual mean temperature at San Luis Dam as warming stripes, 1964 to 2006
Year
Annual mean temperature
Difference from the station mean
1964
16.2 C
-0.63 C
1965
16.1 C
-0.78 C
1966
17.1 C
+0.18 C
1967
16.8 C
-0.03 C
1968
16.8 C
-0.12 C
1969
16.2 C
-0.68 C
1970
16.9 C
+0.06 C
1971
15.7 C
-1.15 C
1972
16.2 C
-0.63 C
1973
16.6 C
-0.30 C
1974
16.5 C
-0.33 C
1975
15.7 C
-1.14 C
1976
16.6 C
-0.26 C
1977
16.9 C
+0.00 C
1978
16.7 C
-0.13 C
1979
17.0 C
+0.09 C
1980
16.5 C
-0.42 C
1981
17.5 C
+0.63 C
1982
15.7 C
-1.19 C
1983
16.6 C
-0.30 C
1984
17.1 C
+0.27 C
1985
16.5 C
-0.42 C
1986
17.3 C
+0.42 C
1987
17.1 C
+0.19 C
1988
17.5 C
+0.61 C
1989
16.6 C
-0.26 C
1990
17.3 C
+0.39 C
1991
17.0 C
+0.10 C
1992
17.8 C
+0.89 C
1993
16.6 C
-0.29 C
1994
16.2 C
-0.66 C
1995
17.3 C
+0.46 C
1996
17.7 C
+0.83 C
1997
17.8 C
+0.90 C
1998
16.3 C
-0.58 C
1999
16.5 C
-0.36 C
2000
17.4 C
+0.48 C
2001
17.8 C
+0.93 C
2002
17.2 C
+0.29 C
2003
17.6 C
+0.77 C
2004
17.4 C
+0.54 C
2005
17.8 C
+0.93 C
2006
17.4 C
+0.49 C
The annual mean temperature here has risen by 0.3 C (0.2 to 0.4) per decade over 1964 to 2006. In Fahrenheit: 0.5 F (0.3 to 0.7) per decade. The slope is a straight line fitted to 43 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at San Luis Dam
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.3 C (0.2 to 0.4) per decade
0.5 F (0.3 to 0.7) per decade
1964 to 2006
43
Rise
Mean daily maximum
0.3 C (0.2 to 0.5) per decade
0.6 F (0.3 to 0.8) per decade
1964 to 2006
43
Rise
Mean daily minimum
0.2 C (0.1 to 0.4) per decade
0.4 F (0.2 to 0.6) per decade
1964 to 2006
43
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 2007
Yearly extremes at San Luis Dam: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
43.3 C (109.9 F)
2006
41.1 C (106.0 F)
45
Coldest night (TNn)
-10.0 C (14.0 F)
1990
-3.3 C (26.1 F)
45
Wettest day (Rx1day)
94.0 mm (3.7 in)
1998
29.0 mm (1.1 in)
45
Wettest five days (Rx5day)
133.6 mm (5.3 in)
1998
51.1 mm (2.0 in)
45
Longest dry spell (CDD)
209 days
1995
119 days
45
Hottest day (TXx)
The hottest day of the year at San Luis Dam, 1963 to 2007. The record is 43.3 C (109.9 F) in 2006, marked on the chart; the median year is 41.1 C (106.0 F).
Hottest day (TXx) at San Luis Dam by year
Year
Hottest day (TXx)
1963
40.0 C (104.0 F)
1964
41.1 C (106.0 F)
1965
39.4 C (102.9 F)
1966
41.1 C (106.0 F)
1967
40.6 C (105.1 F)
1968
40.0 C (104.0 F)
1969
38.3 C (100.9 F)
1970
41.1 C (106.0 F)
1971
41.1 C (106.0 F)
1972
41.1 C (106.0 F)
1973
41.1 C (106.0 F)
1974
38.9 C (102.0 F)
1975
40.0 C (104.0 F)
1976
40.0 C (104.0 F)
1977
40.0 C (104.0 F)
1978
41.1 C (106.0 F)
1979
40.6 C (105.1 F)
1980
40.6 C (105.1 F)
1981
40.0 C (104.0 F)
1982
38.3 C (100.9 F)
1983
41.1 C (106.0 F)
1984
40.6 C (105.1 F)
1985
40.6 C (105.1 F)
1986
38.9 C (102.0 F)
1987
38.9 C (102.0 F)
1988
41.7 C (107.1 F)
1989
41.7 C (107.1 F)
1990
42.2 C (108.0 F)
1991
41.7 C (107.1 F)
1992
41.1 C (106.0 F)
1993
41.1 C (106.0 F)
1994
40.0 C (104.0 F)
1995
41.1 C (106.0 F)
1996
41.7 C (107.1 F)
1997
41.1 C (106.0 F)
1998
41.7 C (107.1 F)
1999
42.2 C (108.0 F)
2000
40.0 C (104.0 F)
2001
41.7 C (107.1 F)
2002
41.7 C (107.1 F)
2003
41.1 C (106.0 F)
2004
38.3 C (100.9 F)
2005
42.2 C (108.0 F)
2006
43.3 C (109.9 F)
2007
41.7 C (107.1 F)
Coldest night (TNn)
The coldest night of the year at San Luis Dam, 1963 to 2007. The record is -10.0 C (14.0 F) in 1990, marked on the chart; the median year is -3.3 C (26.1 F).
Coldest night (TNn) at San Luis Dam by year
Year
Coldest night (TNn)
1963
-6.1 C (21.0 F)
1964
-4.4 C (24.1 F)
1965
-5.0 C (23.0 F)
1966
-3.3 C (26.1 F)
1967
-3.3 C (26.1 F)
1968
-3.9 C (25.0 F)
1969
-1.1 C (30.0 F)
1970
-1.7 C (28.9 F)
1971
-2.8 C (27.0 F)
1972
-6.7 C (19.9 F)
1973
-3.9 C (25.0 F)
1974
-3.9 C (25.0 F)
1975
-4.4 C (24.1 F)
1976
-3.9 C (25.0 F)
1977
-1.1 C (30.0 F)
1978
-8.3 C (17.1 F)
1979
-5.6 C (21.9 F)
1980
-1.7 C (28.9 F)
1981
0.6 C (33.1 F)
1982
-3.9 C (25.0 F)
1983
-2.2 C (28.0 F)
1984
-2.2 C (28.0 F)
1985
-3.3 C (26.1 F)
1986
-0.6 C (30.9 F)
1987
-5.0 C (23.0 F)
1988
-3.9 C (25.0 F)
1989
-5.6 C (21.9 F)
1990
-10.0 C (14.0 F)
1991
-1.7 C (28.9 F)
1992
-1.7 C (28.9 F)
1993
-3.3 C (26.1 F)
1994
-3.9 C (25.0 F)
1995
0.6 C (33.1 F)
1996
0.6 C (33.1 F)
1997
-4.4 C (24.1 F)
1998
-6.7 C (19.9 F)
1999
-2.2 C (28.0 F)
2000
-1.1 C (30.0 F)
2001
-2.8 C (27.0 F)
2002
-3.3 C (26.1 F)
2003
0.0 C (32.0 F)
2004
-2.2 C (28.0 F)
2005
1.1 C (34.0 F)
2006
-3.9 C (25.0 F)
2007
-5.0 C (23.0 F)
Wettest day (Rx1day)
The wettest day of the year at San Luis Dam, 1963 to 2007. The record is 94.0 mm (3.7 in) in 1998, marked on the chart; the median year is 29.0 mm (1.1 in).
Wettest day (Rx1day) at San Luis Dam by year
Year
Wettest day (Rx1day)
1963
44.5 mm (1.8 in)
1964
29.0 mm (1.1 in)
1965
40.6 mm (1.6 in)
1966
32.3 mm (1.3 in)
1967
18.5 mm (0.7 in)
1968
14.5 mm (0.6 in)
1969
39.1 mm (1.5 in)
1970
37.1 mm (1.5 in)
1971
22.4 mm (0.9 in)
1972
37.1 mm (1.5 in)
1973
22.4 mm (0.9 in)
1974
39.4 mm (1.6 in)
1975
23.9 mm (0.9 in)
1976
43.4 mm (1.7 in)
1977
21.6 mm (0.9 in)
1978
39.6 mm (1.6 in)
1979
22.1 mm (0.9 in)
1980
29.2 mm (1.1 in)
1981
30.7 mm (1.2 in)
1982
21.6 mm (0.9 in)
1983
23.9 mm (0.9 in)
1984
20.3 mm (0.8 in)
1985
16.0 mm (0.6 in)
1986
27.2 mm (1.1 in)
1987
46.0 mm (1.8 in)
1988
20.6 mm (0.8 in)
1989
21.6 mm (0.9 in)
1990
29.5 mm (1.2 in)
1991
27.9 mm (1.1 in)
1992
16.3 mm (0.6 in)
1993
36.8 mm (1.4 in)
1994
24.9 mm (1.0 in)
1995
47.2 mm (1.9 in)
1996
36.8 mm (1.4 in)
1997
25.1 mm (1.0 in)
1998
94.0 mm (3.7 in)
1999
28.2 mm (1.1 in)
2000
29.5 mm (1.2 in)
2001
26.9 mm (1.1 in)
2002
34.3 mm (1.4 in)
2003
30.5 mm (1.2 in)
2004
22.4 mm (0.9 in)
2005
34.0 mm (1.3 in)
2006
32.0 mm (1.3 in)
2007
8.4 mm (0.33 in)
Wettest five days (Rx5day)
The wettest five days of the year at San Luis Dam, 1963 to 2007. The record is 133.6 mm (5.3 in) in 1998, marked on the chart; the median year is 51.1 mm (2.0 in).
Wettest five days (Rx5day) at San Luis Dam by year
Year
Wettest five days (Rx5day)
1963
94.1 mm (3.7 in)
1964
47.8 mm (1.9 in)
1965
91.5 mm (3.6 in)
1966
72.5 mm (2.9 in)
1967
44.9 mm (1.8 in)
1968
21.0 mm (0.8 in)
1969
68.8 mm (2.7 in)
1970
58.9 mm (2.3 in)
1971
39.2 mm (1.5 in)
1972
78.5 mm (3.1 in)
1973
47.4 mm (1.9 in)
1974
55.9 mm (2.2 in)
1975
37.6 mm (1.5 in)
1976
65.5 mm (2.6 in)
1977
40.6 mm (1.6 in)
1978
87.4 mm (3.4 in)
1979
46.3 mm (1.8 in)
1980
67.3 mm (2.6 in)
1981
62.5 mm (2.5 in)
1982
35.0 mm (1.4 in)
1983
45.7 mm (1.8 in)
1984
22.2 mm (0.9 in)
1985
35.8 mm (1.4 in)
1986
59.0 mm (2.3 in)
1987
56.9 mm (2.2 in)
1988
36.9 mm (1.5 in)
1989
21.6 mm (0.9 in)
1990
38.9 mm (1.5 in)
1991
96.4 mm (3.8 in)
1992
42.2 mm (1.7 in)
1993
63.5 mm (2.5 in)
1994
39.6 mm (1.6 in)
1995
87.4 mm (3.4 in)
1996
45.2 mm (1.8 in)
1997
49.9 mm (2.0 in)
1998
133.6 mm (5.3 in)
1999
31.0 mm (1.2 in)
2000
52.9 mm (2.1 in)
2001
54.0 mm (2.1 in)
2002
51.1 mm (2.0 in)
2003
41.7 mm (1.6 in)
2004
56.0 mm (2.2 in)
2005
61.5 mm (2.4 in)
2006
62.4 mm (2.5 in)
2007
23.2 mm (0.9 in)
Longest dry spell (CDD)
The longest dry spell of the year at San Luis Dam, 1963 to 2007. The record is 209 days in 1995, marked on the chart; the median year is 119 days.
Longest dry spell (CDD) at San Luis Dam by year
Year
Longest dry spell (CDD)
1963
93 days
1964
56 days
1965
100 days
1966
81 days
1967
122 days
1968
152 days
1969
89 days
1970
133 days
1971
140 days
1972
184 days
1973
175 days
1974
83 days
1975
80 days
1976
69 days
1977
100 days
1978
69 days
1979
85 days
1980
114 days
1981
174 days
1982
77 days
1983
112 days
1984
174 days
1985
139 days
1986
105 days
1987
143 days
1988
158 days
1989
175 days
1990
118 days
1991
90 days
1992
107 days
1993
127 days
1994
139 days
1995
209 days
1996
163 days
1997
119 days
1998
148 days
1999
188 days
2000
147 days
2001
156 days
2002
169 days
2003
90 days
2004
114 days
2005
71 days
2006
80 days
2007
131 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
35 years with a frost
Across 35 years with a frost, the median last spring frost at San Luis Dam falls on 5 February and the median first autumn frost on 9 December, which leaves a median of 305 days between them.
Fitted over all years, the growing season changes by -2.4 days per decade at this station.
Frost dates and growing season at San Luis Dam
Measure
Median, all years
Earliest period
Recent period (1969 to 2006)
Recent against earliest
Fitted trend
Last spring frost
5 February
n/a
7 February
n/a
0.0 days per decade
First autumn frost
9 December
n/a
7 December
n/a
-2.4 days per decade
Growing days
305 days
n/a
304 days
n/a
-2.4 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
44 years, 1963 to 2006
A day with at least 28.3 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 73.6 mm (2.9 in) of rain is expected about once in 100 years.
Rainfall return levels at San Luis Dam: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
28.3 mm (1.1 in)
5 years
38.3 mm (1.5 in)
10 years
45.7 mm (1.8 in)
25 years
56.0 mm (2.2 in)
50 years
64.5 mm (2.5 in)
Longer than the 44 years of record
100 years
73.6 mm (2.9 in)
Longer than the 44 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, 44 years of values from 1963 to 2006.
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: 94.0 mm (3.7 in) in 1998; 47.2 mm (1.9 in) in 1995; 46.0 mm (1.8 in) in 1987.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of San Luis Dam, at 1969. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1969 ran 0.2 C (0.4 F) lower than in the years before (possible change).
Suspected changes in the annual mean temperature at San Luis Dam, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1969
-0.2
-0.4
possible
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for San Luis Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for San Luis Dam 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.