Record envelope, standing records and threshold days for La Mesa (USC00044735), California, United States, with 108 years of record.
Key Facts for La Mesa
La Mesa (USC00044735) is a weather station in California, United States at 32.77 latitude and -117.02 longitude, 162 m (530 ft) above sea level.
The station reports from 1899 to 2006, 108 years of record.
1,464 records set at La Mesa still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
La Mesa set a daily record low minimum temperature of 0.0 C (32.0 F) on 28 February 2006.
About the Station
Location: California, United States, 32.77 latitude, -117.02 longitude.
Elevation: 162 m (530 ft).
Period of record: 1899 to 2006, 108 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 La Mesa. 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 La Mesa, 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)
-3.9 C (25.0 F)
n/a
n/a
Feb
33.3 C (91.9 F)
-2.8 C (27.0 F)
n/a
n/a
Mar
35.6 C (96.1 F)
-2.2 C (28.0 F)
n/a
n/a
Apr
40.6 C (105.1 F)
0.6 C (33.1 F)
n/a
n/a
May
37.8 C (100.0 F)
3.3 C (37.9 F)
n/a
n/a
Jun
41.7 C (107.1 F)
6.1 C (43.0 F)
n/a
n/a
Jul
41.1 C (106.0 F)
7.8 C (46.0 F)
n/a
n/a
Aug
41.1 C (106.0 F)
8.9 C (48.0 F)
n/a
n/a
Sep
42.8 C (109.0 F)
6.7 C (44.1 F)
n/a
n/a
Oct
40.6 C (105.1 F)
-1.1 C (30.0 F)
n/a
n/a
Nov
36.1 C (97.0 F)
-1.1 C (30.0 F)
n/a
n/a
Dec
37.8 C (100.0 F)
-1.7 C (28.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at La Mesa still stand. 1948 holds the most, with 79.
Standing records at La Mesa by the year they were set
Year set
Standing records
1934
23
1935
30
1936
25
1937
19
1938
21
1939
24
1940
28
1941
35
1942
61
1943
19
1944
39
1945
42
1946
32
1947
31
1948
79
1949
55
1950
24
1951
21
1952
33
1953
22
1954
14
1955
28
1956
19
1957
20
1958
19
1959
17
1960
12
1961
12
1962
10
1963
19
1964
16
1965
23
1966
12
1967
12
1968
11
1969
13
1970
5
1971
30
1972
11
1973
9
1974
5
1975
10
1976
11
1977
15
1978
28
1979
23
1980
22
1981
15
1982
9
1983
12
1984
25
1985
20
1986
21
1987
19
1988
20
1989
21
1990
20
1991
10
1992
37
1993
17
1994
11
1995
14
1996
16
1997
23
1998
10
1999
6
2000
7
2001
9
2002
6
2003
6
2004
15
2005
3
2006
3
All-Time Record Progression
2 new records
2 all-time records were set at La Mesa between 31 January 1979 and 3 September 1988. Each dot is a new record.
When La Mesa set new all-time records
Date
Kind
Detail
1979-01-31
Record daily precipitation
Record daily precipitation 108.0 mm (4.3 in)
1988-09-03
Record high maximum temperature
Record high maximum temperature 42.8 C (109.0 F)
Wettest Day of Each Month
Jan: 108.0 mm (4.3 in)
The wettest day on record for each calendar month at La Mesa. The most was 108.0 mm (4.3 in) on 31 January 1979.
Record daily precipitation for each month at La Mesa
Month
Record daily precipitation (mm)
Date
Jan
108.0 mm (4.3 in)
31 January 1979
Feb
101.6 mm (4.0 in)
7 February 1937
Mar
50.8 mm (2.0 in)
3 March 1938
Apr
50.3 mm (2.0 in)
1 April 1941
May
40.9 mm (1.6 in)
9 May 1977
Jun
21.8 mm (0.9 in)
9 June 1944
Jul
23.4 mm (0.9 in)
25 July 1902
Aug
41.9 mm (1.6 in)
17 August 1977
Sep
33.0 mm (1.3 in)
25 September 1986
Oct
50.3 mm (2.0 in)
27 October 2004
Nov
60.7 mm (2.4 in)
11 November 1985
Dec
93.7 mm (3.7 in)
24 December 1940
Period of Record Coverage
1934 to 2006
Complete yearUnder 90 percent of days
73 years of record at La Mesa, 1934 to 2006. 25 years have data for under 90 percent of days and are left out of rankings: 1934, 1946, 1966, 1980, 1984, 1985, 1986, 1987 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 53 complete years at La Mesa, 1935 to 2000. Blue stripes are years cooler than the station's own mean of 17.4 C (63.3 F); red stripes are warmer. The coolest year was 1948, at 15.0 C (59.0 F), and the warmest was 1984, at 19.1 C (66.3 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at La Mesa as warming stripes, 1935 to 2000
Year
Annual mean temperature
Difference from the station mean
1935
17.6 C
+0.19 C
1936
18.7 C
+1.33 C
1937
18.2 C
+0.76 C
1938
18.6 C
+1.20 C
1939
17.7 C
+0.25 C
1940
17.4 C
+0.00 C
1941
16.6 C
-0.82 C
1942
15.7 C
-1.74 C
1943
17.0 C
-0.45 C
1944
15.5 C
-1.89 C
1945
16.0 C
-1.44 C
1947
16.5 C
-0.96 C
1948
15.0 C
-2.39 C
1949
15.8 C
-1.66 C
1950
16.2 C
-1.25 C
1951
16.1 C
-1.32 C
1952
15.9 C
-1.50 C
1953
16.4 C
-0.97 C
1954
16.8 C
-0.61 C
1955
16.4 C
-0.97 C
1956
17.0 C
-0.39 C
1957
17.4 C
-0.05 C
1958
18.2 C
+0.82 C
1959
18.4 C
+0.94 C
1960
17.6 C
+0.17 C
1961
17.4 C
+0.00 C
1962
16.9 C
-0.54 C
1963
17.6 C
+0.16 C
1964
16.8 C
-0.59 C
1965
17.1 C
-0.33 C
1967
17.8 C
+0.41 C
1968
17.6 C
+0.19 C
1969
17.7 C
+0.28 C
1970
17.9 C
+0.44 C
1971
16.9 C
-0.51 C
1972
17.7 C
+0.29 C
1973
17.2 C
-0.20 C
1974
17.7 C
+0.31 C
1975
16.9 C
-0.54 C
1976
18.2 C
+0.77 C
1977
18.2 C
+0.83 C
1978
18.4 C
+0.96 C
1979
18.1 C
+0.65 C
1981
18.9 C
+1.49 C
1982
17.5 C
+0.06 C
1983
18.5 C
+1.08 C
1984
19.1 C
+1.65 C
1986
18.6 C
+1.17 C
1987
18.0 C
+0.55 C
1988
18.5 C
+1.08 C
1989
18.5 C
+1.09 C
1994
18.2 C
+0.80 C
2000
18.6 C
+1.16 C
The annual mean temperature here has risen by 0.3 C (0.2 to 0.4) per decade over 1935 to 2000. In Fahrenheit: 0.5 F (0.3 to 0.8) per decade. The slope is a straight line fitted to 53 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at La Mesa
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 0.8) per decade
1935 to 2000
53
Rise
Mean daily maximum
0.13 C (-0.05 to 0.31) per decade
0.2 F (-0.1 to 0.6) per decade
1935 to 2000
53
Not clearly different from zero
Mean daily minimum
0.5 C (0.3 to 0.6) per decade
0.9 F (0.6 to 1.1) per decade
1935 to 2000
53
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
1899 to 2006
Yearly extremes at La Mesa: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
42.8 C (109.0 F)
1988
38.3 C (100.9 F)
73
Coldest night (TNn)
-3.9 C (25.0 F)
1948
1.1 C (34.0 F)
73
Wettest day (Rx1day)
108.0 mm (4.3 in)
1979
41.7 mm (1.6 in)
79
Wettest five days (Rx5day)
145.8 mm (5.7 in)
1983
76.2 mm (3.0 in)
79
Longest dry spell (CDD)
200 days
1973
112 days
79
Hottest day (TXx)
The hottest day of the year at La Mesa, 1899 to 2006. The record is 42.8 C (109.0 F) in 1988, marked on the chart; the median year is 38.3 C (100.9 F).
Hottest day (TXx) at La Mesa by year
Year
Hottest day (TXx)
1899
n/a
1900
n/a
1901
n/a
1902
n/a
1903
n/a
1904
n/a
1934
41.1 C (106.0 F)
1935
41.1 C (106.0 F)
1936
41.1 C (106.0 F)
1937
41.7 C (107.1 F)
1938
38.9 C (102.0 F)
1939
40.0 C (104.0 F)
1940
38.9 C (102.0 F)
1941
35.0 C (95.0 F)
1942
36.7 C (98.1 F)
1943
37.2 C (99.0 F)
1944
40.6 C (105.1 F)
1945
37.8 C (100.0 F)
1946
36.7 C (98.1 F)
1947
38.9 C (102.0 F)
1948
37.2 C (99.0 F)
1949
37.8 C (100.0 F)
1950
37.8 C (100.0 F)
1951
36.7 C (98.1 F)
1952
35.0 C (95.0 F)
1953
37.8 C (100.0 F)
1954
36.1 C (97.0 F)
1955
42.2 C (108.0 F)
1956
40.6 C (105.1 F)
1957
40.0 C (104.0 F)
1958
40.6 C (105.1 F)
1959
36.7 C (98.1 F)
1960
38.3 C (100.9 F)
1961
39.4 C (102.9 F)
1962
36.1 C (97.0 F)
1963
41.7 C (107.1 F)
1964
35.6 C (96.1 F)
1965
38.3 C (100.9 F)
1966
36.1 C (97.0 F)
1967
40.0 C (104.0 F)
1968
38.3 C (100.9 F)
1969
41.1 C (106.0 F)
1970
36.1 C (97.0 F)
1971
40.0 C (104.0 F)
1972
38.9 C (102.0 F)
1973
37.8 C (100.0 F)
1974
36.7 C (98.1 F)
1975
39.4 C (102.9 F)
1976
40.6 C (105.1 F)
1977
38.3 C (100.9 F)
1978
41.1 C (106.0 F)
1979
40.0 C (104.0 F)
1980
38.9 C (102.0 F)
1981
39.4 C (102.9 F)
1982
40.0 C (104.0 F)
1983
38.3 C (100.9 F)
1984
40.6 C (105.1 F)
1985
41.1 C (106.0 F)
1986
36.7 C (98.1 F)
1987
40.6 C (105.1 F)
1988
42.8 C (109.0 F)
1989
40.6 C (105.1 F)
1990
39.4 C (102.9 F)
1991
38.9 C (102.0 F)
1992
39.4 C (102.9 F)
1993
36.7 C (98.1 F)
1994
38.9 C (102.0 F)
1995
36.7 C (98.1 F)
1996
37.2 C (99.0 F)
1997
36.7 C (98.1 F)
1998
40.0 C (104.0 F)
1999
38.3 C (100.9 F)
2000
37.8 C (100.0 F)
2001
36.7 C (98.1 F)
2002
37.2 C (99.0 F)
2003
36.7 C (98.1 F)
2004
37.8 C (100.0 F)
2005
35.6 C (96.1 F)
2006
29.4 C (84.9 F)
Coldest night (TNn)
The coldest night of the year at La Mesa, 1899 to 2006. The record is -3.9 C (25.0 F) in 1948, marked on the chart; the median year is 1.1 C (34.0 F).
Coldest night (TNn) at La Mesa by year
Year
Coldest night (TNn)
1899
n/a
1900
n/a
1901
n/a
1902
n/a
1903
n/a
1904
n/a
1934
3.3 C (37.9 F)
1935
0.6 C (33.1 F)
1936
2.8 C (37.0 F)
1937
-2.8 C (27.0 F)
1938
1.7 C (35.1 F)
1939
-1.1 C (30.0 F)
1940
0.0 C (32.0 F)
1941
-0.6 C (30.9 F)
1942
-2.8 C (27.0 F)
1943
-0.6 C (30.9 F)
1944
-0.6 C (30.9 F)
1945
-2.2 C (28.0 F)
1946
-2.2 C (28.0 F)
1947
-3.3 C (26.1 F)
1948
-3.9 C (25.0 F)
1949
-3.3 C (26.1 F)
1950
0.0 C (32.0 F)
1951
0.6 C (33.1 F)
1952
-0.6 C (30.9 F)
1953
-0.6 C (30.9 F)
1954
-0.6 C (30.9 F)
1955
0.6 C (33.1 F)
1956
0.6 C (33.1 F)
1957
2.8 C (37.0 F)
1958
1.7 C (35.1 F)
1959
3.3 C (37.9 F)
1960
0.0 C (32.0 F)
1961
3.3 C (37.9 F)
1962
1.1 C (34.0 F)
1963
-2.8 C (27.0 F)
1964
2.2 C (36.0 F)
1965
1.1 C (34.0 F)
1966
1.1 C (34.0 F)
1967
1.1 C (34.0 F)
1968
-1.7 C (28.9 F)
1969
0.0 C (32.0 F)
1970
1.1 C (34.0 F)
1971
-2.2 C (28.0 F)
1972
-1.1 C (30.0 F)
1973
1.1 C (34.0 F)
1974
-0.6 C (30.9 F)
1975
1.7 C (35.1 F)
1976
0.0 C (32.0 F)
1977
3.3 C (37.9 F)
1978
-1.7 C (28.9 F)
1979
0.6 C (33.1 F)
1980
3.3 C (37.9 F)
1981
2.8 C (37.0 F)
1982
-1.1 C (30.0 F)
1983
1.7 C (35.1 F)
1984
2.2 C (36.0 F)
1985
1.7 C (35.1 F)
1986
3.3 C (37.9 F)
1987
-1.1 C (30.0 F)
1988
1.7 C (35.1 F)
1989
1.7 C (35.1 F)
1990
-0.6 C (30.9 F)
1991
2.8 C (37.0 F)
1992
2.2 C (36.0 F)
1993
2.2 C (36.0 F)
1994
2.8 C (37.0 F)
1995
5.0 C (41.0 F)
1996
3.9 C (39.0 F)
1997
1.7 C (35.1 F)
1998
1.7 C (35.1 F)
1999
2.8 C (37.0 F)
2000
3.3 C (37.9 F)
2001
2.8 C (37.0 F)
2002
1.7 C (35.1 F)
2003
1.7 C (35.1 F)
2004
-1.1 C (30.0 F)
2005
4.4 C (39.9 F)
2006
0.0 C (32.0 F)
Wettest day (Rx1day)
The wettest day of the year at La Mesa, 1899 to 2006. The record is 108.0 mm (4.3 in) in 1979, marked on the chart; the median year is 41.7 mm (1.6 in).
Wettest day (Rx1day) at La Mesa by year
Year
Wettest day (Rx1day)
1899
45.7 mm (1.8 in)
1900
31.8 mm (1.3 in)
1901
78.0 mm (3.1 in)
1902
64.8 mm (2.6 in)
1903
29.2 mm (1.1 in)
1904
34.3 mm (1.4 in)
1934
25.4 mm (1.0 in)
1935
50.8 mm (2.0 in)
1936
49.3 mm (1.9 in)
1937
101.6 mm (4.0 in)
1938
52.6 mm (2.1 in)
1939
41.9 mm (1.6 in)
1940
93.7 mm (3.7 in)
1941
50.3 mm (2.0 in)
1942
48.0 mm (1.9 in)
1943
52.8 mm (2.1 in)
1944
58.9 mm (2.3 in)
1945
63.2 mm (2.5 in)
1946
30.7 mm (1.2 in)
1947
56.1 mm (2.2 in)
1948
25.7 mm (1.0 in)
1949
31.8 mm (1.3 in)
1950
35.6 mm (1.4 in)
1951
63.5 mm (2.5 in)
1952
40.6 mm (1.6 in)
1953
19.1 mm (0.8 in)
1954
42.4 mm (1.7 in)
1955
27.9 mm (1.1 in)
1956
39.9 mm (1.6 in)
1957
28.7 mm (1.1 in)
1958
51.8 mm (2.0 in)
1959
22.1 mm (0.9 in)
1960
26.9 mm (1.1 in)
1961
22.1 mm (0.9 in)
1962
31.5 mm (1.2 in)
1963
34.8 mm (1.4 in)
1964
34.8 mm (1.4 in)
1965
53.6 mm (2.1 in)
1966
69.1 mm (2.7 in)
1967
43.2 mm (1.7 in)
1968
30.0 mm (1.2 in)
1969
65.0 mm (2.6 in)
1970
34.5 mm (1.4 in)
1971
23.9 mm (0.9 in)
1972
26.9 mm (1.1 in)
1973
29.0 mm (1.1 in)
1974
41.7 mm (1.6 in)
1975
50.8 mm (2.0 in)
1976
32.0 mm (1.3 in)
1977
41.9 mm (1.6 in)
1978
70.1 mm (2.8 in)
1979
108.0 mm (4.3 in)
1980
60.5 mm (2.4 in)
1981
38.1 mm (1.5 in)
1982
33.5 mm (1.3 in)
1983
47.2 mm (1.9 in)
1984
30.0 mm (1.2 in)
1985
60.7 mm (2.4 in)
1986
53.1 mm (2.1 in)
1987
35.6 mm (1.4 in)
1988
44.7 mm (1.8 in)
1989
15.0 mm (0.6 in)
1990
26.4 mm (1.0 in)
1991
50.3 mm (2.0 in)
1992
49.0 mm (1.9 in)
1993
53.6 mm (2.1 in)
1994
42.4 mm (1.7 in)
1995
59.9 mm (2.4 in)
1996
48.3 mm (1.9 in)
1997
32.5 mm (1.3 in)
1998
47.5 mm (1.9 in)
1999
19.6 mm (0.8 in)
2000
30.5 mm (1.2 in)
2001
38.1 mm (1.5 in)
2002
22.9 mm (0.9 in)
2003
34.0 mm (1.3 in)
2004
50.3 mm (2.0 in)
2005
31.8 mm (1.3 in)
2006
0.0 mm (0.00 in)
Wettest five days (Rx5day)
The wettest five days of the year at La Mesa, 1899 to 2006. The record is 145.8 mm (5.7 in) in 1983, marked on the chart; the median year is 76.2 mm (3.0 in).
Wettest five days (Rx5day) at La Mesa by year
Year
Wettest five days (Rx5day)
1899
62.7 mm (2.5 in)
1900
38.4 mm (1.5 in)
1901
127.8 mm (5.0 in)
1902
78.6 mm (3.1 in)
1903
76.2 mm (3.0 in)
1904
45.7 mm (1.8 in)
1934
58.6 mm (2.3 in)
1935
105.1 mm (4.1 in)
1936
99.4 mm (3.9 in)
1937
113.0 mm (4.4 in)
1938
144.0 mm (5.7 in)
1939
76.2 mm (3.0 in)
1940
117.8 mm (4.6 in)
1941
89.4 mm (3.5 in)
1942
53.8 mm (2.1 in)
1943
111.2 mm (4.4 in)
1944
116.0 mm (4.6 in)
1945
126.3 mm (5.0 in)
1946
47.3 mm (1.9 in)
1947
114.0 mm (4.5 in)
1948
36.1 mm (1.4 in)
1949
78.3 mm (3.1 in)
1950
35.6 mm (1.4 in)
1951
100.3 mm (3.9 in)
1952
101.1 mm (4.0 in)
1953
23.4 mm (0.9 in)
1954
125.4 mm (4.9 in)
1955
54.5 mm (2.1 in)
1956
57.5 mm (2.3 in)
1957
72.7 mm (2.9 in)
1958
63.8 mm (2.5 in)
1959
46.5 mm (1.8 in)
1960
54.2 mm (2.1 in)
1961
29.5 mm (1.2 in)
1962
89.7 mm (3.5 in)
1963
42.4 mm (1.7 in)
1964
41.4 mm (1.6 in)
1965
92.2 mm (3.6 in)
1966
90.7 mm (3.6 in)
1967
65.3 mm (2.6 in)
1968
31.0 mm (1.2 in)
1969
84.8 mm (3.3 in)
1970
83.0 mm (3.3 in)
1971
47.9 mm (1.9 in)
1972
53.8 mm (2.1 in)
1973
51.4 mm (2.0 in)
1974
94.9 mm (3.7 in)
1975
85.6 mm (3.4 in)
1976
112.3 mm (4.4 in)
1977
59.2 mm (2.3 in)
1978
105.4 mm (4.1 in)
1979
124.8 mm (4.9 in)
1980
142.2 mm (5.6 in)
1981
82.9 mm (3.3 in)
1982
106.1 mm (4.2 in)
1983
145.8 mm (5.7 in)
1984
65.8 mm (2.6 in)
1985
84.8 mm (3.3 in)
1986
57.7 mm (2.3 in)
1987
56.8 mm (2.2 in)
1988
121.1 mm (4.8 in)
1989
21.4 mm (0.8 in)
1990
50.3 mm (2.0 in)
1991
92.2 mm (3.6 in)
1992
65.3 mm (2.6 in)
1993
143.5 mm (5.6 in)
1994
49.1 mm (1.9 in)
1995
77.2 mm (3.0 in)
1996
48.3 mm (1.9 in)
1997
61.7 mm (2.4 in)
1998
76.7 mm (3.0 in)
1999
42.4 mm (1.7 in)
2000
79.6 mm (3.1 in)
2001
61.7 mm (2.4 in)
2002
40.4 mm (1.6 in)
2003
54.0 mm (2.1 in)
2004
74.2 mm (2.9 in)
2005
77.6 mm (3.1 in)
2006
0.0 mm (0.00 in)
Longest dry spell (CDD)
The longest dry spell of the year at La Mesa, 1899 to 2006. The record is 200 days in 1973, marked on the chart; the median year is 112 days.
Longest dry spell (CDD) at La Mesa by year
Year
Longest dry spell (CDD)
1899
90 days
1900
82 days
1901
33 days
1902
25 days
1903
25 days
1904
9 days
1934
75 days
1935
116 days
1936
68 days
1937
165 days
1938
76 days
1939
134 days
1940
78 days
1941
119 days
1942
165 days
1943
122 days
1944
144 days
1945
73 days
1946
50 days
1947
108 days
1948
171 days
1949
90 days
1950
127 days
1951
119 days
1952
137 days
1953
96 days
1954
115 days
1955
172 days
1956
136 days
1957
122 days
1958
135 days
1959
157 days
1960
137 days
1961
128 days
1962
184 days
1963
83 days
1964
160 days
1965
56 days
1966
131 days
1967
79 days
1968
109 days
1969
95 days
1970
158 days
1971
123 days
1972
65 days
1973
200 days
1974
159 days
1975
110 days
1976
66 days
1977
83 days
1978
126 days
1979
91 days
1980
82 days
1981
126 days
1982
85 days
1983
104 days
1984
112 days
1985
109 days
1986
53 days
1987
78 days
1988
143 days
1989
129 days
1990
162 days
1991
98 days
1992
133 days
1993
116 days
1994
159 days
1995
136 days
1996
107 days
1997
62 days
1998
76 days
1999
153 days
2000
95 days
2001
169 days
2002
131 days
2003
140 days
2004
106 days
2005
75 days
2006
57 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.
Rainfall Return Levels
64 years, 1899 to 2002
A day with at least 41.1 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 95.4 mm (3.8 in) of rain is expected about once in 100 years.
Rainfall return levels at La Mesa: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
41.1 mm (1.6 in)
5 years
56.4 mm (2.2 in)
10 years
66.2 mm (2.6 in)
25 years
78.3 mm (3.1 in)
50 years
87.0 mm (3.4 in)
100 years
95.4 mm (3.8 in)
Longer than the 64 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, 64 years of values from 1899 to 2002.
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: 108.0 mm (4.3 in) in 1979; 101.6 mm (4.0 in) in 1937; 70.1 mm (2.8 in) in 1978.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of La Mesa, at 1954. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1954 ran 0.5 C (0.8 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at La Mesa, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1954
+0.5
+0.8
likely
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 La Mesa standing records by year: CSV or JSON. Field meanings are on the data page.
Data for La Mesa 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.