Record envelope, standing records and threshold days for Porterville (USC00047077), California, United States, with 103 years of record.
Key Facts for Porterville
Porterville (USC00047077) is a weather station in California, United States at 36.07 latitude and -119.02 longitude, 120 m (393 ft) above sea level.
The station reports from 1902 to 2004, 103 years of record.
1,464 records set at Porterville still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Porterville set a daily record high maximum temperature of 38.9 C (102.0 F) on 5 May 2004.
About the Station
Location: California, United States, 36.07 latitude, -119.02 longitude.
Elevation: 120 m (393 ft).
Period of record: 1902 to 2004, 103 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 Porterville. 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 Porterville, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
30.0 C (86.0 F)
-7.8 C (18.0 F)
n/a
n/a
Feb
29.4 C (84.9 F)
-6.7 C (19.9 F)
n/a
n/a
Mar
32.8 C (91.0 F)
-2.2 C (28.0 F)
n/a
n/a
Apr
38.3 C (100.9 F)
-3.3 C (26.1 F)
n/a
n/a
May
42.8 C (109.0 F)
0.6 C (33.1 F)
n/a
n/a
Jun
44.4 C (111.9 F)
-1.1 C (30.0 F)
n/a
n/a
Jul
45.6 C (114.1 F)
6.7 C (44.1 F)
n/a
n/a
Aug
45.0 C (113.0 F)
6.1 C (43.0 F)
n/a
n/a
Sep
44.4 C (111.9 F)
2.8 C (37.0 F)
n/a
n/a
Oct
39.4 C (102.9 F)
-1.1 C (30.0 F)
n/a
n/a
Nov
35.0 C (95.0 F)
-5.6 C (21.9 F)
n/a
n/a
Dec
30.0 C (86.0 F)
-8.9 C (16.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Porterville still stand. 1913 holds the most, with 42.
Standing records at Porterville by the year they were set
Year set
Standing records
1902
9
1903
28
1904
20
1905
22
1906
11
1907
16
1908
25
1909
14
1910
21
1911
27
1912
20
1913
42
1914
5
1915
11
1916
23
1917
9
1918
17
1919
19
1920
41
1921
22
1922
19
1923
15
1924
15
1925
21
1926
22
1927
16
1928
11
1929
23
1930
14
1931
18
1932
19
1933
33
1934
9
1935
18
1936
12
1937
16
1938
11
1939
12
1940
9
1941
6
1942
7
1943
6
1944
9
1945
9
1946
10
1947
19
1948
11
1949
16
1950
26
1951
7
1952
9
1953
20
1954
12
1955
12
1956
9
1957
10
1958
7
1959
6
1960
12
1961
19
1962
17
1963
25
1964
18
1965
13
1966
15
1967
10
1968
14
1969
7
1970
7
1971
11
1972
22
1973
11
1974
9
1975
5
1976
18
1977
14
1978
15
1979
7
1980
11
1981
10
1982
13
1983
7
1984
7
1985
9
1986
15
1987
19
1988
5
1989
21
1990
14
1991
11
1992
2
1993
5
1994
1
1995
10
1996
14
1997
15
1998
18
1999
7
2000
16
2001
11
2002
9
2003
10
2004
9
All-Time Record Progression
4 new records
4 all-time records were set at Porterville between 11 January 1940 and 25 January 1999. Each dot is a new record.
When Porterville set new all-time records
Date
Kind
Detail
1940-01-11
Record daily precipitation
Record daily precipitation 68.1 mm (2.7 in)
1969-02-25
Record daily precipitation
Record daily precipitation 69.1 mm (2.7 in)
1990-12-23
Record low minimum temperature
Record low minimum temperature -8.9 C (16.0 F)
1999-01-25
Record snow depth
Record snow depth 7.6 cm (3.0 in)
Wettest Day of Each Month
Feb: 69.1 mm (2.7 in)
The wettest day on record for each calendar month at Porterville. The most was 69.1 mm (2.7 in) on 25 February 1969.
Record daily precipitation for each month at Porterville
Month
Record daily precipitation (mm)
Date
Jan
68.1 mm (2.7 in)
11 January 1940
Feb
69.1 mm (2.7 in)
25 February 1969
Mar
42.7 mm (1.7 in)
3 March 1938
Apr
38.1 mm (1.5 in)
28 April 1906
May
46.5 mm (1.8 in)
27 May 1971
Jun
20.3 mm (0.8 in)
5 June 1993
Jul
7.6 mm (0.30 in)
21 July 1913
Aug
6.4 mm (0.25 in)
18 August 1977
Sep
39.4 mm (1.6 in)
30 September 1976
Oct
54.1 mm (2.1 in)
19 October 1972
Nov
43.9 mm (1.7 in)
12 November 1944
Dec
59.4 mm (2.3 in)
6 December 1966
Period of Record Coverage
1902 to 2004
Complete yearUnder 90 percent of days
103 years of record at Porterville, 1902 to 2004. 7 years have data for under 90 percent of days and are left out of rankings: 1902, 1903, 1905, 1906, 1915, 1917, 2004.
Cooler than the station meanWarmer than the station mean
One stripe for each of 93 complete years at Porterville, 1907 to 2002. Blue stripes are years cooler than the station's own mean of 17.6 C (63.7 F); red stripes are warmer. The coolest year was 1948, at 16.1 C (60.9 F), and the warmest was 1996, at 19.3 C (66.7 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Porterville as warming stripes, 1907 to 2002
Year
Annual mean temperature
Difference from the station mean
1907
17.2 C
-0.37 C
1908
17.3 C
-0.34 C
1909
17.1 C
-0.48 C
1910
18.3 C
+0.66 C
1911
18.0 C
+0.41 C
1912
17.8 C
+0.17 C
1913
18.2 C
+0.62 C
1914
17.9 C
+0.35 C
1918
17.1 C
-0.50 C
1919
17.1 C
-0.51 C
1920
16.2 C
-1.41 C
1921
17.5 C
-0.10 C
1922
16.8 C
-0.80 C
1923
16.5 C
-1.05 C
1924
17.1 C
-0.46 C
1925
17.0 C
-0.62 C
1926
18.8 C
+1.16 C
1927
17.0 C
-0.61 C
1928
17.2 C
-0.37 C
1929
16.8 C
-0.84 C
1930
16.6 C
-0.99 C
1931
17.7 C
+0.08 C
1932
17.2 C
-0.35 C
1933
16.9 C
-0.67 C
1934
18.1 C
+0.52 C
1935
17.1 C
-0.50 C
1936
18.2 C
+0.62 C
1937
17.6 C
+0.03 C
1938
17.3 C
-0.27 C
1939
18.1 C
+0.46 C
1940
18.2 C
+0.60 C
1941
17.3 C
-0.26 C
1942
16.9 C
-0.70 C
1943
17.3 C
-0.25 C
1944
16.8 C
-0.78 C
1945
17.3 C
-0.33 C
1946
16.8 C
-0.83 C
1947
17.0 C
-0.59 C
1948
16.1 C
-1.54 C
1949
16.8 C
-0.78 C
1950
17.9 C
+0.30 C
1951
17.3 C
-0.34 C
1952
17.0 C
-0.61 C
1953
16.6 C
-1.04 C
1954
16.9 C
-0.68 C
1955
16.5 C
-1.06 C
1956
17.1 C
-0.49 C
1957
17.4 C
-0.21 C
1958
18.3 C
+0.70 C
1959
18.3 C
+0.71 C
1960
17.7 C
+0.14 C
1961
17.6 C
0.00 C
1962
17.1 C
-0.47 C
1963
16.8 C
-0.80 C
1964
16.8 C
-0.79 C
1965
17.0 C
-0.59 C
1966
17.9 C
+0.30 C
1967
17.4 C
-0.16 C
1968
17.4 C
-0.23 C
1969
17.4 C
-0.17 C
1970
17.9 C
+0.31 C
1971
16.8 C
-0.77 C
1972
17.3 C
-0.33 C
1973
17.9 C
+0.35 C
1974
17.8 C
+0.23 C
1975
17.2 C
-0.38 C
1976
17.4 C
-0.21 C
1977
17.6 C
+0.02 C
1978
17.7 C
+0.10 C
1979
18.2 C
+0.62 C
1980
18.1 C
+0.54 C
1981
18.8 C
+1.18 C
1982
17.2 C
-0.40 C
1983
18.0 C
+0.38 C
1984
18.3 C
+0.71 C
1985
17.8 C
+0.20 C
1986
18.7 C
+1.12 C
1987
18.3 C
+0.74 C
1988
18.4 C
+0.83 C
1989
18.0 C
+0.42 C
1990
18.1 C
+0.51 C
1991
18.2 C
+0.62 C
1992
18.3 C
+0.75 C
1993
17.7 C
+0.11 C
1994
17.9 C
+0.32 C
1995
19.1 C
+1.50 C
1996
19.3 C
+1.71 C
1997
19.2 C
+1.57 C
1998
17.8 C
+0.23 C
1999
18.1 C
+0.46 C
2000
18.8 C
+1.23 C
2001
19.1 C
+1.52 C
2002
18.6 C
+1.00 C
The annual mean temperature here has risen by 0.1 C (0.1 to 0.2) per decade over 1907 to 2002. In Fahrenheit: 0.2 F (0.1 to 0.3) per decade. The slope is a straight line fitted to 93 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Porterville
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.1 C (0.1 to 0.2) per decade
0.2 F (0.1 to 0.3) per decade
1907 to 2002
93
Rise
Mean daily maximum
0.01 C (-0.05 to 0.07) per decade
0.02 F (-0.08 to 0.12) per decade
1907 to 2002
93
Not clearly different from zero
Mean daily minimum
0.2 C (0.2 to 0.3) per decade
0.4 F (0.3 to 0.5) per decade
1907 to 2002
93
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
1902 to 2004
Yearly extremes at Porterville: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.6 C (114.1 F)
1905
42.8 C (109.0 F)
103
Coldest night (TNn)
-8.9 C (16.0 F)
1990
-3.9 C (25.0 F)
103
Wettest day (Rx1day)
69.1 mm (2.7 in)
1969
29.5 mm (1.2 in)
103
Wettest five days (Rx5day)
140.1 mm (5.5 in)
1966
47.5 mm (1.9 in)
103
Longest dry spell (CDD)
216 days
1914
122 days
103
Hottest day (TXx)
The hottest day of the year at Porterville, 1902 to 2004. The record is 45.6 C (114.1 F) in 1905, marked on the chart; the median year is 42.8 C (109.0 F).
Hottest day (TXx) at Porterville by year
Year
Hottest day (TXx)
1902
43.9 C (111.0 F)
1903
41.7 C (107.1 F)
1904
44.4 C (111.9 F)
1905
45.6 C (114.1 F)
1906
42.8 C (109.0 F)
1907
39.4 C (102.9 F)
1908
45.6 C (114.1 F)
1909
41.1 C (106.0 F)
1910
43.9 C (111.0 F)
1911
43.3 C (109.9 F)
1912
45.0 C (113.0 F)
1913
45.6 C (114.1 F)
1914
41.7 C (107.1 F)
1915
42.2 C (108.0 F)
1916
41.7 C (107.1 F)
1917
41.7 C (107.1 F)
1918
42.2 C (108.0 F)
1919
42.8 C (109.0 F)
1920
43.9 C (111.0 F)
1921
44.4 C (111.9 F)
1922
42.8 C (109.0 F)
1923
42.8 C (109.0 F)
1924
43.3 C (109.9 F)
1925
45.6 C (114.1 F)
1926
45.6 C (114.1 F)
1927
42.2 C (108.0 F)
1928
42.8 C (109.0 F)
1929
44.4 C (111.9 F)
1930
41.7 C (107.1 F)
1931
45.0 C (113.0 F)
1932
43.3 C (109.9 F)
1933
45.0 C (113.0 F)
1934
43.3 C (109.9 F)
1935
43.9 C (111.0 F)
1936
43.9 C (111.0 F)
1937
43.3 C (109.9 F)
1938
43.9 C (111.0 F)
1939
42.8 C (109.0 F)
1940
43.3 C (109.9 F)
1941
42.8 C (109.0 F)
1942
42.8 C (109.0 F)
1943
40.0 C (104.0 F)
1944
41.7 C (107.1 F)
1945
41.7 C (107.1 F)
1946
41.1 C (106.0 F)
1947
40.6 C (105.1 F)
1948
40.6 C (105.1 F)
1949
42.2 C (108.0 F)
1950
44.4 C (111.9 F)
1951
42.2 C (108.0 F)
1952
40.6 C (105.1 F)
1953
40.6 C (105.1 F)
1954
42.8 C (109.0 F)
1955
42.8 C (109.0 F)
1956
43.3 C (109.9 F)
1957
44.4 C (111.9 F)
1958
41.1 C (106.0 F)
1959
42.8 C (109.0 F)
1960
43.3 C (109.9 F)
1961
44.4 C (111.9 F)
1962
40.6 C (105.1 F)
1963
41.1 C (106.0 F)
1964
43.9 C (111.0 F)
1965
39.4 C (102.9 F)
1966
42.2 C (108.0 F)
1967
42.2 C (108.0 F)
1968
42.2 C (108.0 F)
1969
41.7 C (107.1 F)
1970
42.8 C (109.0 F)
1971
42.8 C (109.0 F)
1972
45.0 C (113.0 F)
1973
43.3 C (109.9 F)
1974
42.8 C (109.0 F)
1975
44.4 C (111.9 F)
1976
44.4 C (111.9 F)
1977
41.7 C (107.1 F)
1978
41.7 C (107.1 F)
1979
43.3 C (109.9 F)
1980
43.3 C (109.9 F)
1981
42.2 C (108.0 F)
1982
41.7 C (107.1 F)
1983
41.7 C (107.1 F)
1984
42.8 C (109.0 F)
1985
42.2 C (108.0 F)
1986
40.6 C (105.1 F)
1987
41.1 C (106.0 F)
1988
42.2 C (108.0 F)
1989
42.2 C (108.0 F)
1990
43.3 C (109.9 F)
1991
43.9 C (111.0 F)
1992
41.1 C (106.0 F)
1993
41.7 C (107.1 F)
1994
42.2 C (108.0 F)
1995
42.2 C (108.0 F)
1996
44.4 C (111.9 F)
1997
43.3 C (109.9 F)
1998
42.8 C (109.0 F)
1999
42.2 C (108.0 F)
2000
42.2 C (108.0 F)
2001
42.8 C (109.0 F)
2002
41.7 C (107.1 F)
2003
41.1 C (106.0 F)
2004
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at Porterville, 1902 to 2004. The record is -8.9 C (16.0 F) in 1990, marked on the chart; the median year is -3.9 C (25.0 F).
Coldest night (TNn) at Porterville by year
Year
Coldest night (TNn)
1902
-2.2 C (28.0 F)
1903
-6.7 C (19.9 F)
1904
-6.7 C (19.9 F)
1905
-6.7 C (19.9 F)
1906
-3.3 C (26.1 F)
1907
-1.7 C (28.9 F)
1908
-5.6 C (21.9 F)
1909
-2.8 C (27.0 F)
1910
-3.3 C (26.1 F)
1911
-4.4 C (24.1 F)
1912
-3.3 C (26.1 F)
1913
-7.8 C (18.0 F)
1914
-1.1 C (30.0 F)
1915
-4.4 C (24.1 F)
1916
-2.8 C (27.0 F)
1917
-5.0 C (23.0 F)
1918
-3.3 C (26.1 F)
1919
-3.9 C (25.0 F)
1920
-3.3 C (26.1 F)
1921
-4.4 C (24.1 F)
1922
-5.6 C (21.9 F)
1923
-5.0 C (23.0 F)
1924
-5.0 C (23.0 F)
1925
-2.8 C (27.0 F)
1926
-5.6 C (21.9 F)
1927
-3.9 C (25.0 F)
1928
-5.0 C (23.0 F)
1929
-6.7 C (19.9 F)
1930
-6.1 C (21.0 F)
1931
-5.6 C (21.9 F)
1932
-4.4 C (24.1 F)
1933
-3.3 C (26.1 F)
1934
-2.2 C (28.0 F)
1935
-4.4 C (24.1 F)
1936
-2.2 C (28.0 F)
1937
-7.2 C (19.0 F)
1938
-3.9 C (25.0 F)
1939
-2.8 C (27.0 F)
1940
-5.0 C (23.0 F)
1941
-1.7 C (28.9 F)
1942
-3.9 C (25.0 F)
1943
-6.1 C (21.0 F)
1944
-2.2 C (28.0 F)
1945
-3.3 C (26.1 F)
1946
-3.9 C (25.0 F)
1947
-3.9 C (25.0 F)
1948
-5.6 C (21.9 F)
1949
-6.7 C (19.9 F)
1950
-7.2 C (19.0 F)
1951
-4.4 C (24.1 F)
1952
-4.4 C (24.1 F)
1953
-3.3 C (26.1 F)
1954
-3.9 C (25.0 F)
1955
-3.9 C (25.0 F)
1956
-3.9 C (25.0 F)
1957
-3.9 C (25.0 F)
1958
-2.8 C (27.0 F)
1959
-3.3 C (26.1 F)
1960
-5.0 C (23.0 F)
1961
-5.0 C (23.0 F)
1962
-6.7 C (19.9 F)
1963
-6.1 C (21.0 F)
1964
-2.8 C (27.0 F)
1965
-3.3 C (26.1 F)
1966
-2.8 C (27.0 F)
1967
-5.6 C (21.9 F)
1968
-4.4 C (24.1 F)
1969
-3.3 C (26.1 F)
1970
-3.9 C (25.0 F)
1971
-5.0 C (23.0 F)
1972
-5.6 C (21.9 F)
1973
-3.9 C (25.0 F)
1974
-4.4 C (24.1 F)
1975
-3.9 C (25.0 F)
1976
-3.9 C (25.0 F)
1977
-3.9 C (25.0 F)
1978
-5.0 C (23.0 F)
1979
-3.3 C (26.1 F)
1980
-2.2 C (28.0 F)
1981
-0.6 C (30.9 F)
1982
-2.8 C (27.0 F)
1983
-0.6 C (30.9 F)
1984
-1.7 C (28.9 F)
1985
-2.8 C (27.0 F)
1986
-0.6 C (30.9 F)
1987
-4.4 C (24.1 F)
1988
-2.8 C (27.0 F)
1989
-5.0 C (23.0 F)
1990
-8.9 C (16.0 F)
1991
-2.8 C (27.0 F)
1992
-3.3 C (26.1 F)
1993
-4.4 C (24.1 F)
1994
-2.2 C (28.0 F)
1995
-0.6 C (30.9 F)
1996
-0.6 C (30.9 F)
1997
-3.3 C (26.1 F)
1998
-6.1 C (21.0 F)
1999
-3.9 C (25.0 F)
2000
-1.7 C (28.9 F)
2001
-1.7 C (28.9 F)
2002
-4.4 C (24.1 F)
2003
-1.7 C (28.9 F)
2004
-1.7 C (28.9 F)
Wettest day (Rx1day)
The wettest day of the year at Porterville, 1902 to 2004. The record is 69.1 mm (2.7 in) in 1969, marked on the chart; the median year is 29.5 mm (1.2 in).
Wettest day (Rx1day) at Porterville by year
Year
Wettest day (Rx1day)
1902
19.1 mm (0.8 in)
1903
14.5 mm (0.6 in)
1904
35.3 mm (1.4 in)
1905
29.2 mm (1.1 in)
1906
38.1 mm (1.5 in)
1907
25.7 mm (1.0 in)
1908
42.9 mm (1.7 in)
1909
33.3 mm (1.3 in)
1910
27.7 mm (1.1 in)
1911
27.7 mm (1.1 in)
1912
24.1 mm (0.9 in)
1913
39.9 mm (1.6 in)
1914
32.5 mm (1.3 in)
1915
27.4 mm (1.1 in)
1916
36.3 mm (1.4 in)
1917
34.5 mm (1.4 in)
1918
33.5 mm (1.3 in)
1919
27.9 mm (1.1 in)
1920
34.8 mm (1.4 in)
1921
32.5 mm (1.3 in)
1922
29.5 mm (1.2 in)
1923
16.8 mm (0.7 in)
1924
33.0 mm (1.3 in)
1925
42.2 mm (1.7 in)
1926
26.4 mm (1.0 in)
1927
35.6 mm (1.4 in)
1928
27.9 mm (1.1 in)
1929
31.8 mm (1.3 in)
1930
31.2 mm (1.2 in)
1931
31.8 mm (1.3 in)
1932
14.7 mm (0.6 in)
1933
49.5 mm (1.9 in)
1934
26.2 mm (1.0 in)
1935
23.6 mm (0.9 in)
1936
43.2 mm (1.7 in)
1937
31.8 mm (1.3 in)
1938
42.7 mm (1.7 in)
1939
25.7 mm (1.0 in)
1940
68.1 mm (2.7 in)
1941
27.9 mm (1.1 in)
1942
27.2 mm (1.1 in)
1943
34.0 mm (1.3 in)
1944
43.9 mm (1.7 in)
1945
41.1 mm (1.6 in)
1946
26.7 mm (1.1 in)
1947
9.9 mm (0.39 in)
1948
29.7 mm (1.2 in)
1949
25.4 mm (1.0 in)
1950
20.3 mm (0.8 in)
1951
31.2 mm (1.2 in)
1952
29.7 mm (1.2 in)
1953
22.6 mm (0.9 in)
1954
43.2 mm (1.7 in)
1955
18.3 mm (0.7 in)
1956
21.3 mm (0.8 in)
1957
23.6 mm (0.9 in)
1958
27.7 mm (1.1 in)
1959
22.6 mm (0.9 in)
1960
31.0 mm (1.2 in)
1961
24.4 mm (1.0 in)
1962
36.6 mm (1.4 in)
1963
26.7 mm (1.1 in)
1964
20.3 mm (0.8 in)
1965
20.3 mm (0.8 in)
1966
59.4 mm (2.3 in)
1967
28.7 mm (1.1 in)
1968
26.9 mm (1.1 in)
1969
69.1 mm (2.7 in)
1970
40.9 mm (1.6 in)
1971
46.5 mm (1.8 in)
1972
54.1 mm (2.1 in)
1973
41.1 mm (1.6 in)
1974
33.0 mm (1.3 in)
1975
18.3 mm (0.7 in)
1976
39.4 mm (1.6 in)
1977
23.1 mm (0.9 in)
1978
46.5 mm (1.8 in)
1979
16.5 mm (0.6 in)
1980
26.7 mm (1.1 in)
1981
40.4 mm (1.6 in)
1982
23.4 mm (0.9 in)
1983
36.1 mm (1.4 in)
1984
20.3 mm (0.8 in)
1985
33.5 mm (1.3 in)
1986
29.5 mm (1.2 in)
1987
17.3 mm (0.7 in)
1988
27.7 mm (1.1 in)
1989
24.6 mm (1.0 in)
1990
17.0 mm (0.7 in)
1991
37.8 mm (1.5 in)
1992
22.9 mm (0.9 in)
1993
27.2 mm (1.1 in)
1994
28.7 mm (1.1 in)
1995
36.8 mm (1.4 in)
1996
32.5 mm (1.3 in)
1997
27.4 mm (1.1 in)
1998
28.4 mm (1.1 in)
1999
38.1 mm (1.5 in)
2000
21.8 mm (0.9 in)
2001
34.3 mm (1.4 in)
2002
29.5 mm (1.2 in)
2003
35.3 mm (1.4 in)
2004
29.2 mm (1.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Porterville, 1902 to 2004. The record is 140.1 mm (5.5 in) in 1966, marked on the chart; the median year is 47.5 mm (1.9 in).
Wettest five days (Rx5day) at Porterville by year
Year
Wettest five days (Rx5day)
1902
26.2 mm (1.0 in)
1903
34.8 mm (1.4 in)
1904
45.0 mm (1.8 in)
1905
71.9 mm (2.8 in)
1906
75.1 mm (3.0 in)
1907
47.5 mm (1.9 in)
1908
52.0 mm (2.0 in)
1909
65.3 mm (2.6 in)
1910
45.0 mm (1.8 in)
1911
39.4 mm (1.6 in)
1912
45.3 mm (1.8 in)
1913
64.6 mm (2.5 in)
1914
71.3 mm (2.8 in)
1915
39.6 mm (1.6 in)
1916
63.0 mm (2.5 in)
1917
58.6 mm (2.3 in)
1918
42.4 mm (1.7 in)
1919
42.9 mm (1.7 in)
1920
36.6 mm (1.4 in)
1921
80.0 mm (3.1 in)
1922
47.0 mm (1.9 in)
1923
30.2 mm (1.2 in)
1924
36.0 mm (1.4 in)
1925
50.6 mm (2.0 in)
1926
79.5 mm (3.1 in)
1927
50.5 mm (2.0 in)
1928
44.7 mm (1.8 in)
1929
32.3 mm (1.3 in)
1930
33.8 mm (1.3 in)
1931
55.1 mm (2.2 in)
1932
43.5 mm (1.7 in)
1933
109.1 mm (4.3 in)
1934
41.7 mm (1.6 in)
1935
49.6 mm (2.0 in)
1936
58.9 mm (2.3 in)
1937
61.0 mm (2.4 in)
1938
95.0 mm (3.7 in)
1939
30.3 mm (1.2 in)
1940
91.2 mm (3.6 in)
1941
42.5 mm (1.7 in)
1942
50.4 mm (2.0 in)
1943
74.4 mm (2.9 in)
1944
63.5 mm (2.5 in)
1945
84.0 mm (3.3 in)
1946
38.2 mm (1.5 in)
1947
14.0 mm (0.6 in)
1948
31.0 mm (1.2 in)
1949
37.1 mm (1.5 in)
1950
28.9 mm (1.1 in)
1951
38.8 mm (1.5 in)
1952
56.6 mm (2.2 in)
1953
29.5 mm (1.2 in)
1954
52.9 mm (2.1 in)
1955
37.9 mm (1.5 in)
1956
47.9 mm (1.9 in)
1957
48.2 mm (1.9 in)
1958
70.9 mm (2.8 in)
1959
34.3 mm (1.4 in)
1960
46.8 mm (1.8 in)
1961
31.5 mm (1.2 in)
1962
105.1 mm (4.1 in)
1963
39.3 mm (1.5 in)
1964
43.2 mm (1.7 in)
1965
51.3 mm (2.0 in)
1966
140.1 mm (5.5 in)
1967
50.5 mm (2.0 in)
1968
31.2 mm (1.2 in)
1969
101.3 mm (4.0 in)
1970
75.5 mm (3.0 in)
1971
67.0 mm (2.6 in)
1972
60.5 mm (2.4 in)
1973
71.1 mm (2.8 in)
1974
46.0 mm (1.8 in)
1975
42.6 mm (1.7 in)
1976
62.6 mm (2.5 in)
1977
46.8 mm (1.8 in)
1978
104.6 mm (4.1 in)
1979
31.5 mm (1.2 in)
1980
65.5 mm (2.6 in)
1981
43.0 mm (1.7 in)
1982
52.1 mm (2.1 in)
1983
78.8 mm (3.1 in)
1984
35.8 mm (1.4 in)
1985
53.1 mm (2.1 in)
1986
63.2 mm (2.5 in)
1987
36.4 mm (1.4 in)
1988
39.7 mm (1.6 in)
1989
30.2 mm (1.2 in)
1990
37.8 mm (1.5 in)
1991
70.5 mm (2.8 in)
1992
59.0 mm (2.3 in)
1993
62.8 mm (2.5 in)
1994
35.1 mm (1.4 in)
1995
57.7 mm (2.3 in)
1996
47.2 mm (1.9 in)
1997
45.5 mm (1.8 in)
1998
87.6 mm (3.4 in)
1999
81.3 mm (3.2 in)
2000
45.9 mm (1.8 in)
2001
37.4 mm (1.5 in)
2002
54.4 mm (2.1 in)
2003
45.9 mm (1.8 in)
2004
39.2 mm (1.5 in)
Longest dry spell (CDD)
The longest dry spell of the year at Porterville, 1902 to 2004. The record is 216 days in 1914, marked on the chart; the median year is 122 days.
Longest dry spell (CDD) at Porterville by year
Year
Longest dry spell (CDD)
1902
61 days
1903
166 days
1904
145 days
1905
122 days
1906
160 days
1907
115 days
1908
116 days
1909
105 days
1910
111 days
1911
154 days
1912
61 days
1913
62 days
1914
216 days
1915
22 days
1916
29 days
1917
49 days
1918
31 days
1919
36 days
1920
22 days
1921
30 days
1922
35 days
1923
22 days
1924
38 days
1925
50 days
1926
153 days
1927
175 days
1928
178 days
1929
94 days
1930
121 days
1931
86 days
1932
207 days
1933
146 days
1934
133 days
1935
165 days
1936
68 days
1937
169 days
1938
116 days
1939
101 days
1940
180 days
1941
171 days
1942
175 days
1943
166 days
1944
155 days
1945
124 days
1946
85 days
1947
73 days
1948
102 days
1949
175 days
1950
91 days
1951
177 days
1952
200 days
1953
140 days
1954
154 days
1955
189 days
1956
143 days
1957
122 days
1958
66 days
1959
93 days
1960
76 days
1961
105 days
1962
134 days
1963
55 days
1964
96 days
1965
108 days
1966
152 days
1967
105 days
1968
126 days
1969
62 days
1970
193 days
1971
167 days
1972
90 days
1973
160 days
1974
159 days
1975
164 days
1976
65 days
1977
78 days
1978
131 days
1979
184 days
1980
120 days
1981
143 days
1982
79 days
1983
85 days
1984
94 days
1985
123 days
1986
161 days
1987
123 days
1988
146 days
1989
164 days
1990
116 days
1991
187 days
1992
204 days
1993
126 days
1994
61 days
1995
178 days
1996
162 days
1997
186 days
1998
84 days
1999
144 days
2000
83 days
2001
116 days
2002
169 days
2003
175 days
2004
73 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
88 years with a frost
Across 88 years with a frost, the median last spring frost at Porterville falls on 25 February and the median first autumn frost on 28 November, which leaves a median of 280 days between them.
In 1971 to 2002 the median growing season was 295 days. That is 47 days more than in 1908 to 1940.
Fitted over all years, the growing season changes by +5.4 days per decade at this station.
Frost dates and growing season at Porterville
Measure
Median, all years
Earliest period (1908 to 1940)
Recent period (1971 to 2002)
Recent against earliest
Fitted trend
Last spring frost
25 February
21 March
7 February
42 days earlier
-4.1 days per decade
First autumn frost
28 November
25 November
28 November
3 days later
+1.3 days per decade
Growing days
280 days
248 days
295 days
47 days more
+5.4 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
87 years, 1904 to 2003
A day with at least 29.5 mm (1.2 in) of rain is expected about once in 2 years. A day with at least 65.2 mm (2.6 in) of rain is expected about once in 100 years.
Rainfall return levels at Porterville: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
29.5 mm (1.2 in)
5 years
38.8 mm (1.5 in)
10 years
45.0 mm (1.8 in)
25 years
53.1 mm (2.1 in)
50 years
59.1 mm (2.3 in)
100 years
65.2 mm (2.6 in)
Longer than the 87 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, 87 years of values from 1904 to 2003.
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: 69.1 mm (2.7 in) in 1969; 68.1 mm (2.7 in) in 1940; 59.4 mm (2.3 in) in 1966.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Porterville standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Porterville 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.