Record envelope, standing records and threshold days for Holtwood (USC00364019), Pennsylvania, United States, with 86 years of record.
Key Facts for Holtwood
Holtwood (USC00364019) is a weather station in Pennsylvania, United States at 39.83 latitude and -76.33 longitude, 58 m (190 ft) above sea level.
The station reports from 1914 to 1999, 86 years of record.
1,464 records set at Holtwood still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Holtwood set a daily record high maximum temperature of 19.4 C (66.9 F) on 12 February 1999.
About the Station
Location: Pennsylvania, United States, 39.83 latitude, -76.33 longitude.
Elevation: 58 m (190 ft).
Period of record: 1914 to 1999, 86 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 Holtwood. 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 Holtwood, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
24.4 C (75.9 F)
-22.2 C (-8.0 F)
n/a
n/a
Feb
25.6 C (78.1 F)
-22.8 C (-9.0 F)
n/a
n/a
Mar
30.0 C (86.0 F)
-13.9 C (7.0 F)
n/a
n/a
Apr
32.8 C (91.0 F)
-11.1 C (12.0 F)
n/a
n/a
May
36.7 C (98.1 F)
0.0 C (32.0 F)
n/a
n/a
Jun
37.8 C (100.0 F)
6.1 C (43.0 F)
n/a
n/a
Jul
40.0 C (104.0 F)
10.6 C (51.1 F)
n/a
n/a
Aug
40.0 C (104.0 F)
7.2 C (45.0 F)
n/a
n/a
Sep
40.0 C (104.0 F)
3.3 C (37.9 F)
n/a
n/a
Oct
35.0 C (95.0 F)
-3.3 C (26.1 F)
n/a
n/a
Nov
28.3 C (82.9 F)
-11.1 C (12.0 F)
n/a
n/a
Dec
23.3 C (73.9 F)
-17.8 C (0.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Holtwood still stand. 1931 holds the most, with 59.
Standing records at Holtwood by the year they were set
Year set
Standing records
1919
7
1920
19
1921
28
1922
19
1923
31
1924
18
1925
27
1926
31
1927
31
1928
21
1929
41
1930
56
1931
59
1932
32
1933
22
1934
34
1935
19
1936
33
1937
15
1938
17
1939
6
1940
30
1941
18
1942
18
1943
10
1944
14
1945
18
1946
20
1947
18
1948
4
1949
14
1950
14
1951
16
1952
10
1953
15
1954
13
1955
12
1956
22
1957
15
1958
7
1959
11
1960
13
1961
13
1962
15
1963
15
1964
16
1965
12
1966
15
1967
14
1968
11
1969
4
1970
8
1971
9
1972
14
1973
5
1974
20
1975
17
1976
31
1977
16
1978
12
1979
25
1980
13
1981
6
1982
19
1983
22
1984
21
1985
13
1986
12
1987
16
1988
28
1989
19
1990
30
1991
22
1992
12
1993
9
1994
8
1995
7
1996
24
1997
23
1998
9
1999
1
All-Time Record Progression
4 new records
4 all-time records were set at Holtwood between 16 February 1958 and 21 January 1985. Each dot is a new record.
When Holtwood set new all-time records
Date
Kind
Detail
1958-02-16
Record daily snowfall
Record daily snowfall 55.9 cm (22.0 in)
1958-03-20
Record daily snowfall
Record daily snowfall 63.5 cm (25.0 in)
1970-01-09
Record low maximum temperature
Record low maximum temperature -12.8 C (9.0 F)
1985-01-21
Record low maximum temperature
Record low maximum temperature -14.4 C (6.1 F)
Wettest Day of Each Month
Aug: 139.7 mm (5.5 in)
The wettest day on record for each calendar month at Holtwood. The most was 139.7 mm (5.5 in) on 23 August 1933.
Record daily precipitation for each month at Holtwood
Month
Record daily precipitation (mm)
Date
Jan
55.6 mm (2.2 in)
26 January 1978
Feb
89.9 mm (3.5 in)
2 February 1915
Mar
83.8 mm (3.3 in)
20 March 1958
Apr
71.1 mm (2.8 in)
16 April 1983
May
94.0 mm (3.7 in)
5 May 1989
Jun
102.9 mm (4.1 in)
22 June 1972
Jul
116.8 mm (4.6 in)
26 July 1916
Aug
139.7 mm (5.5 in)
23 August 1933
Sep
112.0 mm (4.4 in)
22 September 1979
Oct
78.2 mm (3.1 in)
24 October 1923
Nov
93.7 mm (3.7 in)
28 November 1993
Dec
82.3 mm (3.2 in)
25 December 1986
Period of Record Coverage
1919 to 1999
Complete yearUnder 90 percent of days
81 years of record at Holtwood, 1919 to 1999. 6 years have data for under 90 percent of days and are left out of rankings: 1919, 1924, 1948, 1973, 1998, 1999.
Cooler than the station meanWarmer than the station mean
One stripe for each of 69 complete years at Holtwood, 1920 to 1997. Blue stripes are years cooler than the station's own mean of 12.1 C (53.7 F); red stripes are warmer. The coolest year was 1988, at 10.4 C (50.7 F), and the warmest was 1931, at 14.3 C (57.8 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Holtwood as warming stripes, 1920 to 1997
Year
Annual mean temperature
Difference from the station mean
1920
12.0 C
-0.06 C
1921
13.4 C
+1.33 C
1922
12.5 C
+0.42 C
1923
11.7 C
-0.42 C
1926
10.7 C
-1.36 C
1927
11.9 C
-0.23 C
1928
11.9 C
-0.17 C
1929
12.8 C
+0.76 C
1930
13.4 C
+1.31 C
1931
14.3 C
+2.25 C
1934
12.0 C
-0.05 C
1935
12.1 C
+0.04 C
1936
12.3 C
+0.25 C
1937
12.3 C
+0.21 C
1938
12.9 C
+0.81 C
1939
12.8 C
+0.69 C
1940
11.1 C
-0.99 C
1941
13.0 C
+0.88 C
1942
12.5 C
+0.38 C
1943
12.2 C
+0.15 C
1944
12.5 C
+0.45 C
1945
12.5 C
+0.42 C
1946
13.0 C
+0.87 C
1947
12.0 C
-0.10 C
1949
13.5 C
+1.41 C
1950
12.0 C
-0.05 C
1951
12.5 C
+0.37 C
1952
12.8 C
+0.69 C
1953
13.3 C
+1.20 C
1954
12.7 C
+0.66 C
1955
12.5 C
+0.42 C
1956
12.0 C
-0.09 C
1957
12.6 C
+0.54 C
1958
11.0 C
-1.04 C
1960
11.6 C
-0.44 C
1961
11.9 C
-0.18 C
1962
11.4 C
-0.69 C
1963
11.3 C
-0.75 C
1964
12.1 C
-0.01 C
1965
11.9 C
-0.21 C
1966
11.6 C
-0.44 C
1968
11.7 C
-0.42 C
1969
11.9 C
-0.19 C
1970
11.8 C
-0.28 C
1971
11.8 C
-0.27 C
1974
12.2 C
+0.12 C
1975
12.5 C
+0.45 C
1976
11.6 C
-0.45 C
1977
12.1 C
+0.01 C
1978
11.4 C
-0.65 C
1979
11.7 C
-0.35 C
1980
12.2 C
+0.09 C
1981
11.7 C
-0.35 C
1982
11.7 C
-0.38 C
1983
11.4 C
-0.71 C
1984
11.4 C
-0.70 C
1985
12.2 C
+0.08 C
1986
11.9 C
-0.18 C
1987
11.3 C
-0.75 C
1988
10.4 C
-1.69 C
1989
10.9 C
-1.14 C
1990
13.4 C
+1.28 C
1991
13.4 C
+1.36 C
1992
11.4 C
-0.73 C
1993
12.0 C
-0.04 C
1994
11.6 C
-0.49 C
1995
11.6 C
-0.48 C
1996
10.6 C
-1.52 C
1997
11.1 C
-0.95 C
The annual mean temperature here has fallen by 0.1 C (0.1 to 0.2) per decade over 1920 to 1997. In Fahrenheit: 0.2 F (0.1 to 0.4) per decade. The slope is a straight line fitted to 69 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Holtwood
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.2 to -0.1) per decade
-0.2 F (-0.4 to -0.1) per decade
1920 to 1997
69
Fall
Mean daily maximum
-0.09 C (-0.18 to 0.00) per decade
-0.16 F (-0.32 to 0.00) per decade
1920 to 1997
69
Fall
Mean daily minimum
-0.2 C (-0.3 to -0.1) per decade
-0.3 F (-0.5 to -0.2) per decade
1920 to 1997
69
Fall
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
1914 to 1999
Yearly extremes at Holtwood: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
1930
35.0 C (95.0 F)
81
Coldest night (TNn)
-22.8 C (-9.0 F)
1934
-15.0 C (5.0 F)
81
Wettest day (Rx1day)
139.7 mm (5.5 in)
1933
61.2 mm (2.4 in)
86
Wettest five days (Rx5day)
207.1 mm (8.2 in)
1933
88.1 mm (3.5 in)
86
Longest dry spell (CDD)
45 days
1924
18 days
86
Hottest day (TXx)
The hottest day of the year at Holtwood, 1914 to 1999. The record is 40.0 C (104.0 F) in 1930, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Holtwood by year
Year
Hottest day (TXx)
1914
n/a
1915
n/a
1916
n/a
1917
n/a
1918
n/a
1919
33.3 C (91.9 F)
1920
37.2 C (99.0 F)
1921
37.2 C (99.0 F)
1922
36.1 C (97.0 F)
1923
35.0 C (95.0 F)
1924
36.1 C (97.0 F)
1925
36.1 C (97.0 F)
1926
37.2 C (99.0 F)
1927
33.9 C (93.0 F)
1928
35.0 C (95.0 F)
1929
37.8 C (100.0 F)
1930
40.0 C (104.0 F)
1931
40.0 C (104.0 F)
1932
37.8 C (100.0 F)
1933
36.1 C (97.0 F)
1934
36.7 C (98.1 F)
1935
34.4 C (93.9 F)
1936
38.3 C (100.9 F)
1937
33.9 C (93.0 F)
1938
35.0 C (95.0 F)
1939
36.1 C (97.0 F)
1940
37.8 C (100.0 F)
1941
36.7 C (98.1 F)
1942
35.0 C (95.0 F)
1943
36.1 C (97.0 F)
1944
36.7 C (98.1 F)
1945
35.0 C (95.0 F)
1946
33.9 C (93.0 F)
1947
35.0 C (95.0 F)
1948
37.2 C (99.0 F)
1949
35.6 C (96.1 F)
1950
33.3 C (91.9 F)
1951
33.9 C (93.0 F)
1952
36.7 C (98.1 F)
1953
37.2 C (99.0 F)
1954
37.2 C (99.0 F)
1955
37.2 C (99.0 F)
1956
36.1 C (97.0 F)
1957
36.7 C (98.1 F)
1958
33.3 C (91.9 F)
1959
34.4 C (93.9 F)
1960
32.2 C (90.0 F)
1961
33.9 C (93.0 F)
1962
35.0 C (95.0 F)
1963
35.0 C (95.0 F)
1964
35.0 C (95.0 F)
1965
34.4 C (93.9 F)
1966
38.3 C (100.9 F)
1967
35.0 C (95.0 F)
1968
34.4 C (93.9 F)
1969
35.0 C (95.0 F)
1970
33.3 C (91.9 F)
1971
34.4 C (93.9 F)
1972
33.3 C (91.9 F)
1973
33.9 C (93.0 F)
1974
33.9 C (93.0 F)
1975
35.6 C (96.1 F)
1976
33.3 C (91.9 F)
1977
36.1 C (97.0 F)
1978
35.6 C (96.1 F)
1979
33.3 C (91.9 F)
1980
37.2 C (99.0 F)
1981
33.9 C (93.0 F)
1982
33.9 C (93.0 F)
1983
37.2 C (99.0 F)
1984
35.0 C (95.0 F)
1985
35.6 C (96.1 F)
1986
33.3 C (91.9 F)
1987
34.4 C (93.9 F)
1988
35.6 C (96.1 F)
1989
33.9 C (93.0 F)
1990
35.6 C (96.1 F)
1991
37.8 C (100.0 F)
1992
35.0 C (95.0 F)
1993
35.6 C (96.1 F)
1994
35.0 C (95.0 F)
1995
36.1 C (97.0 F)
1996
36.7 C (98.1 F)
1997
37.2 C (99.0 F)
1998
34.4 C (93.9 F)
1999
21.7 C (71.1 F)
Coldest night (TNn)
The coldest night of the year at Holtwood, 1914 to 1999. The record is -22.8 C (-9.0 F) in 1934, marked on the chart; the median year is -15.0 C (5.0 F).
Coldest night (TNn) at Holtwood by year
Year
Coldest night (TNn)
1914
n/a
1915
n/a
1916
n/a
1917
n/a
1918
n/a
1919
-17.8 C (0.0 F)
1920
-16.7 C (1.9 F)
1921
-15.0 C (5.0 F)
1922
-17.8 C (0.0 F)
1923
-13.9 C (7.0 F)
1924
-15.0 C (5.0 F)
1925
-12.2 C (10.0 F)
1926
-15.6 C (3.9 F)
1927
-16.1 C (3.0 F)
1928
-16.7 C (1.9 F)
1929
-12.8 C (9.0 F)
1930
-16.7 C (1.9 F)
1931
-11.1 C (12.0 F)
1932
-13.3 C (8.1 F)
1933
-13.9 C (7.0 F)
1934
-22.8 C (-9.0 F)
1935
-19.4 C (-2.9 F)
1936
-20.0 C (-4.0 F)
1937
-9.4 C (15.1 F)
1938
-12.2 C (10.0 F)
1939
-12.8 C (9.0 F)
1940
-16.1 C (3.0 F)
1941
-9.4 C (15.1 F)
1942
-17.2 C (1.0 F)
1943
-15.0 C (5.0 F)
1944
-12.8 C (9.0 F)
1945
-15.0 C (5.0 F)
1946
-12.2 C (10.0 F)
1947
-14.4 C (6.1 F)
1948
-12.2 C (10.0 F)
1949
-9.4 C (15.1 F)
1950
-12.8 C (9.0 F)
1951
-13.9 C (7.0 F)
1952
-11.1 C (12.0 F)
1953
-7.8 C (18.0 F)
1954
-12.8 C (9.0 F)
1955
-16.1 C (3.0 F)
1956
-10.0 C (14.0 F)
1957
-16.1 C (3.0 F)
1958
-15.0 C (5.0 F)
1959
-15.0 C (5.0 F)
1960
-15.0 C (5.0 F)
1961
-18.9 C (-2.0 F)
1962
-15.6 C (3.9 F)
1963
-19.4 C (-2.9 F)
1964
-15.0 C (5.0 F)
1965
-16.1 C (3.0 F)
1966
-16.7 C (1.9 F)
1967
-15.6 C (3.9 F)
1968
-15.6 C (3.9 F)
1969
-12.2 C (10.0 F)
1970
-18.3 C (-0.9 F)
1971
-15.6 C (3.9 F)
1972
-16.1 C (3.0 F)
1973
-5.6 C (21.9 F)
1974
-10.0 C (14.0 F)
1975
-11.7 C (10.9 F)
1976
-13.9 C (7.0 F)
1977
-21.7 C (-7.1 F)
1978
-17.2 C (1.0 F)
1979
-22.8 C (-9.0 F)
1980
-15.0 C (5.0 F)
1981
-16.7 C (1.9 F)
1982
-21.1 C (-6.0 F)
1983
-17.8 C (0.0 F)
1984
-21.1 C (-6.0 F)
1985
-22.2 C (-8.0 F)
1986
-13.3 C (8.1 F)
1987
-16.1 C (3.0 F)
1988
-18.3 C (-0.9 F)
1989
-15.0 C (5.0 F)
1990
-11.7 C (10.9 F)
1991
-10.6 C (12.9 F)
1992
-11.7 C (10.9 F)
1993
-13.9 C (7.0 F)
1994
-22.2 C (-8.0 F)
1995
-15.0 C (5.0 F)
1996
-17.2 C (1.0 F)
1997
-16.1 C (3.0 F)
1998
-11.7 C (10.9 F)
1999
-10.6 C (12.9 F)
Wettest day (Rx1day)
The wettest day of the year at Holtwood, 1914 to 1999. The record is 139.7 mm (5.5 in) in 1933, marked on the chart; the median year is 61.2 mm (2.4 in).
Wettest day (Rx1day) at Holtwood by year
Year
Wettest day (Rx1day)
1914
49.3 mm (1.9 in)
1915
89.9 mm (3.5 in)
1916
116.8 mm (4.6 in)
1917
63.8 mm (2.5 in)
1918
43.9 mm (1.7 in)
1919
103.6 mm (4.1 in)
1920
50.8 mm (2.0 in)
1921
45.7 mm (1.8 in)
1922
68.1 mm (2.7 in)
1923
78.2 mm (3.1 in)
1924
52.1 mm (2.1 in)
1925
39.6 mm (1.6 in)
1926
45.7 mm (1.8 in)
1927
86.4 mm (3.4 in)
1928
88.9 mm (3.5 in)
1929
60.7 mm (2.4 in)
1930
40.6 mm (1.6 in)
1931
46.7 mm (1.8 in)
1932
60.5 mm (2.4 in)
1933
139.7 mm (5.5 in)
1934
42.4 mm (1.7 in)
1935
77.2 mm (3.0 in)
1936
54.6 mm (2.1 in)
1937
67.3 mm (2.6 in)
1938
91.4 mm (3.6 in)
1939
64.0 mm (2.5 in)
1940
50.8 mm (2.0 in)
1941
38.6 mm (1.5 in)
1942
78.7 mm (3.1 in)
1943
48.3 mm (1.9 in)
1944
38.1 mm (1.5 in)
1945
43.9 mm (1.7 in)
1946
77.0 mm (3.0 in)
1947
43.2 mm (1.7 in)
1948
54.6 mm (2.1 in)
1949
59.9 mm (2.4 in)
1950
51.6 mm (2.0 in)
1951
62.5 mm (2.5 in)
1952
61.7 mm (2.4 in)
1953
65.5 mm (2.6 in)
1954
35.6 mm (1.4 in)
1955
108.0 mm (4.3 in)
1956
59.2 mm (2.3 in)
1957
44.5 mm (1.8 in)
1958
83.8 mm (3.3 in)
1959
86.4 mm (3.4 in)
1960
71.1 mm (2.8 in)
1961
31.5 mm (1.2 in)
1962
66.8 mm (2.6 in)
1963
63.2 mm (2.5 in)
1964
96.8 mm (3.8 in)
1965
47.0 mm (1.9 in)
1966
70.4 mm (2.8 in)
1967
52.1 mm (2.1 in)
1968
79.2 mm (3.1 in)
1969
54.1 mm (2.1 in)
1970
66.8 mm (2.6 in)
1971
64.3 mm (2.5 in)
1972
102.9 mm (4.1 in)
1973
27.9 mm (1.1 in)
1974
38.4 mm (1.5 in)
1975
71.4 mm (2.8 in)
1976
49.0 mm (1.9 in)
1977
55.4 mm (2.2 in)
1978
78.2 mm (3.1 in)
1979
112.0 mm (4.4 in)
1980
40.4 mm (1.6 in)
1981
49.8 mm (2.0 in)
1982
42.9 mm (1.7 in)
1983
71.1 mm (2.8 in)
1984
59.7 mm (2.4 in)
1985
77.0 mm (3.0 in)
1986
82.3 mm (3.2 in)
1987
105.9 mm (4.2 in)
1988
68.8 mm (2.7 in)
1989
94.0 mm (3.7 in)
1990
41.9 mm (1.6 in)
1991
63.5 mm (2.5 in)
1992
58.4 mm (2.3 in)
1993
93.7 mm (3.7 in)
1994
83.8 mm (3.3 in)
1995
53.8 mm (2.1 in)
1996
61.7 mm (2.4 in)
1997
34.8 mm (1.4 in)
1998
47.5 mm (1.9 in)
1999
27.9 mm (1.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Holtwood, 1914 to 1999. The record is 207.1 mm (8.2 in) in 1933, marked on the chart; the median year is 88.1 mm (3.5 in).
Wettest five days (Rx5day) at Holtwood by year
Year
Wettest five days (Rx5day)
1914
75.0 mm (3.0 in)
1915
152.6 mm (6.0 in)
1916
178.8 mm (7.0 in)
1917
83.8 mm (3.3 in)
1918
65.9 mm (2.6 in)
1919
188.4 mm (7.4 in)
1920
128.7 mm (5.1 in)
1921
78.2 mm (3.1 in)
1922
71.7 mm (2.8 in)
1923
84.3 mm (3.3 in)
1924
81.8 mm (3.2 in)
1925
45.4 mm (1.8 in)
1926
77.4 mm (3.0 in)
1927
96.6 mm (3.8 in)
1928
124.4 mm (4.9 in)
1929
118.4 mm (4.7 in)
1930
44.2 mm (1.7 in)
1931
63.7 mm (2.5 in)
1932
77.5 mm (3.1 in)
1933
207.1 mm (8.2 in)
1934
84.8 mm (3.3 in)
1935
94.0 mm (3.7 in)
1936
64.7 mm (2.5 in)
1937
117.8 mm (4.6 in)
1938
140.4 mm (5.5 in)
1939
110.8 mm (4.4 in)
1940
94.3 mm (3.7 in)
1941
72.2 mm (2.8 in)
1942
101.1 mm (4.0 in)
1943
110.9 mm (4.4 in)
1944
69.9 mm (2.8 in)
1945
113.5 mm (4.5 in)
1946
89.3 mm (3.5 in)
1947
71.4 mm (2.8 in)
1948
65.3 mm (2.6 in)
1949
69.8 mm (2.7 in)
1950
84.0 mm (3.3 in)
1951
73.5 mm (2.9 in)
1952
111.2 mm (4.4 in)
1953
97.0 mm (3.8 in)
1954
37.9 mm (1.5 in)
1955
197.9 mm (7.8 in)
1956
86.9 mm (3.4 in)
1957
77.0 mm (3.0 in)
1958
112.5 mm (4.4 in)
1959
129.4 mm (5.1 in)
1960
182.6 mm (7.2 in)
1961
68.0 mm (2.7 in)
1962
103.9 mm (4.1 in)
1963
83.0 mm (3.3 in)
1964
96.8 mm (3.8 in)
1965
76.5 mm (3.0 in)
1966
90.2 mm (3.6 in)
1967
93.5 mm (3.7 in)
1968
91.7 mm (3.6 in)
1969
77.0 mm (3.0 in)
1970
87.8 mm (3.5 in)
1971
136.7 mm (5.4 in)
1972
179.6 mm (7.1 in)
1973
56.4 mm (2.2 in)
1974
57.6 mm (2.3 in)
1975
174.2 mm (6.9 in)
1976
82.0 mm (3.2 in)
1977
97.3 mm (3.8 in)
1978
97.0 mm (3.8 in)
1979
113.5 mm (4.5 in)
1980
65.2 mm (2.6 in)
1981
100.1 mm (3.9 in)
1982
73.1 mm (2.9 in)
1983
78.5 mm (3.1 in)
1984
74.9 mm (2.9 in)
1985
108.5 mm (4.3 in)
1986
82.3 mm (3.2 in)
1987
120.4 mm (4.7 in)
1988
119.8 mm (4.7 in)
1989
125.8 mm (5.0 in)
1990
110.3 mm (4.3 in)
1991
69.1 mm (2.7 in)
1992
60.2 mm (2.4 in)
1993
102.4 mm (4.0 in)
1994
116.8 mm (4.6 in)
1995
68.3 mm (2.7 in)
1996
84.1 mm (3.3 in)
1997
53.6 mm (2.1 in)
1998
88.4 mm (3.5 in)
1999
38.7 mm (1.5 in)
Longest dry spell (CDD)
The longest dry spell of the year at Holtwood, 1914 to 1999. The record is 45 days in 1924, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Holtwood by year
Year
Longest dry spell (CDD)
1914
20 days
1915
15 days
1916
23 days
1917
20 days
1918
20 days
1919
12 days
1920
26 days
1921
13 days
1922
25 days
1923
20 days
1924
45 days
1925
16 days
1926
15 days
1927
16 days
1928
12 days
1929
17 days
1930
26 days
1931
18 days
1932
20 days
1933
14 days
1934
15 days
1935
15 days
1936
20 days
1937
19 days
1938
15 days
1939
25 days
1940
18 days
1941
28 days
1942
13 days
1943
27 days
1944
19 days
1945
16 days
1946
17 days
1947
33 days
1948
18 days
1949
21 days
1950
15 days
1951
21 days
1952
16 days
1953
18 days
1954
23 days
1955
21 days
1956
13 days
1957
17 days
1958
25 days
1959
17 days
1960
18 days
1961
16 days
1962
15 days
1963
31 days
1964
27 days
1965
26 days
1966
21 days
1967
16 days
1968
26 days
1969
17 days
1970
15 days
1971
22 days
1972
21 days
1973
18 days
1974
16 days
1975
15 days
1976
28 days
1977
20 days
1978
19 days
1979
15 days
1980
24 days
1981
25 days
1982
16 days
1983
18 days
1984
17 days
1985
16 days
1986
22 days
1987
22 days
1988
24 days
1989
20 days
1990
15 days
1991
23 days
1992
18 days
1993
18 days
1994
18 days
1995
27 days
1996
11 days
1997
20 days
1998
16 days
1999
9 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
69 years with a frost
Across 69 years with a frost, the median last spring frost at Holtwood falls on 9 April and the median first autumn frost on 6 November, which leaves a median of 211 days between them.
In 1965 to 1997 the median growing season was 208 days. That is 12 days fewer than in 1920 to 1954.
Fitted over all years, the growing season changes by -0.5 days per decade at this station.
Frost dates and growing season at Holtwood
Measure
Median, all years
Earliest period (1920 to 1954)
Recent period (1965 to 1997)
Recent against earliest
Fitted trend
Last spring frost
9 April
5 April
10 April
5 days later
+0.5 days per decade
First autumn frost
6 November
6 November
4 November
2 days earlier
0.0 days per decade
Growing days
211 days
220 days
208 days
12 days fewer
-0.5 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
80 years, 1915 to 1997
A day with at least 62.2 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 136.2 mm (5.4 in) of rain is expected about once in 100 years.
Rainfall return levels at Holtwood: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
62.2 mm (2.4 in)
5 years
82.2 mm (3.2 in)
10 years
95.4 mm (3.8 in)
25 years
111.9 mm (4.4 in)
50 years
124.1 mm (4.9 in)
100 years
136.2 mm (5.4 in)
Longer than the 80 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, 80 years of values from 1915 to 1997.
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: 139.7 mm (5.5 in) in 1933; 116.8 mm (4.6 in) in 1916; 112.0 mm (4.4 in) in 1979.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Holtwood, at 1929 and 1961. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1929 ran 0.4 C (0.8 F) higher than in the years before (likely change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1961 ran 0.3 C (0.5 F) lower than in the years before (possible change).
Suspected changes in the annual mean temperature at Holtwood, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1929
+0.4
+0.8
likely
5
1961
-0.3
-0.5
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 Holtwood standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Holtwood 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.