Record envelope, standing records and threshold days for Port Clinton (USC00367116), Pennsylvania, United States, with 42 years of record.
Key Facts for Port Clinton
Port Clinton (USC00367116) is a weather station in Pennsylvania, United States at 40.58 latitude and -76.03 longitude, 137 m (449 ft) above sea level.
The station reports from 1938 to 1979, 42 years of record.
1,464 records set at Port Clinton still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Port Clinton set a daily record precipitation of 27.2 mm (1.1 in) on 24 May 1979.
About the Station
Location: Pennsylvania, United States, 40.58 latitude, -76.03 longitude.
Elevation: 137 m (449 ft).
Period of record: 1938 to 1979, 42 years.
Eligible elements: tmax, tmin, prcp, snow.
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 Port Clinton. 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 Port Clinton, 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)
-30.0 C (-22.0 F)
n/a
n/a
Feb
21.1 C (70.0 F)
-24.4 C (-11.9 F)
n/a
n/a
Mar
28.9 C (84.0 F)
-21.7 C (-7.1 F)
n/a
n/a
Apr
33.9 C (93.0 F)
-11.7 C (10.9 F)
n/a
n/a
May
35.0 C (95.0 F)
-6.1 C (21.0 F)
n/a
n/a
Jun
37.8 C (100.0 F)
0.0 C (32.0 F)
n/a
n/a
Jul
40.0 C (104.0 F)
2.8 C (37.0 F)
n/a
n/a
Aug
37.8 C (100.0 F)
1.7 C (35.1 F)
n/a
n/a
Sep
38.3 C (100.9 F)
-5.0 C (23.0 F)
n/a
n/a
Oct
33.3 C (91.9 F)
-11.7 C (10.9 F)
n/a
n/a
Nov
27.8 C (82.0 F)
-16.7 C (1.9 F)
n/a
n/a
Dec
19.4 C (66.9 F)
-24.4 C (-11.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Port Clinton still stand. 1964 holds the most, with 70.
Standing records at Port Clinton by the year they were set
Year set
Standing records
1938
14
1939
52
1940
45
1941
35
1942
50
1943
44
1944
22
1945
43
1946
33
1947
35
1948
27
1949
36
1950
43
1951
37
1952
26
1953
32
1954
31
1955
33
1956
24
1957
34
1958
19
1959
35
1960
39
1961
35
1962
39
1963
48
1964
70
1965
48
1966
40
1967
37
1968
36
1969
22
1970
34
1971
16
1972
28
1973
30
1974
25
1975
41
1976
60
1977
27
1978
16
1979
23
All-Time Record Progression
1 new records
1 all-time records were set at Port Clinton between 7 February 1978 and 7 February 1978. Each dot is a new record.
When Port Clinton set new all-time records
Date
Kind
Detail
1978-02-07
Record daily snowfall
Record daily snowfall 48.3 cm (19.0 in)
Wettest Day of Each Month
Sep: 120.1 mm (4.7 in)
The wettest day on record for each calendar month at Port Clinton. The most was 120.1 mm (4.7 in) on 27 September 1942.
Record daily precipitation for each month at Port Clinton
Month
Record daily precipitation (mm)
Date
Jan
116.8 mm (4.6 in)
26 January 1976
Feb
69.9 mm (2.8 in)
8 February 1965
Mar
67.6 mm (2.7 in)
27 March 1978
Apr
53.3 mm (2.1 in)
1 April 1976
May
96.5 mm (3.8 in)
22 May 1942
Jun
96.5 mm (3.8 in)
19 June 1967
Jul
111.8 mm (4.4 in)
9 July 1952
Aug
81.0 mm (3.2 in)
19 August 1955
Sep
120.1 mm (4.7 in)
27 September 1942
Oct
73.7 mm (2.9 in)
22 October 1970
Nov
86.4 mm (3.4 in)
9 November 1943
Dec
81.3 mm (3.2 in)
7 December 1953
Period of Record Coverage
1938 to 1979
Complete yearUnder 90 percent of days
42 years of record at Port Clinton, 1938 to 1979. 3 years have data for under 90 percent of days and are left out of rankings: 1938, 1955, 1979.
Cooler than the station meanWarmer than the station mean
One stripe for each of 37 complete years at Port Clinton, 1939 to 1978. Blue stripes are years cooler than the station's own mean of 9.5 C (49.2 F); red stripes are warmer. The coolest year was 1963, at 8.0 C (46.4 F), and the warmest was 1939, at 11.2 C (52.2 F). The strongest colour marks a difference of 1.7 C (3.1 F).
Annual mean temperature at Port Clinton as warming stripes, 1939 to 1978
Year
Annual mean temperature
Difference from the station mean
1939
11.2 C
+1.67 C
1940
9.4 C
-0.19 C
1941
11.0 C
+1.44 C
1942
10.8 C
+1.20 C
1943
10.1 C
+0.50 C
1944
10.0 C
+0.44 C
1945
10.0 C
+0.42 C
1946
10.7 C
+1.18 C
1947
9.8 C
+0.24 C
1949
10.8 C
+1.21 C
1950
9.1 C
-0.47 C
1951
9.6 C
+0.06 C
1952
10.0 C
+0.40 C
1953
10.5 C
+0.91 C
1954
9.7 C
+0.13 C
1957
10.4 C
+0.80 C
1958
9.1 C
-0.41 C
1959
10.4 C
+0.80 C
1960
9.2 C
-0.39 C
1961
9.1 C
-0.49 C
1962
8.2 C
-1.31 C
1963
8.0 C
-1.57 C
1964
8.6 C
-1.00 C
1965
8.3 C
-1.23 C
1966
8.4 C
-1.15 C
1967
8.3 C
-1.29 C
1968
8.9 C
-0.62 C
1969
9.2 C
-0.34 C
1970
10.1 C
+0.54 C
1971
10.0 C
+0.48 C
1972
9.2 C
-0.34 C
1973
10.3 C
+0.70 C
1974
9.0 C
-0.54 C
1975
10.1 C
+0.58 C
1976
8.4 C
-1.12 C
1977
8.8 C
-0.78 C
1978
9.0 C
-0.53 C
The annual mean temperature here has fallen by 0.4 C (0.2 to 0.6) per decade over 1939 to 1978. In Fahrenheit: 0.7 F (0.4 to 1.1) per decade. The slope is a straight line fitted to 37 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Port Clinton
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.4 C (-0.6 to -0.2) per decade
-0.7 F (-1.1 to -0.4) per decade
1939 to 1978
37
Fall
Mean daily maximum
-0.03 C (-0.22 to 0.15) per decade
-0.1 F (-0.4 to 0.3) per decade
1939 to 1978
37
Not clearly different from zero
Mean daily minimum
-0.8 C (-1.1 to -0.5) per decade
-1.4 F (-2.0 to -0.8) per decade
1939 to 1978
37
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
1938 to 1979
Yearly extremes at Port Clinton: 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)
1966
35.6 C (96.1 F)
42
Coldest night (TNn)
-30.0 C (-22.0 F)
1961
-20.6 C (-5.1 F)
42
Wettest day (Rx1day)
120.1 mm (4.7 in)
1942
69.3 mm (2.7 in)
42
Wettest five days (Rx5day)
173.4 mm (6.8 in)
1959
106.7 mm (4.2 in)
42
Longest dry spell (CDD)
36 days
1955
17 days
42
Hottest day (TXx)
The hottest day of the year at Port Clinton, 1938 to 1979. The record is 40.0 C (104.0 F) in 1966, marked on the chart; the median year is 35.6 C (96.1 F).
Hottest day (TXx) at Port Clinton by year
Year
Hottest day (TXx)
1938
30.0 C (86.0 F)
1939
35.6 C (96.1 F)
1940
36.7 C (98.1 F)
1941
36.7 C (98.1 F)
1942
34.4 C (93.9 F)
1943
35.0 C (95.0 F)
1944
36.7 C (98.1 F)
1945
34.4 C (93.9 F)
1946
35.0 C (95.0 F)
1947
35.0 C (95.0 F)
1948
37.2 C (99.0 F)
1949
37.2 C (99.0 F)
1950
34.4 C (93.9 F)
1951
33.9 C (93.0 F)
1952
37.8 C (100.0 F)
1953
38.3 C (100.9 F)
1954
37.8 C (100.0 F)
1955
36.7 C (98.1 F)
1956
35.6 C (96.1 F)
1957
37.8 C (100.0 F)
1958
33.3 C (91.9 F)
1959
36.1 C (97.0 F)
1960
32.8 C (91.0 F)
1961
34.4 C (93.9 F)
1962
35.0 C (95.0 F)
1963
35.6 C (96.1 F)
1964
35.6 C (96.1 F)
1965
35.6 C (96.1 F)
1966
40.0 C (104.0 F)
1967
34.4 C (93.9 F)
1968
35.6 C (96.1 F)
1969
35.6 C (96.1 F)
1970
35.6 C (96.1 F)
1971
35.6 C (96.1 F)
1972
35.0 C (95.0 F)
1973
37.8 C (100.0 F)
1974
34.4 C (93.9 F)
1975
36.1 C (97.0 F)
1976
33.9 C (93.0 F)
1977
34.4 C (93.9 F)
1978
35.6 C (96.1 F)
1979
32.8 C (91.0 F)
Coldest night (TNn)
The coldest night of the year at Port Clinton, 1938 to 1979. The record is -30.0 C (-22.0 F) in 1961, marked on the chart; the median year is -20.6 C (-5.1 F).
Coldest night (TNn) at Port Clinton by year
Year
Coldest night (TNn)
1938
-16.7 C (1.9 F)
1939
-16.1 C (3.0 F)
1940
-17.2 C (1.0 F)
1941
-15.0 C (5.0 F)
1942
-23.3 C (-9.9 F)
1943
-24.4 C (-11.9 F)
1944
-17.8 C (0.0 F)
1945
-18.9 C (-2.0 F)
1946
-16.7 C (1.9 F)
1947
-16.7 C (1.9 F)
1948
-23.3 C (-9.9 F)
1949
-17.8 C (0.0 F)
1950
-21.1 C (-6.0 F)
1951
-23.3 C (-9.9 F)
1952
-14.4 C (6.1 F)
1953
-13.9 C (7.0 F)
1954
-22.2 C (-8.0 F)
1955
-16.7 C (1.9 F)
1956
-12.2 C (10.0 F)
1957
-21.1 C (-6.0 F)
1958
-21.1 C (-6.0 F)
1959
-19.4 C (-2.9 F)
1960
-17.8 C (0.0 F)
1961
-30.0 C (-22.0 F)
1962
-20.6 C (-5.1 F)
1963
-27.2 C (-17.0 F)
1964
-23.3 C (-9.9 F)
1965
-22.8 C (-9.0 F)
1966
-23.3 C (-9.9 F)
1967
-23.9 C (-11.0 F)
1968
-24.4 C (-11.9 F)
1969
-19.4 C (-2.9 F)
1970
-22.2 C (-8.0 F)
1971
-20.6 C (-5.1 F)
1972
-19.4 C (-2.9 F)
1973
-17.8 C (0.0 F)
1974
-20.0 C (-4.0 F)
1975
-18.9 C (-2.0 F)
1976
-21.1 C (-6.0 F)
1977
-27.2 C (-17.0 F)
1978
-20.6 C (-5.1 F)
1979
-23.3 C (-9.9 F)
Wettest day (Rx1day)
The wettest day of the year at Port Clinton, 1938 to 1979. The record is 120.1 mm (4.7 in) in 1942, marked on the chart; the median year is 69.3 mm (2.7 in).
Wettest day (Rx1day) at Port Clinton by year
Year
Wettest day (Rx1day)
1938
55.9 mm (2.2 in)
1939
51.1 mm (2.0 in)
1940
48.5 mm (1.9 in)
1941
44.5 mm (1.8 in)
1942
120.1 mm (4.7 in)
1943
86.4 mm (3.4 in)
1944
53.1 mm (2.1 in)
1945
73.7 mm (2.9 in)
1946
43.2 mm (1.7 in)
1947
110.7 mm (4.4 in)
1948
55.9 mm (2.2 in)
1949
63.0 mm (2.5 in)
1950
82.3 mm (3.2 in)
1951
55.9 mm (2.2 in)
1952
111.8 mm (4.4 in)
1953
81.3 mm (3.2 in)
1954
41.1 mm (1.6 in)
1955
81.0 mm (3.2 in)
1956
68.6 mm (2.7 in)
1957
62.7 mm (2.5 in)
1958
50.8 mm (2.0 in)
1959
70.6 mm (2.8 in)
1960
87.9 mm (3.5 in)
1961
111.3 mm (4.4 in)
1962
76.5 mm (3.0 in)
1963
76.7 mm (3.0 in)
1964
51.1 mm (2.0 in)
1965
69.9 mm (2.8 in)
1966
54.9 mm (2.2 in)
1967
96.5 mm (3.8 in)
1968
82.3 mm (3.2 in)
1969
87.4 mm (3.4 in)
1970
73.7 mm (2.9 in)
1971
75.7 mm (3.0 in)
1972
68.6 mm (2.7 in)
1973
93.2 mm (3.7 in)
1974
50.8 mm (2.0 in)
1975
66.0 mm (2.6 in)
1976
116.8 mm (4.6 in)
1977
48.5 mm (1.9 in)
1978
67.6 mm (2.7 in)
1979
66.0 mm (2.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Port Clinton, 1938 to 1979. The record is 173.4 mm (6.8 in) in 1959, marked on the chart; the median year is 106.7 mm (4.2 in).
Wettest five days (Rx5day) at Port Clinton by year
Year
Wettest five days (Rx5day)
1938
99.0 mm (3.9 in)
1939
83.0 mm (3.3 in)
1940
123.9 mm (4.9 in)
1941
58.1 mm (2.3 in)
1942
168.9 mm (6.6 in)
1943
110.7 mm (4.4 in)
1944
106.7 mm (4.2 in)
1945
172.7 mm (6.8 in)
1946
85.1 mm (3.4 in)
1947
124.0 mm (4.9 in)
1948
83.8 mm (3.3 in)
1949
83.8 mm (3.3 in)
1950
133.6 mm (5.3 in)
1951
71.4 mm (2.8 in)
1952
156.8 mm (6.2 in)
1953
112.3 mm (4.4 in)
1954
55.1 mm (2.2 in)
1955
126.5 mm (5.0 in)
1956
68.6 mm (2.7 in)
1957
115.5 mm (4.5 in)
1958
97.8 mm (3.9 in)
1959
173.4 mm (6.8 in)
1960
125.3 mm (4.9 in)
1961
135.4 mm (5.3 in)
1962
92.2 mm (3.6 in)
1963
98.3 mm (3.9 in)
1964
89.8 mm (3.5 in)
1965
86.4 mm (3.4 in)
1966
60.2 mm (2.4 in)
1967
105.7 mm (4.2 in)
1968
106.6 mm (4.2 in)
1969
159.0 mm (6.3 in)
1970
111.2 mm (4.4 in)
1971
143.9 mm (5.7 in)
1972
97.8 mm (3.9 in)
1973
102.1 mm (4.0 in)
1974
78.3 mm (3.1 in)
1975
145.8 mm (5.7 in)
1976
139.9 mm (5.5 in)
1977
85.3 mm (3.4 in)
1978
136.4 mm (5.4 in)
1979
106.7 mm (4.2 in)
Longest dry spell (CDD)
The longest dry spell of the year at Port Clinton, 1938 to 1979. The record is 36 days in 1955, marked on the chart; the median year is 17 days.
Longest dry spell (CDD) at Port Clinton by year
Year
Longest dry spell (CDD)
1938
13 days
1939
25 days
1940
17 days
1941
21 days
1942
21 days
1943
26 days
1944
13 days
1945
15 days
1946
21 days
1947
25 days
1948
14 days
1949
12 days
1950
12 days
1951
10 days
1952
16 days
1953
18 days
1954
13 days
1955
36 days
1956
8 days
1957
17 days
1958
20 days
1959
17 days
1960
19 days
1961
11 days
1962
19 days
1963
31 days
1964
30 days
1965
17 days
1966
20 days
1967
19 days
1968
26 days
1969
17 days
1970
18 days
1971
18 days
1972
11 days
1973
18 days
1974
13 days
1975
16 days
1976
17 days
1977
15 days
1978
18 days
1979
11 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
37 years with a frost
Across 37 years with a frost, the median last spring frost at Port Clinton falls on 11 May and the median first autumn frost on 30 September, which leaves a median of 143 days between them.
Fitted over all years, the growing season changes by -4.3 days per decade at this station.
Frost dates and growing season at Port Clinton
Measure
Median, all years
Earliest period
Recent period (1946 to 1978)
Recent against earliest
Fitted trend
Last spring frost
11 May
n/a
11 May
n/a
+2.5 days per decade
First autumn frost
30 September
n/a
30 September
n/a
-1.8 days per decade
Growing days
143 days
n/a
141 days
n/a
-4.3 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
38 years, 1939 to 1978
A day with at least 70.7 mm (2.8 in) of rain is expected about once in 2 years. A day with at least 139.2 mm (5.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Port Clinton: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
70.7 mm (2.8 in)
5 years
90.6 mm (3.6 in)
10 years
103.1 mm (4.1 in)
25 years
118.2 mm (4.7 in)
50 years
129.0 mm (5.1 in)
Longer than the 38 years of record
100 years
139.2 mm (5.5 in)
Longer than the 38 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, 38 years of values from 1939 to 1978.
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: 120.1 mm (4.7 in) in 1942; 116.8 mm (4.6 in) in 1976; 111.8 mm (4.4 in) in 1952.
Download the Data
Data for Port Clinton standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Port Clinton 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.