Record envelope, standing records and threshold days for Octoraro Lake (USC00366508), Pennsylvania, United States, with 49 years of record.
Key Facts for Octoraro Lake
Octoraro Lake (USC00366508) is a weather station in Pennsylvania, United States at 39.80 latitude and -76.04 longitude, 79 m (260 ft) above sea level.
The station reports from 1978 to 2026, 49 years of record.
1,464 records set at Octoraro Lake still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Octoraro Lake set a daily record precipitation of 26.2 mm (1.0 in) on 28 July 2026.
About the Station
Location: Pennsylvania, United States, 39.80 latitude, -76.04 longitude.
Elevation: 79 m (260 ft).
Period of record: 1978 to 2026, 49 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
19 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 Octoraro Lake. The lines show the 2026 daily maximum and minimum. 19 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Octoraro Lake, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
22.2 C (72.0 F)
-28.3 C (-18.9 F)
13.3 C (55.9 F)
-18.3 C (-0.9 F)
Feb
25.6 C (78.1 F)
-27.2 C (-17.0 F)
14.4 C (57.9 F)
-15.0 C (5.0 F)
Mar
32.8 C (91.0 F)
-20.0 C (-4.0 F)
27.2 C (81.0 F)
-5.6 C (21.9 F)
Apr
35.0 C (95.0 F)
-12.2 C (10.0 F)
31.1 C (88.0 F)
-5.0 C (23.0 F)
May
35.0 C (95.0 F)
-5.0 C (23.0 F)
34.4 C (93.9 F)
1.7 C (35.1 F)
Jun
37.2 C (99.0 F)
1.1 C (34.0 F)
34.4 C (93.9 F)
7.2 C (45.0 F)
Jul
39.4 C (102.9 F)
5.6 C (42.1 F)
38.9 C (102.0 F)
11.7 C (53.1 F)
Aug
40.0 C (104.0 F)
2.2 C (36.0 F)
23.9 C (75.0 F)
14.4 C (57.9 F)
Sep
36.1 C (97.0 F)
-0.6 C (30.9 F)
n/a
n/a
Oct
33.3 C (91.9 F)
-11.1 C (12.0 F)
n/a
n/a
Nov
27.2 C (81.0 F)
-11.7 C (10.9 F)
n/a
n/a
Dec
23.9 C (75.0 F)
-20.0 C (-4.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Octoraro Lake still stand. 1992 holds the most, with 68.
Standing records at Octoraro Lake by the year they were set
Year set
Standing records
1978
21
1979
39
1980
22
1981
22
1982
39
1983
34
1984
34
1985
32
1986
24
1987
19
1988
24
1989
40
1990
39
1991
46
1992
68
1993
40
1994
17
1995
38
1996
34
1997
46
1998
37
1999
50
2000
40
2001
43
2002
54
2003
28
2004
19
2005
16
2006
12
2007
27
2008
14
2009
16
2010
20
2011
23
2012
24
2013
21
2014
39
2015
43
2016
22
2017
34
2018
32
2019
21
2020
25
2021
12
2022
22
2023
25
2024
20
2025
21
2026
26
All-Time Record Progression
2 new records
2 all-time records were set at Octoraro Lake between 13 February 2014 and 23 January 2016. Each dot is a new record.
When Octoraro Lake set new all-time records
Date
Kind
Detail
2014-02-13
Record snow depth
Record snow depth 43.2 cm (17.0 in)
2016-01-23
Record snow depth
Record snow depth 50.8 cm (20.0 in)
Wettest Day of Each Month
Sep: 173.2 mm (6.8 in)
The wettest day on record for each calendar month at Octoraro Lake. The most was 173.2 mm (6.8 in) on 17 September 1999.
Record daily precipitation for each month at Octoraro Lake
Month
Record daily precipitation (mm)
Date
Jan
79.5 mm (3.1 in)
9 January 2024
Feb
68.6 mm (2.7 in)
17 February 2003
Mar
100.3 mm (3.9 in)
22 March 2000
Apr
125.0 mm (4.9 in)
30 April 2014
May
63.5 mm (2.5 in)
30 May 1990
Jun
96.5 mm (3.8 in)
15 June 2004
Jul
89.4 mm (3.5 in)
3 July 1978
Aug
128.3 mm (5.1 in)
4 August 2020
Sep
173.2 mm (6.8 in)
17 September 1999
Oct
133.1 mm (5.2 in)
8 October 2005
Nov
80.3 mm (3.2 in)
9 November 1996
Dec
88.6 mm (3.5 in)
13 December 1983
Period of Record Coverage
1978 to 2026
Complete yearUnder 90 percent of days
49 years of record at Octoraro Lake, 1978 to 2026. 8 years have data for under 90 percent of days and are left out of rankings: 1978, 1980, 1982, 1986, 1995, 2003, 2021, 2026.
Cooler than the station meanWarmer than the station mean
One stripe for each of 38 complete years at Octoraro Lake, 1983 to 2025. Blue stripes are years cooler than the station's own mean of 11.7 C (53.1 F); red stripes are warmer. The coolest year was 1992, at 10.1 C (50.1 F), and the warmest was 2024, at 12.9 C (55.2 F). The strongest colour marks a difference of 1.7 C (3.1 F).
Annual mean temperature at Octoraro Lake as warming stripes, 1983 to 2025
Year
Annual mean temperature
Difference from the station mean
1983
11.6 C
-0.15 C
1984
11.4 C
-0.34 C
1985
11.8 C
+0.08 C
1987
11.9 C
+0.17 C
1988
11.5 C
-0.24 C
1989
11.1 C
-0.63 C
1990
12.6 C
+0.91 C
1991
11.9 C
+0.13 C
1992
10.1 C
-1.66 C
1993
11.1 C
-0.62 C
1996
10.8 C
-0.93 C
1997
10.7 C
-1.01 C
1998
12.2 C
+0.49 C
1999
11.6 C
-0.13 C
2000
11.0 C
-0.72 C
2001
12.3 C
+0.53 C
2002
12.5 C
+0.80 C
2004
11.4 C
-0.32 C
2005
11.4 C
-0.29 C
2006
12.2 C
+0.51 C
2007
11.6 C
-0.11 C
2008
11.5 C
-0.23 C
2009
11.2 C
-0.50 C
2010
12.0 C
+0.25 C
2011
12.2 C
+0.49 C
2012
12.8 C
+1.08 C
2013
11.4 C
-0.35 C
2014
10.4 C
-1.37 C
2015
11.6 C
-0.10 C
2016
12.2 C
+0.45 C
2017
12.4 C
+0.70 C
2018
11.8 C
+0.05 C
2019
12.0 C
+0.22 C
2020
12.4 C
+0.65 C
2022
11.8 C
+0.07 C
2023
12.8 C
+1.04 C
2024
12.9 C
+1.18 C
2025
11.7 C
+0.01 C
The annual mean temperature here has risen by 0.19 C (0.02 to 0.35) per decade over 1983 to 2025. In Fahrenheit: 0.34 F (0.04 to 0.64) per decade. The slope is a straight line fitted to 38 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Octoraro Lake
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.19 C (0.02 to 0.35) per decade
0.34 F (0.04 to 0.64) per decade
1983 to 2025
38
Rise
Mean daily maximum
-0.30 C (-0.55 to -0.04) per decade
-0.5 F (-1.0 to -0.1) per decade
1983 to 2025
38
Fall
Mean daily minimum
0.7 C (0.4 to 0.9) per decade
1.2 F (0.8 to 1.7) per decade
1983 to 2025
38
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
1978 to 2026
Yearly extremes at Octoraro Lake: 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)
2001
35.6 C (96.1 F)
49
Coldest night (TNn)
-28.3 C (-18.9 F)
1984
-18.3 C (-0.9 F)
49
Wettest day (Rx1day)
173.2 mm (6.8 in)
1999
69.9 mm (2.8 in)
49
Wettest five days (Rx5day)
226.5 mm (8.9 in)
1999
105.5 mm (4.2 in)
49
Longest dry spell (CDD)
39 days
2024
18 days
49
Hottest day (TXx)
The hottest day of the year at Octoraro Lake, 1978 to 2026. The record is 40.0 C (104.0 F) in 2001, marked on the chart; the median year is 35.6 C (96.1 F).
Hottest day (TXx) at Octoraro Lake by year
Year
Hottest day (TXx)
1978
34.4 C (93.9 F)
1979
35.0 C (95.0 F)
1980
37.2 C (99.0 F)
1981
34.4 C (93.9 F)
1982
35.6 C (96.1 F)
1983
37.2 C (99.0 F)
1984
35.0 C (95.0 F)
1985
35.6 C (96.1 F)
1986
36.1 C (97.0 F)
1987
37.2 C (99.0 F)
1988
37.8 C (100.0 F)
1989
34.4 C (93.9 F)
1990
36.7 C (98.1 F)
1991
37.8 C (100.0 F)
1992
35.6 C (96.1 F)
1993
37.2 C (99.0 F)
1994
37.2 C (99.0 F)
1995
39.4 C (102.9 F)
1996
34.4 C (93.9 F)
1997
37.8 C (100.0 F)
1998
35.0 C (95.0 F)
1999
37.8 C (100.0 F)
2000
35.0 C (95.0 F)
2001
40.0 C (104.0 F)
2002
39.4 C (102.9 F)
2003
33.3 C (91.9 F)
2004
32.2 C (90.0 F)
2005
35.6 C (96.1 F)
2006
35.6 C (96.1 F)
2007
35.0 C (95.0 F)
2008
35.0 C (95.0 F)
2009
33.3 C (91.9 F)
2010
36.7 C (98.1 F)
2011
37.8 C (100.0 F)
2012
37.2 C (99.0 F)
2013
35.0 C (95.0 F)
2014
32.8 C (91.0 F)
2015
33.3 C (91.9 F)
2016
35.6 C (96.1 F)
2017
33.9 C (93.0 F)
2018
35.0 C (95.0 F)
2019
34.4 C (93.9 F)
2020
35.0 C (95.0 F)
2021
33.3 C (91.9 F)
2022
36.7 C (98.1 F)
2023
35.0 C (95.0 F)
2024
37.8 C (100.0 F)
2025
36.7 C (98.1 F)
2026
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at Octoraro Lake, 1978 to 2026. The record is -28.3 C (-18.9 F) in 1984, marked on the chart; the median year is -18.3 C (-0.9 F).
Coldest night (TNn) at Octoraro Lake by year
Year
Coldest night (TNn)
1978
-18.9 C (-2.0 F)
1979
-24.4 C (-11.9 F)
1980
-16.7 C (1.9 F)
1981
-22.2 C (-8.0 F)
1982
-23.9 C (-11.0 F)
1983
-17.2 C (1.0 F)
1984
-28.3 C (-18.9 F)
1985
-17.2 C (1.0 F)
1986
-19.4 C (-2.9 F)
1987
-25.6 C (-14.1 F)
1988
-22.8 C (-9.0 F)
1989
-20.0 C (-4.0 F)
1990
-13.3 C (8.1 F)
1991
-17.8 C (0.0 F)
1992
-18.3 C (-0.9 F)
1993
-19.4 C (-2.9 F)
1994
-25.6 C (-14.1 F)
1995
-17.8 C (0.0 F)
1996
-27.2 C (-17.0 F)
1997
-18.9 C (-2.0 F)
1998
-16.1 C (3.0 F)
1999
-17.8 C (0.0 F)
2000
-23.9 C (-11.0 F)
2001
-16.7 C (1.9 F)
2002
-18.9 C (-2.0 F)
2003
-18.3 C (-0.9 F)
2004
-19.4 C (-2.9 F)
2005
-17.8 C (0.0 F)
2006
-13.3 C (8.1 F)
2007
-16.7 C (1.9 F)
2008
-12.2 C (10.0 F)
2009
-16.7 C (1.9 F)
2010
-14.4 C (6.1 F)
2011
-18.3 C (-0.9 F)
2012
-11.1 C (12.0 F)
2013
-15.0 C (5.0 F)
2014
-20.0 C (-4.0 F)
2015
-20.6 C (-5.1 F)
2016
-16.7 C (1.9 F)
2017
-17.8 C (0.0 F)
2018
-18.3 C (-0.9 F)
2019
-18.9 C (-2.0 F)
2020
-11.7 C (10.9 F)
2021
-10.6 C (12.9 F)
2022
-16.1 C (3.0 F)
2023
-11.7 C (10.9 F)
2024
-13.3 C (8.1 F)
2025
-18.3 C (-0.9 F)
2026
-18.3 C (-0.9 F)
Wettest day (Rx1day)
The wettest day of the year at Octoraro Lake, 1978 to 2026. The record is 173.2 mm (6.8 in) in 1999, marked on the chart; the median year is 69.9 mm (2.8 in).
Wettest day (Rx1day) at Octoraro Lake by year
Year
Wettest day (Rx1day)
1978
89.4 mm (3.5 in)
1979
118.6 mm (4.7 in)
1980
51.1 mm (2.0 in)
1981
29.2 mm (1.1 in)
1982
51.3 mm (2.0 in)
1983
88.6 mm (3.5 in)
1984
51.1 mm (2.0 in)
1985
157.7 mm (6.2 in)
1986
41.7 mm (1.6 in)
1987
149.9 mm (5.9 in)
1988
61.0 mm (2.4 in)
1989
55.9 mm (2.2 in)
1990
63.5 mm (2.5 in)
1991
41.9 mm (1.6 in)
1992
50.3 mm (2.0 in)
1993
56.1 mm (2.2 in)
1994
55.9 mm (2.2 in)
1995
54.1 mm (2.1 in)
1996
96.5 mm (3.8 in)
1997
51.6 mm (2.0 in)
1998
84.8 mm (3.3 in)
1999
173.2 mm (6.8 in)
2000
100.3 mm (3.9 in)
2001
55.9 mm (2.2 in)
2002
47.8 mm (1.9 in)
2003
112.8 mm (4.4 in)
2004
96.5 mm (3.8 in)
2005
133.1 mm (5.2 in)
2006
87.9 mm (3.5 in)
2007
64.0 mm (2.5 in)
2008
73.4 mm (2.9 in)
2009
97.8 mm (3.9 in)
2010
116.8 mm (4.6 in)
2011
121.4 mm (4.8 in)
2012
106.2 mm (4.2 in)
2013
69.9 mm (2.8 in)
2014
125.0 mm (4.9 in)
2015
51.1 mm (2.0 in)
2016
58.7 mm (2.3 in)
2017
74.4 mm (2.9 in)
2018
59.7 mm (2.4 in)
2019
55.4 mm (2.2 in)
2020
128.3 mm (5.1 in)
2021
156.2 mm (6.1 in)
2022
75.4 mm (3.0 in)
2023
56.1 mm (2.2 in)
2024
81.3 mm (3.2 in)
2025
58.2 mm (2.3 in)
2026
50.0 mm (2.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Octoraro Lake, 1978 to 2026. The record is 226.5 mm (8.9 in) in 1999, marked on the chart; the median year is 105.5 mm (4.2 in).
Wettest five days (Rx5day) at Octoraro Lake by year
Year
Wettest five days (Rx5day)
1978
100.2 mm (3.9 in)
1979
163.6 mm (6.4 in)
1980
98.4 mm (3.9 in)
1981
50.5 mm (2.0 in)
1982
85.1 mm (3.4 in)
1983
120.7 mm (4.8 in)
1984
68.2 mm (2.7 in)
1985
189.2 mm (7.4 in)
1986
76.0 mm (3.0 in)
1987
210.6 mm (8.3 in)
1988
101.6 mm (4.0 in)
1989
105.5 mm (4.2 in)
1990
92.0 mm (3.6 in)
1991
65.0 mm (2.6 in)
1992
69.7 mm (2.7 in)
1993
87.6 mm (3.4 in)
1994
94.7 mm (3.7 in)
1995
81.6 mm (3.2 in)
1996
120.4 mm (4.7 in)
1997
76.0 mm (3.0 in)
1998
102.6 mm (4.0 in)
1999
226.5 mm (8.9 in)
2000
118.3 mm (4.7 in)
2001
70.2 mm (2.8 in)
2002
67.6 mm (2.7 in)
2003
162.3 mm (6.4 in)
2004
134.4 mm (5.3 in)
2005
183.9 mm (7.2 in)
2006
208.2 mm (8.2 in)
2007
107.2 mm (4.2 in)
2008
104.7 mm (4.1 in)
2009
148.7 mm (5.9 in)
2010
213.8 mm (8.4 in)
2011
172.2 mm (6.8 in)
2012
152.8 mm (6.0 in)
2013
129.3 mm (5.1 in)
2014
142.8 mm (5.6 in)
2015
83.6 mm (3.3 in)
2016
111.5 mm (4.4 in)
2017
76.4 mm (3.0 in)
2018
128.3 mm (5.1 in)
2019
79.3 mm (3.1 in)
2020
160.3 mm (6.3 in)
2021
172.0 mm (6.8 in)
2022
106.0 mm (4.2 in)
2023
86.0 mm (3.4 in)
2024
110.0 mm (4.3 in)
2025
86.4 mm (3.4 in)
2026
70.8 mm (2.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Octoraro Lake, 1978 to 2026. The record is 39 days in 2024, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Octoraro Lake by year
Year
Longest dry spell (CDD)
1978
21 days
1979
12 days
1980
22 days
1981
25 days
1982
15 days
1983
19 days
1984
12 days
1985
21 days
1986
20 days
1987
23 days
1988
29 days
1989
14 days
1990
12 days
1991
23 days
1992
17 days
1993
12 days
1994
20 days
1995
25 days
1996
10 days
1997
23 days
1998
17 days
1999
18 days
2000
21 days
2001
34 days
2002
13 days
2003
12 days
2004
16 days
2005
20 days
2006
19 days
2007
18 days
2008
15 days
2009
14 days
2010
20 days
2011
15 days
2012
15 days
2013
14 days
2014
12 days
2015
20 days
2016
18 days
2017
24 days
2018
11 days
2019
18 days
2020
15 days
2021
15 days
2022
12 days
2023
26 days
2024
39 days
2025
14 days
2026
20 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
38 years with a frost
Across 38 years with a frost, the median last spring frost at Octoraro Lake falls on 27 April and the median first autumn frost on 20 October, which leaves a median of 173 days between them.
Fitted over all years, the growing season changes by +7.8 days per decade at this station.
Frost dates and growing season at Octoraro Lake
Measure
Median, all years
Earliest period
Recent period (1992 to 2025)
Recent against earliest
Fitted trend
Last spring frost
27 April
n/a
27 April
n/a
-3.6 days per decade
First autumn frost
20 October
n/a
20 October
n/a
+4.2 days per decade
Growing days
173 days
n/a
178 days
n/a
+7.8 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
47 years, 1978 to 2025
A day with at least 72.5 mm (2.9 in) of rain is expected about once in 2 years. A day with at least 209.1 mm (8.2 in) of rain is expected about once in 100 years.
Rainfall return levels at Octoraro Lake: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
72.5 mm (2.9 in)
5 years
102.7 mm (4.0 in)
10 years
125.0 mm (4.9 in)
25 years
156.2 mm (6.1 in)
50 years
181.7 mm (7.2 in)
Longer than the 47 years of record
100 years
209.1 mm (8.2 in)
Longer than the 47 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, 47 years of values from 1978 to 2025.
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: 173.2 mm (6.8 in) in 1999; 157.7 mm (6.2 in) in 1985; 149.9 mm (5.9 in) in 1987.
Download the Data
Data for Octoraro Lake standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Octoraro Lake 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.