Record envelope, standing records and threshold days for Catoctin Mtn Park (USC00181530), Maryland, United States, with 45 years of record.
Key Facts for Catoctin Mtn Park
Catoctin Mtn Park (USC00181530) is a weather station in Maryland, United States at 39.65 latitude and -77.48 longitude, 491 m (1,610 ft) above sea level.
The station reports from 1968 to 2012, 45 years of record.
1,464 records set at Catoctin Mtn Park still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Catoctin Mtn Park set a daily record high maximum temperature of 16.7 C (62.1 F) on 31 January 2012.
About the Station
Location: Maryland, United States, 39.65 latitude, -77.48 longitude.
Elevation: 491 m (1,610 ft).
Period of record: 1968 to 2012, 45 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 Catoctin Mtn Park. 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 Catoctin Mtn Park, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
20.6 C (69.1 F)
-27.8 C (-18.0 F)
n/a
n/a
Feb
23.9 C (75.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Mar
30.0 C (86.0 F)
-17.2 C (1.0 F)
n/a
n/a
Apr
32.8 C (91.0 F)
-11.1 C (12.0 F)
n/a
n/a
May
33.3 C (91.9 F)
-3.3 C (26.1 F)
n/a
n/a
Jun
34.4 C (93.9 F)
1.1 C (34.0 F)
n/a
n/a
Jul
38.3 C (100.9 F)
5.0 C (41.0 F)
n/a
n/a
Aug
34.4 C (93.9 F)
2.8 C (37.0 F)
n/a
n/a
Sep
33.3 C (91.9 F)
-5.0 C (23.0 F)
n/a
n/a
Oct
31.1 C (88.0 F)
-8.9 C (16.0 F)
n/a
n/a
Nov
27.8 C (82.0 F)
-14.4 C (6.1 F)
n/a
n/a
Dec
23.9 C (75.0 F)
-23.9 C (-11.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Catoctin Mtn Park still stand. 1979 holds the most, with 55.
Standing records at Catoctin Mtn Park by the year they were set
Year set
Standing records
1968
34
1969
29
1970
35
1971
36
1972
42
1973
39
1974
33
1975
32
1976
41
1977
43
1978
23
1979
55
1980
27
1981
20
1982
28
1983
39
1984
41
1985
29
1986
34
1987
26
1988
54
1989
48
1990
48
1991
26
1992
27
1993
37
1994
25
1995
29
1996
27
1997
22
1998
55
1999
21
2000
32
2001
29
2002
42
2003
47
2004
22
2005
17
2006
32
2007
32
2008
19
2009
25
2010
40
2011
21
2012
1
All-Time Record Progression
1 new records
1 all-time records were set at Catoctin Mtn Park between 3 July 2011 and 3 July 2011. Each dot is a new record.
When Catoctin Mtn Park set new all-time records
Date
Kind
Detail
2011-07-03
Record high maximum temperature
Record high maximum temperature 38.3 C (100.9 F)
Wettest Day of Each Month
Sep: 160.0 mm (6.3 in)
The wettest day on record for each calendar month at Catoctin Mtn Park. The most was 160.0 mm (6.3 in) on 6 September 1979.
Record daily precipitation for each month at Catoctin Mtn Park
Month
Record daily precipitation (mm)
Date
Jan
106.7 mm (4.2 in)
10 January 1987
Feb
133.9 mm (5.3 in)
14 February 1984
Mar
93.2 mm (3.7 in)
19 March 1975
Apr
77.0 mm (3.0 in)
4 April 1987
May
133.9 mm (5.3 in)
16 May 2003
Jun
154.4 mm (6.1 in)
22 June 1972
Jul
103.6 mm (4.1 in)
5 July 1989
Aug
120.7 mm (4.8 in)
11 August 1984
Sep
160.0 mm (6.3 in)
6 September 1979
Oct
94.5 mm (3.7 in)
9 October 1976
Nov
102.6 mm (4.0 in)
28 November 1993
Dec
87.1 mm (3.4 in)
11 December 1992
Period of Record Coverage
1968 to 2012
Complete yearUnder 90 percent of days
45 years of record at Catoctin Mtn Park, 1968 to 2012. 7 years have data for under 90 percent of days and are left out of rankings: 1991, 2006, 2007, 2008, 2010, 2011, 2012.
Cooler than the station meanWarmer than the station mean
One stripe for each of 35 complete years at Catoctin Mtn Park, 1968 to 2005. Blue stripes are years cooler than the station's own mean of 10.8 C (51.5 F); red stripes are warmer. The coolest year was 1969, at 9.6 C (49.3 F), and the warmest was 1998, at 12.8 C (55.0 F). The strongest colour marks a difference of 2.0 C (3.6 F).
Annual mean temperature at Catoctin Mtn Park as warming stripes, 1968 to 2005
Year
Annual mean temperature
Difference from the station mean
1968
10.0 C
-0.85 C
1969
9.6 C
-1.23 C
1970
10.3 C
-0.51 C
1971
10.8 C
-0.04 C
1972
10.1 C
-0.72 C
1973
11.5 C
+0.63 C
1974
10.9 C
+0.09 C
1975
10.9 C
+0.01 C
1976
10.2 C
-0.60 C
1978
9.7 C
-1.18 C
1979
10.0 C
-0.84 C
1980
10.3 C
-0.55 C
1981
10.3 C
-0.56 C
1982
10.6 C
-0.20 C
1983
10.8 C
-0.02 C
1984
10.8 C
-0.07 C
1985
10.8 C
-0.04 C
1986
11.0 C
+0.13 C
1987
11.3 C
+0.47 C
1988
10.7 C
-0.14 C
1989
10.4 C
-0.43 C
1990
12.1 C
+1.29 C
1992
10.2 C
-0.61 C
1993
10.9 C
+0.01 C
1994
11.0 C
+0.19 C
1996
10.4 C
-0.40 C
1997
10.9 C
+0.06 C
1998
12.8 C
+1.92 C
1999
12.0 C
+1.12 C
2000
11.1 C
+0.27 C
2001
12.0 C
+1.11 C
2002
12.2 C
+1.36 C
2003
10.1 C
-0.73 C
2004
11.4 C
+0.59 C
2005
11.5 C
+0.62 C
The annual mean temperature here has risen by 0.4 C (0.2 to 0.6) per decade over 1968 to 2005. In Fahrenheit: 0.7 F (0.3 to 1.0) per decade. The slope is a straight line fitted to 35 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Catoctin Mtn Park
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.4 C (0.2 to 0.6) per decade
0.7 F (0.3 to 1.0) per decade
1968 to 2005
35
Rise
Mean daily maximum
0.4 C (0.2 to 0.6) per decade
0.8 F (0.4 to 1.2) per decade
1968 to 2005
35
Rise
Mean daily minimum
0.3 C (0.1 to 0.5) per decade
0.6 F (0.2 to 0.9) per decade
1968 to 2005
35
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
1968 to 2012
Yearly extremes at Catoctin Mtn Park: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
38.3 C (100.9 F)
2011
32.8 C (91.0 F)
45
Coldest night (TNn)
-27.8 C (-18.0 F)
1994
-18.3 C (-0.9 F)
45
Wettest day (Rx1day)
160.0 mm (6.3 in)
1979
73.7 mm (2.9 in)
45
Wettest five days (Rx5day)
294.8 mm (11.6 in)
1972
115.3 mm (4.5 in)
45
Longest dry spell (CDD)
27 days
1978
17 days
45
Hottest day (TXx)
The hottest day of the year at Catoctin Mtn Park, 1968 to 2012. The record is 38.3 C (100.9 F) in 2011, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Catoctin Mtn Park by year
Year
Hottest day (TXx)
1968
31.7 C (89.1 F)
1969
31.7 C (89.1 F)
1970
30.6 C (87.1 F)
1971
33.9 C (93.0 F)
1972
31.7 C (89.1 F)
1973
36.7 C (98.1 F)
1974
36.7 C (98.1 F)
1975
32.8 C (91.0 F)
1976
31.7 C (89.1 F)
1977
33.3 C (91.9 F)
1978
30.0 C (86.0 F)
1979
31.1 C (88.0 F)
1980
32.8 C (91.0 F)
1981
31.1 C (88.0 F)
1982
33.3 C (91.9 F)
1983
34.4 C (93.9 F)
1984
30.6 C (87.1 F)
1985
30.6 C (87.1 F)
1986
31.7 C (89.1 F)
1987
32.2 C (90.0 F)
1988
35.6 C (96.1 F)
1989
30.6 C (87.1 F)
1990
32.2 C (90.0 F)
1991
33.9 C (93.0 F)
1992
31.1 C (88.0 F)
1993
32.8 C (91.0 F)
1994
32.2 C (90.0 F)
1995
35.0 C (95.0 F)
1996
33.3 C (91.9 F)
1997
34.4 C (93.9 F)
1998
32.2 C (90.0 F)
1999
35.0 C (95.0 F)
2000
32.2 C (90.0 F)
2001
33.9 C (93.0 F)
2002
35.0 C (95.0 F)
2003
30.6 C (87.1 F)
2004
31.7 C (89.1 F)
2005
33.3 C (91.9 F)
2006
33.3 C (91.9 F)
2007
33.9 C (93.0 F)
2008
34.4 C (93.9 F)
2009
33.3 C (91.9 F)
2010
35.6 C (96.1 F)
2011
38.3 C (100.9 F)
2012
16.7 C (62.1 F)
Coldest night (TNn)
The coldest night of the year at Catoctin Mtn Park, 1968 to 2012. The record is -27.8 C (-18.0 F) in 1994, marked on the chart; the median year is -18.3 C (-0.9 F).
Coldest night (TNn) at Catoctin Mtn Park by year
Year
Coldest night (TNn)
1968
-20.6 C (-5.1 F)
1969
-18.9 C (-2.0 F)
1970
-22.8 C (-9.0 F)
1971
-18.9 C (-2.0 F)
1972
-21.7 C (-7.1 F)
1973
-18.3 C (-0.9 F)
1974
-12.8 C (9.0 F)
1975
-15.6 C (3.9 F)
1976
-18.9 C (-2.0 F)
1977
-24.4 C (-11.9 F)
1978
-17.8 C (0.0 F)
1979
-20.6 C (-5.1 F)
1980
-18.3 C (-0.9 F)
1981
-20.0 C (-4.0 F)
1982
-26.7 C (-16.1 F)
1983
-23.9 C (-11.0 F)
1984
-20.6 C (-5.1 F)
1985
-26.7 C (-16.1 F)
1986
-17.8 C (0.0 F)
1987
-17.2 C (1.0 F)
1988
-18.3 C (-0.9 F)
1989
-20.6 C (-5.1 F)
1990
-15.6 C (3.9 F)
1991
-13.9 C (7.0 F)
1992
-16.1 C (3.0 F)
1993
-18.9 C (-2.0 F)
1994
-27.8 C (-18.0 F)
1995
-20.0 C (-4.0 F)
1996
-19.4 C (-2.9 F)
1997
-18.9 C (-2.0 F)
1998
-13.3 C (8.1 F)
1999
-14.4 C (6.1 F)
2000
-16.1 C (3.0 F)
2001
-11.1 C (12.0 F)
2002
-12.2 C (10.0 F)
2003
-16.1 C (3.0 F)
2004
-18.9 C (-2.0 F)
2005
-16.7 C (1.9 F)
2006
-15.6 C (3.9 F)
2007
-18.9 C (-2.0 F)
2008
-15.6 C (3.9 F)
2009
-18.3 C (-0.9 F)
2010
-13.9 C (7.0 F)
2011
-12.2 C (10.0 F)
2012
-13.9 C (7.0 F)
Wettest day (Rx1day)
The wettest day of the year at Catoctin Mtn Park, 1968 to 2012. The record is 160.0 mm (6.3 in) in 1979, marked on the chart; the median year is 73.7 mm (2.9 in).
Wettest day (Rx1day) at Catoctin Mtn Park by year
Year
Wettest day (Rx1day)
1968
68.6 mm (2.7 in)
1969
73.7 mm (2.9 in)
1970
73.7 mm (2.9 in)
1971
52.8 mm (2.1 in)
1972
154.4 mm (6.1 in)
1973
102.1 mm (4.0 in)
1974
59.9 mm (2.4 in)
1975
106.7 mm (4.2 in)
1976
94.5 mm (3.7 in)
1977
49.8 mm (2.0 in)
1978
74.2 mm (2.9 in)
1979
160.0 mm (6.3 in)
1980
62.2 mm (2.4 in)
1981
80.8 mm (3.2 in)
1982
61.0 mm (2.4 in)
1983
65.8 mm (2.6 in)
1984
133.9 mm (5.3 in)
1985
61.5 mm (2.4 in)
1986
80.0 mm (3.1 in)
1987
106.7 mm (4.2 in)
1988
118.1 mm (4.6 in)
1989
103.6 mm (4.1 in)
1990
85.9 mm (3.4 in)
1991
32.3 mm (1.3 in)
1992
87.1 mm (3.4 in)
1993
102.6 mm (4.0 in)
1994
73.7 mm (2.9 in)
1995
72.4 mm (2.9 in)
1996
73.2 mm (2.9 in)
1997
57.4 mm (2.3 in)
1998
60.7 mm (2.4 in)
1999
62.2 mm (2.4 in)
2000
68.6 mm (2.7 in)
2001
44.2 mm (1.7 in)
2002
53.8 mm (2.1 in)
2003
133.9 mm (5.3 in)
2004
99.1 mm (3.9 in)
2005
90.2 mm (3.6 in)
2006
63.5 mm (2.5 in)
2007
52.1 mm (2.1 in)
2008
79.2 mm (3.1 in)
2009
50.5 mm (2.0 in)
2010
89.2 mm (3.5 in)
2011
37.3 mm (1.5 in)
2012
24.9 mm (1.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Catoctin Mtn Park, 1968 to 2012. The record is 294.8 mm (11.6 in) in 1972, marked on the chart; the median year is 115.3 mm (4.5 in).
Wettest five days (Rx5day) at Catoctin Mtn Park by year
Year
Wettest five days (Rx5day)
1968
106.4 mm (4.2 in)
1969
118.7 mm (4.7 in)
1970
93.3 mm (3.7 in)
1971
147.7 mm (5.8 in)
1972
294.8 mm (11.6 in)
1973
115.3 mm (4.5 in)
1974
71.9 mm (2.8 in)
1975
267.2 mm (10.5 in)
1976
127.3 mm (5.0 in)
1977
86.9 mm (3.4 in)
1978
171.5 mm (6.8 in)
1979
261.3 mm (10.3 in)
1980
89.9 mm (3.5 in)
1981
137.8 mm (5.4 in)
1982
91.0 mm (3.6 in)
1983
97.3 mm (3.8 in)
1984
201.3 mm (7.9 in)
1985
136.4 mm (5.4 in)
1986
80.0 mm (3.1 in)
1987
112.8 mm (4.4 in)
1988
198.9 mm (7.8 in)
1989
111.2 mm (4.4 in)
1990
133.9 mm (5.3 in)
1991
58.0 mm (2.3 in)
1992
138.2 mm (5.4 in)
1993
129.3 mm (5.1 in)
1994
149.9 mm (5.9 in)
1995
90.0 mm (3.5 in)
1996
122.1 mm (4.8 in)
1997
110.0 mm (4.3 in)
1998
94.7 mm (3.7 in)
1999
94.2 mm (3.7 in)
2000
98.3 mm (3.9 in)
2001
78.8 mm (3.1 in)
2002
102.6 mm (4.0 in)
2003
149.7 mm (5.9 in)
2004
129.4 mm (5.1 in)
2005
123.3 mm (4.9 in)
2006
150.6 mm (5.9 in)
2007
71.4 mm (2.8 in)
2008
106.0 mm (4.2 in)
2009
91.4 mm (3.6 in)
2010
138.9 mm (5.5 in)
2011
125.1 mm (4.9 in)
2012
35.5 mm (1.4 in)
Longest dry spell (CDD)
The longest dry spell of the year at Catoctin Mtn Park, 1968 to 2012. The record is 27 days in 1978, marked on the chart; the median year is 17 days.
Longest dry spell (CDD) at Catoctin Mtn Park by year
Year
Longest dry spell (CDD)
1968
25 days
1969
16 days
1970
16 days
1971
13 days
1972
12 days
1973
22 days
1974
19 days
1975
12 days
1976
21 days
1977
12 days
1978
27 days
1979
15 days
1980
11 days
1981
16 days
1982
11 days
1983
15 days
1984
14 days
1985
23 days
1986
19 days
1987
23 days
1988
21 days
1989
16 days
1990
20 days
1991
19 days
1992
20 days
1993
12 days
1994
16 days
1995
16 days
1996
15 days
1997
12 days
1998
19 days
1999
23 days
2000
21 days
2001
17 days
2002
18 days
2003
11 days
2004
16 days
2005
25 days
2006
19 days
2007
18 days
2008
23 days
2009
26 days
2010
25 days
2011
13 days
2012
8 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
35 years with a frost
Across 35 years with a frost, the median last spring frost at Catoctin Mtn Park falls on 23 April and the median first autumn frost on 25 October, which leaves a median of 187 days between them.
Fitted over all years, the growing season changes by +1.9 days per decade at this station.
Frost dates and growing season at Catoctin Mtn Park
Measure
Median, all years
Earliest period
Recent period (1973 to 2005)
Recent against earliest
Fitted trend
Last spring frost
23 April
n/a
22 April
n/a
-1.6 days per decade
First autumn frost
25 October
n/a
26 October
n/a
+0.3 days per decade
Growing days
187 days
n/a
188 days
n/a
+1.9 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
41 years, 1968 to 2009
A day with at least 75.1 mm (3.0 in) of rain is expected about once in 2 years. A day with at least 189.3 mm (7.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Catoctin Mtn Park: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
75.1 mm (3.0 in)
5 years
99.8 mm (3.9 in)
10 years
118.3 mm (4.7 in)
25 years
144.4 mm (5.7 in)
50 years
165.9 mm (6.5 in)
Longer than the 41 years of record
100 years
189.3 mm (7.5 in)
Longer than the 41 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, 41 years of values from 1968 to 2009.
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: 160.0 mm (6.3 in) in 1979; 154.4 mm (6.1 in) in 1972; 133.9 mm (5.3 in) in 1984.
Download the Data
Data for Catoctin Mtn Park standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Catoctin Mtn Park 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 2026-10-12 (12 October 2026). Records are computed by this site and are not official.