Record envelope, standing records and threshold days for Rockville 1 NE (USC00187705), Maryland, United States, with 101 years of record.
Key Facts for Rockville 1 NE
Rockville 1 NE (USC00187705) is a weather station in Maryland, United States at 39.10 latitude and -77.15 longitude, 134 m (440 ft) above sea level.
The station reports from 1907 to 2007, 101 years of record.
1,464 records set at Rockville 1 NE still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Rockville 1 NE set a daily record high maximum temperature of 37.2 C (99.0 F) on 9 July 2007.
About the Station
Location: Maryland, United States, 39.10 latitude, -77.15 longitude.
Elevation: 134 m (440 ft).
Period of record: 1907 to 2007, 101 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 Rockville 1 NE. 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 Rockville 1 NE, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.6 C (78.1 F)
-25.0 C (-13.0 F)
n/a
n/a
Feb
27.8 C (82.0 F)
-24.4 C (-11.9 F)
n/a
n/a
Mar
31.7 C (89.1 F)
-17.2 C (1.0 F)
n/a
n/a
Apr
37.8 C (100.0 F)
-7.8 C (18.0 F)
n/a
n/a
May
36.1 C (97.0 F)
-2.2 C (28.0 F)
n/a
n/a
Jun
38.9 C (102.0 F)
1.7 C (35.1 F)
n/a
n/a
Jul
40.6 C (105.1 F)
3.3 C (37.9 F)
n/a
n/a
Aug
40.0 C (104.0 F)
3.9 C (39.0 F)
n/a
n/a
Sep
37.2 C (99.0 F)
-2.2 C (28.0 F)
n/a
n/a
Oct
33.9 C (93.0 F)
-6.7 C (19.9 F)
n/a
n/a
Nov
29.4 C (84.9 F)
-12.2 C (10.0 F)
n/a
n/a
Dec
26.7 C (80.1 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 Rockville 1 NE still stand. 1914 holds the most, with 52.
Standing records at Rockville 1 NE by the year they were set
Year set
Standing records
1907
1
1908
14
1909
11
1910
12
1911
4
1912
20
1913
17
1914
52
1915
23
1916
28
1917
49
1918
48
1919
29
1920
29
1948
3
1949
14
1950
19
1951
15
1952
13
1953
17
1954
31
1955
11
1956
10
1957
21
1958
10
1959
25
1960
18
1961
13
1962
13
1963
18
1964
17
1965
14
1966
21
1967
21
1968
17
1969
9
1970
11
1971
20
1972
21
1973
7
1974
25
1975
13
1976
27
1977
23
1978
15
1979
45
1980
23
1981
17
1982
19
1983
2
1984
39
1985
23
1986
30
1987
43
1988
17
1989
33
1990
30
1991
27
1992
17
1993
15
1994
14
1995
14
1996
20
1997
12
1998
23
1999
15
2000
21
2001
16
2002
32
2003
17
2004
7
2005
15
2006
16
2007
13
All-Time Record Progression
8 new records
8 all-time records were set at Rockville 1 NE between 22 June 1972 and 12 January 1996. Each dot is a new record.
When Rockville 1 NE set new all-time records
Date
Kind
Detail
1972-06-22
Record daily precipitation
Record daily precipitation 200.7 mm (7.9 in)
1979-02-19
Record snow depth
Record snow depth 68.6 cm (27.0 in)
1985-01-21
Record low minimum temperature
Record low minimum temperature -25.0 C (-13.0 F)
1987-07-09
Record high minimum temperature
Record high minimum temperature 27.2 C (81.0 F)
1987-07-21
Record high minimum temperature
Record high minimum temperature 28.3 C (82.9 F)
1994-01-19
Record low maximum temperature
Record low maximum temperature -14.4 C (6.1 F)
1996-01-07
Record daily snowfall
Record daily snowfall 49.0 cm (19.3 in)
1996-01-12
Record snow depth
Record snow depth 76.2 cm (30.0 in)
Wettest Day of Each Month
Jun: 200.7 mm (7.9 in)
The wettest day on record for each calendar month at Rockville 1 NE. The most was 200.7 mm (7.9 in) on 22 June 1972.
Record daily precipitation for each month at Rockville 1 NE
Month
Record daily precipitation (mm)
Date
Jan
61.5 mm (2.4 in)
1 January 1976
Feb
48.8 mm (1.9 in)
12 February 1985
Mar
90.2 mm (3.6 in)
21 March 1918
Apr
76.5 mm (3.0 in)
12 April 1913
May
97.8 mm (3.9 in)
7 May 1912
Jun
200.7 mm (7.9 in)
22 June 1972
Jul
127.0 mm (5.0 in)
27 July 1908
Aug
114.3 mm (4.5 in)
1 August 1978
Sep
113.3 mm (4.5 in)
26 September 1975
Oct
110.7 mm (4.4 in)
23 October 1990
Nov
88.9 mm (3.5 in)
27 November 1993
Dec
57.9 mm (2.3 in)
24 December 1986
Period of Record Coverage
1907 to 2007
Complete yearUnder 90 percent of days
74 years of record at Rockville 1 NE, 1907 to 2007. 15 years have data for under 90 percent of days and are left out of rankings: 1907, 1910, 1911, 1913, 1948, 1963, 1966, 1968 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 55 complete years at Rockville 1 NE, 1908 to 2006. Blue stripes are years cooler than the station's own mean of 12.8 C (55.0 F); red stripes are warmer. The coolest year was 1917, at 10.6 C (51.0 F), and the warmest was 1998, at 14.3 C (57.7 F). The strongest colour marks a difference of 2.3 C (4.1 F).
Annual mean temperature at Rockville 1 NE as warming stripes, 1908 to 2006
Year
Annual mean temperature
Difference from the station mean
1908
12.3 C
-0.46 C
1912
12.0 C
-0.76 C
1914
12.1 C
-0.69 C
1915
12.2 C
-0.53 C
1916
12.1 C
-0.68 C
1917
10.6 C
-2.20 C
1918
11.8 C
-0.98 C
1919
12.8 C
-0.02 C
1920
11.3 C
-1.46 C
1949
14.2 C
+1.46 C
1950
12.9 C
+0.09 C
1951
13.1 C
+0.33 C
1952
13.5 C
+0.74 C
1953
14.2 C
+1.47 C
1954
13.9 C
+1.10 C
1955
13.9 C
+1.14 C
1956
13.6 C
+0.86 C
1958
12.6 C
-0.21 C
1959
14.2 C
+1.47 C
1960
12.7 C
-0.07 C
1961
13.2 C
+0.41 C
1962
12.4 C
-0.35 C
1964
13.4 C
+0.59 C
1965
13.0 C
+0.24 C
1967
12.0 C
-0.76 C
1971
12.5 C
-0.31 C
1972
12.3 C
-0.47 C
1973
13.2 C
+0.42 C
1974
12.7 C
-0.08 C
1975
12.7 C
-0.04 C
1977
12.5 C
-0.25 C
1978
11.6 C
-1.20 C
1979
11.3 C
-1.51 C
1980
12.0 C
-0.82 C
1982
12.1 C
-0.67 C
1985
12.3 C
-0.45 C
1986
13.2 C
+0.38 C
1988
12.7 C
-0.10 C
1989
12.5 C
-0.31 C
1990
13.8 C
+1.06 C
1991
14.0 C
+1.19 C
1992
12.2 C
-0.55 C
1993
12.7 C
-0.12 C
1994
12.9 C
+0.11 C
1995
12.7 C
-0.08 C
1996
11.9 C
-0.85 C
1997
12.8 C
+0.06 C
1998
14.3 C
+1.53 C
1999
13.6 C
+0.79 C
2000
12.7 C
-0.08 C
2001
13.4 C
+0.58 C
2002
13.7 C
+0.91 C
2003
12.3 C
-0.52 C
2005
12.5 C
-0.29 C
2006
14.0 C
+1.20 C
The annual mean temperature here has risen by 0.08 C (0.01 to 0.16) per decade over 1908 to 2006. In Fahrenheit: 0.15 F (0.01 to 0.29) per decade. The slope is a straight line fitted to 55 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Rockville 1 NE
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.08 C (0.01 to 0.16) per decade
0.15 F (0.01 to 0.29) per decade
1908 to 2006
55
Rise
Mean daily maximum
-0.02 C (-0.11 to 0.07) per decade
-0.03 F (-0.19 to 0.13) per decade
1908 to 2006
55
Not clearly different from zero
Mean daily minimum
0.2 C (0.1 to 0.3) per decade
0.3 F (0.1 to 0.5) per decade
1908 to 2006
55
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
1907 to 2007
Yearly extremes at Rockville 1 NE: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.6 C (105.1 F)
1954
35.3 C (95.5 F)
74
Coldest night (TNn)
-25.0 C (-13.0 F)
1985
-15.0 C (5.0 F)
74
Wettest day (Rx1day)
200.7 mm (7.9 in)
1972
59.7 mm (2.4 in)
74
Wettest five days (Rx5day)
310.4 mm (12.2 in)
2006
89.4 mm (3.5 in)
74
Longest dry spell (CDD)
34 days
2001
18 days
74
Hottest day (TXx)
The hottest day of the year at Rockville 1 NE, 1907 to 2007. The record is 40.6 C (105.1 F) in 1954, marked on the chart; the median year is 35.3 C (95.5 F).
Hottest day (TXx) at Rockville 1 NE by year
Year
Hottest day (TXx)
1907
18.3 C (64.9 F)
1908
34.4 C (93.9 F)
1909
33.3 C (91.9 F)
1910
32.8 C (91.0 F)
1911
33.9 C (93.0 F)
1912
31.7 C (89.1 F)
1913
31.7 C (89.1 F)
1914
38.9 C (102.0 F)
1915
37.8 C (100.0 F)
1916
35.6 C (96.1 F)
1917
36.1 C (97.0 F)
1918
40.0 C (104.0 F)
1919
37.2 C (99.0 F)
1920
34.4 C (93.9 F)
1948
35.6 C (96.1 F)
1949
35.0 C (95.0 F)
1950
32.8 C (91.0 F)
1951
33.9 C (93.0 F)
1952
35.6 C (96.1 F)
1953
37.2 C (99.0 F)
1954
40.6 C (105.1 F)
1955
37.8 C (100.0 F)
1956
35.6 C (96.1 F)
1957
37.8 C (100.0 F)
1958
35.0 C (95.0 F)
1959
37.8 C (100.0 F)
1960
33.3 C (91.9 F)
1961
34.4 C (93.9 F)
1962
35.6 C (96.1 F)
1963
35.0 C (95.0 F)
1964
35.6 C (96.1 F)
1965
35.0 C (95.0 F)
1966
38.3 C (100.9 F)
1967
33.9 C (93.0 F)
1968
36.1 C (97.0 F)
1969
36.7 C (98.1 F)
1970
34.4 C (93.9 F)
1971
34.4 C (93.9 F)
1972
35.0 C (95.0 F)
1973
35.0 C (95.0 F)
1974
34.4 C (93.9 F)
1975
35.6 C (96.1 F)
1976
35.0 C (95.0 F)
1977
37.8 C (100.0 F)
1978
35.0 C (95.0 F)
1979
33.3 C (91.9 F)
1980
36.7 C (98.1 F)
1981
34.4 C (93.9 F)
1982
35.6 C (96.1 F)
1983
25.6 C (78.1 F)
1984
36.1 C (97.0 F)
1985
35.0 C (95.0 F)
1986
36.7 C (98.1 F)
1987
37.8 C (100.0 F)
1988
37.2 C (99.0 F)
1989
33.9 C (93.0 F)
1990
35.0 C (95.0 F)
1991
36.1 C (97.0 F)
1992
35.0 C (95.0 F)
1993
37.2 C (99.0 F)
1994
35.0 C (95.0 F)
1995
36.1 C (97.0 F)
1996
34.4 C (93.9 F)
1997
37.8 C (100.0 F)
1998
35.0 C (95.0 F)
1999
38.3 C (100.9 F)
2000
35.6 C (96.1 F)
2001
35.0 C (95.0 F)
2002
36.7 C (98.1 F)
2003
33.9 C (93.0 F)
2004
33.3 C (91.9 F)
2005
36.7 C (98.1 F)
2006
36.7 C (98.1 F)
2007
37.2 C (99.0 F)
Coldest night (TNn)
The coldest night of the year at Rockville 1 NE, 1907 to 2007. The record is -25.0 C (-13.0 F) in 1985, marked on the chart; the median year is -15.0 C (5.0 F).
Coldest night (TNn) at Rockville 1 NE by year
Year
Coldest night (TNn)
1907
-6.7 C (19.9 F)
1908
-16.7 C (1.9 F)
1909
-15.6 C (3.9 F)
1910
-15.0 C (5.0 F)
1911
-6.7 C (19.9 F)
1912
-23.3 C (-9.9 F)
1913
-11.7 C (10.9 F)
1914
-24.4 C (-11.9 F)
1915
-12.8 C (9.0 F)
1916
-22.2 C (-8.0 F)
1917
-23.9 C (-11.0 F)
1918
-24.4 C (-11.9 F)
1919
-19.4 C (-2.9 F)
1920
-15.6 C (3.9 F)
1948
-13.3 C (8.1 F)
1949
-8.3 C (17.1 F)
1950
-11.7 C (10.9 F)
1951
-13.9 C (7.0 F)
1952
-11.1 C (12.0 F)
1953
-11.7 C (10.9 F)
1954
-12.8 C (9.0 F)
1955
-14.4 C (6.1 F)
1956
-9.4 C (15.1 F)
1957
-16.1 C (3.0 F)
1958
-17.2 C (1.0 F)
1959
-15.0 C (5.0 F)
1960
-15.6 C (3.9 F)
1961
-17.8 C (0.0 F)
1962
-15.6 C (3.9 F)
1963
-17.8 C (0.0 F)
1964
-12.8 C (9.0 F)
1965
-15.0 C (5.0 F)
1966
-14.4 C (6.1 F)
1967
-19.4 C (-2.9 F)
1968
-16.1 C (3.0 F)
1969
-13.3 C (8.1 F)
1970
-12.2 C (10.0 F)
1971
-17.8 C (0.0 F)
1972
-18.3 C (-0.9 F)
1973
-15.0 C (5.0 F)
1974
-16.1 C (3.0 F)
1975
-14.4 C (6.1 F)
1976
-18.3 C (-0.9 F)
1977
-20.0 C (-4.0 F)
1978
-16.7 C (1.9 F)
1979
-24.4 C (-11.9 F)
1980
-18.3 C (-0.9 F)
1981
-21.1 C (-6.0 F)
1982
-23.3 C (-9.9 F)
1983
-16.7 C (1.9 F)
1984
-10.6 C (12.9 F)
1985
-25.0 C (-13.0 F)
1986
-13.3 C (8.1 F)
1987
-20.0 C (-4.0 F)
1988
-17.2 C (1.0 F)
1989
-16.1 C (3.0 F)
1990
-11.1 C (12.0 F)
1991
-11.1 C (12.0 F)
1992
-11.7 C (10.9 F)
1993
-14.4 C (6.1 F)
1994
-21.7 C (-7.1 F)
1995
-15.6 C (3.9 F)
1996
-17.2 C (1.0 F)
1997
-13.9 C (7.0 F)
1998
-11.7 C (10.9 F)
1999
-13.9 C (7.0 F)
2000
-12.2 C (10.0 F)
2001
-11.7 C (10.9 F)
2002
-13.3 C (8.1 F)
2003
-15.0 C (5.0 F)
2004
-16.1 C (3.0 F)
2005
-13.9 C (7.0 F)
2006
-10.0 C (14.0 F)
2007
-14.4 C (6.1 F)
Wettest day (Rx1day)
The wettest day of the year at Rockville 1 NE, 1907 to 2007. The record is 200.7 mm (7.9 in) in 1972, marked on the chart; the median year is 59.7 mm (2.4 in).
Wettest day (Rx1day) at Rockville 1 NE by year
Year
Wettest day (Rx1day)
1907
27.9 mm (1.1 in)
1908
127.0 mm (5.0 in)
1909
53.3 mm (2.1 in)
1910
55.9 mm (2.2 in)
1911
36.1 mm (1.4 in)
1912
97.8 mm (3.9 in)
1913
76.5 mm (3.0 in)
1914
78.7 mm (3.1 in)
1915
80.0 mm (3.1 in)
1916
39.4 mm (1.6 in)
1917
43.7 mm (1.7 in)
1918
90.2 mm (3.6 in)
1919
43.2 mm (1.7 in)
1920
58.4 mm (2.3 in)
1948
51.6 mm (2.0 in)
1949
59.7 mm (2.4 in)
1950
52.3 mm (2.1 in)
1951
65.5 mm (2.6 in)
1952
102.9 mm (4.1 in)
1953
69.9 mm (2.8 in)
1954
34.3 mm (1.4 in)
1955
94.0 mm (3.7 in)
1956
50.8 mm (2.0 in)
1957
71.6 mm (2.8 in)
1958
109.7 mm (4.3 in)
1959
50.8 mm (2.0 in)
1960
66.5 mm (2.6 in)
1961
49.5 mm (1.9 in)
1962
50.0 mm (2.0 in)
1963
63.5 mm (2.5 in)
1964
45.7 mm (1.8 in)
1965
35.3 mm (1.4 in)
1966
40.6 mm (1.6 in)
1967
52.1 mm (2.1 in)
1968
50.8 mm (2.0 in)
1969
37.8 mm (1.5 in)
1970
73.2 mm (2.9 in)
1971
68.8 mm (2.7 in)
1972
200.7 mm (7.9 in)
1973
81.5 mm (3.2 in)
1974
66.0 mm (2.6 in)
1975
113.3 mm (4.5 in)
1976
61.5 mm (2.4 in)
1977
52.1 mm (2.1 in)
1978
114.3 mm (4.5 in)
1979
93.2 mm (3.7 in)
1980
52.1 mm (2.1 in)
1981
40.6 mm (1.6 in)
1982
53.3 mm (2.1 in)
1983
25.4 mm (1.0 in)
1984
72.9 mm (2.9 in)
1985
63.8 mm (2.5 in)
1986
57.9 mm (2.3 in)
1987
103.4 mm (4.1 in)
1988
48.3 mm (1.9 in)
1989
80.0 mm (3.1 in)
1990
110.7 mm (4.4 in)
1991
69.9 mm (2.8 in)
1992
45.0 mm (1.8 in)
1993
88.9 mm (3.5 in)
1994
59.7 mm (2.4 in)
1995
72.4 mm (2.9 in)
1996
92.5 mm (3.6 in)
1997
64.8 mm (2.6 in)
1998
41.9 mm (1.6 in)
1999
57.2 mm (2.3 in)
2000
50.8 mm (2.0 in)
2001
66.0 mm (2.6 in)
2002
41.1 mm (1.6 in)
2003
47.5 mm (1.9 in)
2004
46.2 mm (1.8 in)
2005
103.1 mm (4.1 in)
2006
130.8 mm (5.1 in)
2007
48.3 mm (1.9 in)
Wettest five days (Rx5day)
The wettest five days of the year at Rockville 1 NE, 1907 to 2007. The record is 310.4 mm (12.2 in) in 2006, marked on the chart; the median year is 89.4 mm (3.5 in).
Wettest five days (Rx5day) at Rockville 1 NE by year
Year
Wettest five days (Rx5day)
1907
27.9 mm (1.1 in)
1908
157.2 mm (6.2 in)
1909
76.6 mm (3.0 in)
1910
79.9 mm (3.1 in)
1911
91.7 mm (3.6 in)
1912
121.4 mm (4.8 in)
1913
108.7 mm (4.3 in)
1914
130.1 mm (5.1 in)
1915
113.1 mm (4.5 in)
1916
114.8 mm (4.5 in)
1917
89.6 mm (3.5 in)
1918
96.3 mm (3.8 in)
1919
124.6 mm (4.9 in)
1920
82.8 mm (3.3 in)
1948
72.6 mm (2.9 in)
1949
78.5 mm (3.1 in)
1950
86.1 mm (3.4 in)
1951
143.2 mm (5.6 in)
1952
148.3 mm (5.8 in)
1953
90.7 mm (3.6 in)
1954
47.5 mm (1.9 in)
1955
119.1 mm (4.7 in)
1956
78.0 mm (3.1 in)
1957
86.8 mm (3.4 in)
1958
131.8 mm (5.2 in)
1959
64.5 mm (2.5 in)
1960
94.9 mm (3.7 in)
1961
80.2 mm (3.2 in)
1962
65.8 mm (2.6 in)
1963
84.3 mm (3.3 in)
1964
70.2 mm (2.8 in)
1965
51.6 mm (2.0 in)
1966
53.3 mm (2.1 in)
1967
87.7 mm (3.5 in)
1968
80.6 mm (3.2 in)
1969
44.9 mm (1.8 in)
1970
76.2 mm (3.0 in)
1971
122.2 mm (4.8 in)
1972
274.0 mm (10.8 in)
1973
96.0 mm (3.8 in)
1974
109.9 mm (4.3 in)
1975
228.6 mm (9.0 in)
1976
94.0 mm (3.7 in)
1977
74.2 mm (2.9 in)
1978
125.5 mm (4.9 in)
1979
174.7 mm (6.9 in)
1980
91.0 mm (3.6 in)
1981
61.7 mm (2.4 in)
1982
68.6 mm (2.7 in)
1983
48.3 mm (1.9 in)
1984
89.2 mm (3.5 in)
1985
76.0 mm (3.0 in)
1986
74.2 mm (2.9 in)
1987
136.9 mm (5.4 in)
1988
89.7 mm (3.5 in)
1989
112.8 mm (4.4 in)
1990
114.0 mm (4.5 in)
1991
75.7 mm (3.0 in)
1992
76.5 mm (3.0 in)
1993
129.5 mm (5.1 in)
1994
96.0 mm (3.8 in)
1995
100.1 mm (3.9 in)
1996
118.4 mm (4.7 in)
1997
78.6 mm (3.1 in)
1998
83.8 mm (3.3 in)
1999
109.2 mm (4.3 in)
2000
66.6 mm (2.6 in)
2001
85.0 mm (3.3 in)
2002
65.5 mm (2.6 in)
2003
95.8 mm (3.8 in)
2004
49.7 mm (2.0 in)
2005
155.9 mm (6.1 in)
2006
310.4 mm (12.2 in)
2007
79.8 mm (3.1 in)
Longest dry spell (CDD)
The longest dry spell of the year at Rockville 1 NE, 1907 to 2007. The record is 34 days in 2001, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Rockville 1 NE by year
Year
Longest dry spell (CDD)
1907
6 days
1908
21 days
1909
24 days
1910
23 days
1911
16 days
1912
21 days
1913
17 days
1914
27 days
1915
18 days
1916
17 days
1917
22 days
1918
20 days
1919
14 days
1920
26 days
1948
16 days
1949
18 days
1950
16 days
1951
22 days
1952
16 days
1953
31 days
1954
17 days
1955
22 days
1956
16 days
1957
18 days
1958
23 days
1959
17 days
1960
12 days
1961
17 days
1962
16 days
1963
32 days
1964
26 days
1965
16 days
1966
17 days
1967
22 days
1968
25 days
1969
19 days
1970
17 days
1971
15 days
1972
12 days
1973
15 days
1974
19 days
1975
13 days
1976
16 days
1977
29 days
1978
18 days
1979
16 days
1980
14 days
1981
20 days
1982
23 days
1983
13 days
1984
23 days
1985
13 days
1986
22 days
1987
13 days
1988
29 days
1989
23 days
1990
21 days
1991
23 days
1992
18 days
1993
20 days
1994
16 days
1995
33 days
1996
17 days
1997
20 days
1998
33 days
1999
19 days
2000
21 days
2001
34 days
2002
18 days
2003
14 days
2004
17 days
2005
20 days
2006
31 days
2007
14 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
55 years with a frost
Across 55 years with a frost, the median last spring frost at Rockville 1 NE falls on 15 April and the median first autumn frost on 27 October, which leaves a median of 198 days between them.
Fitted over all years, the growing season changes by +3.1 days per decade at this station.
Frost dates and growing season at Rockville 1 NE
Measure
Median, all years
Earliest period
Recent period (1971 to 2006)
Recent against earliest
Fitted trend
Last spring frost
15 April
n/a
10 April
n/a
-2.0 days per decade
First autumn frost
27 October
n/a
26 October
n/a
+1.0 days per decade
Growing days
198 days
n/a
200 days
n/a
+3.1 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
60 years, 1908 to 2006
A day with at least 63.9 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 183.7 mm (7.2 in) of rain is expected about once in 100 years.
Rainfall return levels at Rockville 1 NE: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
63.9 mm (2.5 in)
5 years
88.7 mm (3.5 in)
10 years
107.7 mm (4.2 in)
25 years
135.1 mm (5.3 in)
50 years
158.2 mm (6.2 in)
100 years
183.7 mm (7.2 in)
Longer than the 60 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, 60 years of values from 1908 to 2006.
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: 200.7 mm (7.9 in) in 1972; 130.8 mm (5.1 in) in 2006; 127.0 mm (5.0 in) in 1908.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Rockville 1 NE standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Rockville 1 NE 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.