Record envelope, standing records and threshold days for Tonoloway (USC00188855), Maryland, United States, with 34 years of record.
Key Facts for Tonoloway
Tonoloway (USC00188855) is a weather station in Maryland, United States at 39.67 latitude and -78.25 longitude, 168 m (551 ft) above sea level.
The station reports from 1924 to 1957, 34 years of record.
1,464 records set at Tonoloway still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Tonoloway set a monthly record high minimum temperature of 20.0 C (68.0 F) on 28 April 1957.
About the Station
Location: Maryland, United States, 39.67 latitude, -78.25 longitude.
Elevation: 168 m (551 ft).
Period of record: 1924 to 1957, 34 years.
Eligible elements: tmax, tmin, prcp.
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 Tonoloway. 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 Tonoloway, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
26.1 C (79.0 F)
-26.1 C (-15.0 F)
n/a
n/a
Feb
26.7 C (80.1 F)
-27.2 C (-17.0 F)
n/a
n/a
Mar
30.0 C (86.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Apr
35.0 C (95.0 F)
-7.2 C (19.0 F)
n/a
n/a
May
35.6 C (96.1 F)
-5.6 C (21.9 F)
n/a
n/a
Jun
38.3 C (100.9 F)
-1.1 C (30.0 F)
n/a
n/a
Jul
41.7 C (107.1 F)
3.9 C (39.0 F)
n/a
n/a
Aug
40.6 C (105.1 F)
2.2 C (36.0 F)
n/a
n/a
Sep
38.9 C (102.0 F)
-3.9 C (25.0 F)
n/a
n/a
Oct
36.7 C (98.1 F)
-8.9 C (16.0 F)
n/a
n/a
Nov
30.0 C (86.0 F)
-19.4 C (-2.9 F)
n/a
n/a
Dec
22.8 C (73.0 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 Tonoloway still stand. 1930 holds the most, with 86.
Standing records at Tonoloway by the year they were set
Year set
Standing records
1924
35
1925
68
1926
60
1927
68
1928
46
1929
51
1930
86
1931
54
1932
58
1933
62
1934
70
1935
51
1936
59
1937
42
1938
32
1939
38
1940
46
1941
36
1942
42
1943
42
1944
26
1945
39
1946
27
1947
39
1948
28
1949
38
1950
38
1951
34
1952
19
1953
31
1954
23
1955
30
1956
37
1957
9
Wettest Day of Each Month
Oct: 115.6 mm (4.6 in)
The wettest day on record for each calendar month at Tonoloway. The most was 115.6 mm (4.6 in) on 15 October 1942.
Record daily precipitation for each month at Tonoloway
Month
Record daily precipitation (mm)
Date
Jan
48.0 mm (1.9 in)
1 January 1948
Feb
44.5 mm (1.8 in)
14 February 1936
Mar
104.9 mm (4.1 in)
17 March 1936
Apr
95.8 mm (3.8 in)
26 April 1937
May
51.6 mm (2.0 in)
12 May 1932
Jun
80.8 mm (3.2 in)
8 June 1940
Jul
66.0 mm (2.6 in)
18 July 1945
Aug
70.6 mm (2.8 in)
23 August 1933
Sep
68.6 mm (2.7 in)
18 September 1945
Oct
115.6 mm (4.6 in)
15 October 1942
Nov
71.1 mm (2.8 in)
21 November 1952
Dec
51.1 mm (2.0 in)
4 December 1950
Period of Record Coverage
1924 to 1957
Complete yearUnder 90 percent of days
34 years of record at Tonoloway, 1924 to 1957. 3 years have data for under 90 percent of days and are left out of rankings: 1924, 1954, 1957.
Cooler than the station meanWarmer than the station mean
One stripe for each of 26 complete years at Tonoloway, 1926 to 1956. Blue stripes are years cooler than the station's own mean of 11.5 C (52.7 F); red stripes are warmer. The coolest year was 1940, at 10.2 C (50.3 F), and the warmest was 1953, at 12.8 C (55.1 F). The strongest colour marks a difference of 1.4 C (2.5 F).
Annual mean temperature at Tonoloway as warming stripes, 1926 to 1956
Year
Annual mean temperature
Difference from the station mean
1926
10.7 C
-0.75 C
1927
11.7 C
+0.25 C
1928
11.4 C
-0.04 C
1929
11.4 C
-0.13 C
1930
11.6 C
+0.15 C
1931
12.7 C
+1.26 C
1932
12.0 C
+0.53 C
1933
11.8 C
+0.34 C
1934
11.5 C
-0.02 C
1935
11.1 C
-0.39 C
1936
10.9 C
-0.62 C
1937
11.2 C
-0.25 C
1938
12.0 C
+0.56 C
1939
12.0 C
+0.56 C
1940
10.2 C
-1.30 C
1941
11.4 C
-0.10 C
1942
11.4 C
-0.11 C
1943
11.0 C
-0.45 C
1944
11.2 C
-0.33 C
1945
11.2 C
-0.31 C
1946
11.7 C
+0.17 C
1947
11.0 C
-0.46 C
1950
11.3 C
-0.19 C
1951
11.8 C
+0.28 C
1953
12.8 C
+1.35 C
1956
11.6 C
+0.12 C
This station does not have enough complete years (30 are needed) to fit a temperature trend.
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
1924 to 1957
Yearly extremes at Tonoloway: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.7 C (107.1 F)
1934
37.2 C (99.0 F)
34
Coldest night (TNn)
-27.2 C (-17.0 F)
1934
-18.3 C (-0.9 F)
34
Wettest day (Rx1day)
115.6 mm (4.6 in)
1942
50.8 mm (2.0 in)
34
Wettest five days (Rx5day)
179.1 mm (7.1 in)
1942
92.2 mm (3.6 in)
34
Longest dry spell (CDD)
48 days
1930
19 days
34
Hottest day (TXx)
The hottest day of the year at Tonoloway, 1924 to 1957. The record is 41.7 C (107.1 F) in 1934, marked on the chart; the median year is 37.2 C (99.0 F).
Hottest day (TXx) at Tonoloway by year
Year
Hottest day (TXx)
1924
38.3 C (100.9 F)
1925
37.8 C (100.0 F)
1926
41.1 C (106.0 F)
1927
36.1 C (97.0 F)
1928
36.1 C (97.0 F)
1929
37.2 C (99.0 F)
1930
40.6 C (105.1 F)
1931
37.8 C (100.0 F)
1932
38.9 C (102.0 F)
1933
38.3 C (100.9 F)
1934
41.7 C (107.1 F)
1935
36.7 C (98.1 F)
1936
41.1 C (106.0 F)
1937
37.2 C (99.0 F)
1938
36.7 C (98.1 F)
1939
36.7 C (98.1 F)
1940
36.7 C (98.1 F)
1941
36.7 C (98.1 F)
1942
36.1 C (97.0 F)
1943
38.3 C (100.9 F)
1944
38.9 C (102.0 F)
1945
36.1 C (97.0 F)
1946
35.6 C (96.1 F)
1947
35.0 C (95.0 F)
1948
39.4 C (102.9 F)
1949
36.1 C (97.0 F)
1950
33.9 C (93.0 F)
1951
36.7 C (98.1 F)
1952
37.8 C (100.0 F)
1953
38.9 C (102.0 F)
1954
39.4 C (102.9 F)
1955
37.2 C (99.0 F)
1956
35.0 C (95.0 F)
1957
32.8 C (91.0 F)
Coldest night (TNn)
The coldest night of the year at Tonoloway, 1924 to 1957. The record is -27.2 C (-17.0 F) in 1934, marked on the chart; the median year is -18.3 C (-0.9 F).
Coldest night (TNn) at Tonoloway by year
Year
Coldest night (TNn)
1924
-17.2 C (1.0 F)
1925
-16.1 C (3.0 F)
1926
-19.4 C (-2.9 F)
1927
-16.7 C (1.9 F)
1928
-16.1 C (3.0 F)
1929
-17.2 C (1.0 F)
1930
-22.8 C (-9.0 F)
1931
-14.4 C (6.1 F)
1932
-18.3 C (-0.9 F)
1933
-19.4 C (-2.9 F)
1934
-27.2 C (-17.0 F)
1935
-26.1 C (-15.0 F)
1936
-25.6 C (-14.1 F)
1937
-15.6 C (3.9 F)
1938
-18.3 C (-0.9 F)
1939
-16.1 C (3.0 F)
1940
-20.0 C (-4.0 F)
1941
-13.9 C (7.0 F)
1942
-24.4 C (-11.9 F)
1943
-20.0 C (-4.0 F)
1944
-15.6 C (3.9 F)
1945
-18.9 C (-2.0 F)
1946
-22.8 C (-9.0 F)
1947
-16.7 C (1.9 F)
1948
-18.3 C (-0.9 F)
1949
-19.4 C (-2.9 F)
1950
-17.8 C (0.0 F)
1951
-19.4 C (-2.9 F)
1952
-12.8 C (9.0 F)
1953
-12.8 C (9.0 F)
1954
-16.7 C (1.9 F)
1955
-18.9 C (-2.0 F)
1956
-15.0 C (5.0 F)
1957
-18.9 C (-2.0 F)
Wettest day (Rx1day)
The wettest day of the year at Tonoloway, 1924 to 1957. The record is 115.6 mm (4.6 in) in 1942, marked on the chart; the median year is 50.8 mm (2.0 in).
Wettest day (Rx1day) at Tonoloway by year
Year
Wettest day (Rx1day)
1924
50.8 mm (2.0 in)
1925
34.5 mm (1.4 in)
1926
50.8 mm (2.0 in)
1927
65.8 mm (2.6 in)
1928
50.8 mm (2.0 in)
1929
96.0 mm (3.8 in)
1930
37.1 mm (1.5 in)
1931
35.3 mm (1.4 in)
1932
51.6 mm (2.0 in)
1933
70.6 mm (2.8 in)
1934
45.2 mm (1.8 in)
1935
45.2 mm (1.8 in)
1936
104.9 mm (4.1 in)
1937
95.8 mm (3.8 in)
1938
50.8 mm (2.0 in)
1939
52.1 mm (2.1 in)
1940
80.8 mm (3.2 in)
1941
63.0 mm (2.5 in)
1942
115.6 mm (4.6 in)
1943
41.7 mm (1.6 in)
1944
34.3 mm (1.4 in)
1945
68.6 mm (2.7 in)
1946
48.8 mm (1.9 in)
1947
30.5 mm (1.2 in)
1948
61.0 mm (2.4 in)
1949
64.5 mm (2.5 in)
1950
51.1 mm (2.0 in)
1951
48.3 mm (1.9 in)
1952
71.1 mm (2.8 in)
1953
45.7 mm (1.8 in)
1954
51.8 mm (2.0 in)
1955
46.5 mm (1.8 in)
1956
48.3 mm (1.9 in)
1957
27.9 mm (1.1 in)
Wettest five days (Rx5day)
The wettest five days of the year at Tonoloway, 1924 to 1957. The record is 179.1 mm (7.1 in) in 1942, marked on the chart; the median year is 92.2 mm (3.6 in).
Wettest five days (Rx5day) at Tonoloway by year
Year
Wettest five days (Rx5day)
1924
130.3 mm (5.1 in)
1925
66.0 mm (2.6 in)
1926
91.8 mm (3.6 in)
1927
110.2 mm (4.3 in)
1928
82.0 mm (3.2 in)
1929
135.9 mm (5.4 in)
1930
50.8 mm (2.0 in)
1931
64.8 mm (2.6 in)
1932
116.4 mm (4.6 in)
1933
92.5 mm (3.6 in)
1934
87.6 mm (3.4 in)
1935
89.7 mm (3.5 in)
1936
153.2 mm (6.0 in)
1937
149.7 mm (5.9 in)
1938
57.2 mm (2.3 in)
1939
136.7 mm (5.4 in)
1940
99.1 mm (3.9 in)
1941
94.2 mm (3.7 in)
1942
179.1 mm (7.1 in)
1943
73.5 mm (2.9 in)
1944
55.9 mm (2.2 in)
1945
134.9 mm (5.3 in)
1946
73.6 mm (2.9 in)
1947
73.4 mm (2.9 in)
1948
91.7 mm (3.6 in)
1949
99.8 mm (3.9 in)
1950
89.8 mm (3.5 in)
1951
72.1 mm (2.8 in)
1952
167.1 mm (6.6 in)
1953
73.7 mm (2.9 in)
1954
102.8 mm (4.0 in)
1955
109.0 mm (4.3 in)
1956
116.2 mm (4.6 in)
1957
50.3 mm (2.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Tonoloway, 1924 to 1957. The record is 48 days in 1930, marked on the chart; the median year is 19 days.
Longest dry spell (CDD) at Tonoloway by year
Year
Longest dry spell (CDD)
1924
19 days
1925
13 days
1926
19 days
1927
13 days
1928
14 days
1929
14 days
1930
48 days
1931
19 days
1932
22 days
1933
19 days
1934
18 days
1935
15 days
1936
18 days
1937
16 days
1938
22 days
1939
21 days
1940
12 days
1941
22 days
1942
14 days
1943
23 days
1944
25 days
1945
16 days
1946
15 days
1947
23 days
1948
12 days
1949
14 days
1950
16 days
1951
21 days
1952
29 days
1953
36 days
1954
19 days
1955
25 days
1956
36 days
1957
15 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
26 years with a frost
Across 26 years with a frost, the median last spring frost at Tonoloway falls on 9 May and the median first autumn frost on 30 September, which leaves a median of 150 days between them.
Fitted over all years, the growing season changes by +1.1 days per decade at this station.
Frost dates and growing season at Tonoloway
Measure
Median, all years
Earliest period
Recent period (1926 to 1956)
Recent against earliest
Fitted trend
Last spring frost
9 May
n/a
9 May
n/a
-3.2 days per decade
First autumn frost
30 September
n/a
30 September
n/a
-2.0 days per decade
Growing days
150 days
n/a
150 days
n/a
+1.1 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.
Download the Data
Data for Tonoloway standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Tonoloway 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.