Record envelope, standing records and threshold days for Boonville (USC00230817), Missouri, United States, with 72 years of record.
Key Facts for Boonville
Boonville (USC00230817) is a weather station in Missouri, United States at 38.97 latitude and -92.76 longitude, 227 m (744 ft) above sea level.
The station reports from 1937 to 2008, 72 years of record.
1,464 records set at Boonville still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Boonville set a daily record precipitation of 24.6 mm (1.0 in) on 29 August 2008.
About the Station
Location: Missouri, United States, 38.97 latitude, -92.76 longitude.
Elevation: 227 m (744 ft).
Period of record: 1937 to 2008, 72 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 Boonville. 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 Boonville, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.0 C (77.0 F)
-27.8 C (-18.0 F)
n/a
n/a
Feb
25.6 C (78.1 F)
-24.4 C (-11.9 F)
n/a
n/a
Mar
30.0 C (86.0 F)
-22.8 C (-9.0 F)
n/a
n/a
Apr
33.3 C (91.9 F)
-7.2 C (19.0 F)
n/a
n/a
May
35.0 C (95.0 F)
0.6 C (33.1 F)
n/a
n/a
Jun
39.4 C (102.9 F)
6.1 C (43.0 F)
n/a
n/a
Jul
43.3 C (109.9 F)
10.0 C (50.0 F)
n/a
n/a
Aug
42.2 C (108.0 F)
7.2 C (45.0 F)
n/a
n/a
Sep
40.0 C (104.0 F)
-2.2 C (28.0 F)
n/a
n/a
Oct
36.1 C (97.0 F)
-5.6 C (21.9 F)
n/a
n/a
Nov
30.6 C (87.1 F)
-17.8 C (0.0 F)
n/a
n/a
Dec
23.3 C (73.9 F)
-30.0 C (-22.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Boonville still stand. 1980 holds the most, with 46.
Standing records at Boonville by the year they were set
Year set
Standing records
1937
11
1938
35
1939
31
1940
23
1941
16
1942
26
1943
30
1944
17
1945
21
1946
20
1947
17
1948
23
1949
25
1950
43
1951
25
1952
33
1953
25
1954
27
1955
18
1956
24
1957
9
1958
18
1959
21
1960
24
1961
12
1962
22
1963
30
1964
14
1965
25
1966
26
1967
23
1968
17
1969
6
1970
16
1971
21
1972
31
1973
9
1974
28
1975
10
1976
20
1977
5
1978
16
1979
18
1980
46
1981
14
1982
16
1983
26
1984
15
1985
19
1986
20
1987
13
1988
19
1989
30
1990
20
1991
28
1992
15
1993
12
1994
10
1995
13
1996
22
1997
17
1998
28
1999
27
2000
36
2001
18
2002
16
2003
16
2004
8
2005
9
2006
19
2007
15
2008
6
All-Time Record Progression
8 new records
8 all-time records were set at Boonville between 24 February 1975 and 22 December 1989. Each dot is a new record.
When Boonville set new all-time records
Date
Kind
Detail
1975-02-24
Record daily snowfall
Record daily snowfall 33.0 cm (13.0 in)
1980-07-08
Record high minimum temperature
Record high minimum temperature 27.2 C (81.0 F)
1980-07-09
Record high minimum temperature
Record high minimum temperature 28.3 C (82.9 F)
1980-07-10
Record high minimum temperature
Record high minimum temperature 28.9 C (84.0 F)
1980-07-16
Record high minimum temperature
Record high minimum temperature 29.4 C (84.9 F)
1982-01-10
Record low minimum temperature
Record low minimum temperature -27.8 C (-18.0 F)
1983-12-25
Record low maximum temperature
Record low maximum temperature -23.3 C (-9.9 F)
1989-12-22
Record low minimum temperature
Record low minimum temperature -30.0 C (-22.0 F)
Wettest Day of Each Month
Jul: 177.8 mm (7.0 in)
The wettest day on record for each calendar month at Boonville. The most was 177.8 mm (7.0 in) on 5 July 1942.
Record daily precipitation for each month at Boonville
Month
Record daily precipitation (mm)
Date
Jan
64.5 mm (2.5 in)
1 January 1985
Feb
87.9 mm (3.5 in)
21 February 1997
Mar
62.7 mm (2.5 in)
15 March 1944
Apr
104.1 mm (4.1 in)
2 April 1983
May
124.0 mm (4.9 in)
16 May 1990
Jun
152.4 mm (6.0 in)
7 June 1993
Jul
177.8 mm (7.0 in)
5 July 1942
Aug
139.7 mm (5.5 in)
27 August 1982
Sep
121.9 mm (4.8 in)
1 September 2003
Oct
115.3 mm (4.5 in)
3 October 1986
Nov
107.7 mm (4.2 in)
19 November 1985
Dec
99.1 mm (3.9 in)
2 December 1982
Period of Record Coverage
1937 to 2008
Complete yearUnder 90 percent of days
72 years of record at Boonville, 1937 to 2008. 6 years have data for under 90 percent of days and are left out of rankings: 1937, 1977, 2005, 2006, 2007, 2008.
Cooler than the station meanWarmer than the station mean
One stripe for each of 65 complete years at Boonville, 1938 to 2007. Blue stripes are years cooler than the station's own mean of 12.4 C (54.4 F); red stripes are warmer. The coolest year was 1985, at 10.9 C (51.7 F), and the warmest was 1938, at 14.8 C (58.6 F). The strongest colour marks a difference of 2.4 C (4.3 F).
Annual mean temperature at Boonville as warming stripes, 1938 to 2007
Year
Annual mean temperature
Difference from the station mean
1938
14.8 C
+2.34 C
1939
13.7 C
+1.29 C
1940
11.7 C
-0.76 C
1941
13.4 C
+0.92 C
1942
11.9 C
-0.55 C
1943
11.4 C
-1.07 C
1944
11.9 C
-0.56 C
1945
11.9 C
-0.52 C
1946
13.8 C
+1.30 C
1947
12.1 C
-0.33 C
1948
11.4 C
-1.03 C
1949
11.7 C
-0.74 C
1950
11.0 C
-1.43 C
1951
11.0 C
-1.43 C
1952
12.7 C
+0.23 C
1953
13.3 C
+0.83 C
1954
13.3 C
+0.82 C
1955
12.7 C
+0.24 C
1956
13.1 C
+0.66 C
1957
12.6 C
+0.12 C
1958
11.8 C
-0.63 C
1959
12.5 C
+0.08 C
1960
11.8 C
-0.66 C
1961
11.7 C
-0.71 C
1962
12.2 C
-0.23 C
1963
12.5 C
+0.06 C
1964
12.7 C
+0.28 C
1965
12.5 C
+0.08 C
1966
11.5 C
-0.99 C
1967
11.7 C
-0.75 C
1970
12.0 C
-0.45 C
1971
12.5 C
+0.08 C
1972
11.7 C
-0.74 C
1973
12.7 C
+0.23 C
1974
12.1 C
-0.38 C
1975
12.4 C
-0.04 C
1976
11.8 C
-0.64 C
1978
11.3 C
-1.16 C
1979
11.1 C
-1.38 C
1980
12.9 C
+0.40 C
1981
12.7 C
+0.27 C
1982
11.7 C
-0.73 C
1983
12.2 C
-0.21 C
1984
12.4 C
-0.03 C
1985
10.9 C
-1.52 C
1986
12.5 C
+0.04 C
1987
13.1 C
+0.69 C
1988
12.1 C
-0.35 C
1989
11.0 C
-1.50 C
1990
13.1 C
+0.66 C
1991
13.2 C
+0.70 C
1992
12.1 C
-0.32 C
1993
11.7 C
-0.78 C
1994
12.8 C
+0.35 C
1995
12.6 C
+0.12 C
1996
12.1 C
-0.37 C
1997
12.7 C
+0.23 C
1998
14.7 C
+2.21 C
1999
14.2 C
+1.79 C
2000
13.5 C
+1.07 C
2001
14.1 C
+1.63 C
2002
13.6 C
+1.18 C
2003
13.0 C
+0.53 C
2004
12.9 C
+0.46 C
2007
13.4 C
+0.94 C
The fitted trend in annual mean temperature here over 1938 to 2007 is 0.09 C (-0.02 to 0.20) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.16 F (-0.03 to 0.36) per decade. The slope is a straight line fitted to 65 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Boonville
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.09 C (-0.02 to 0.20) per decade
0.16 F (-0.03 to 0.36) per decade
1938 to 2007
65
Not clearly different from zero
Mean daily maximum
0.10 C (-0.02 to 0.22) per decade
0.19 F (-0.03 to 0.40) per decade
1938 to 2007
65
Not clearly different from zero
Mean daily minimum
0.08 C (-0.03 to 0.18) per decade
0.1 F (-0.1 to 0.3) per decade
1938 to 2007
65
Not clearly different from zero
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
1937 to 2008
Yearly extremes at Boonville: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
43.3 C (109.9 F)
1954
37.8 C (100.0 F)
72
Coldest night (TNn)
-30.0 C (-22.0 F)
1989
-20.8 C (-5.5 F)
72
Wettest day (Rx1day)
177.8 mm (7.0 in)
1942
68.4 mm (2.7 in)
72
Wettest five days (Rx5day)
242.3 mm (9.5 in)
1985
108.2 mm (4.3 in)
72
Longest dry spell (CDD)
45 days
1964
23 days
72
Hottest day (TXx)
The hottest day of the year at Boonville, 1937 to 2008. The record is 43.3 C (109.9 F) in 1954, marked on the chart; the median year is 37.8 C (100.0 F).
Hottest day (TXx) at Boonville by year
Year
Hottest day (TXx)
1937
30.6 C (87.1 F)
1938
37.8 C (100.0 F)
1939
38.9 C (102.0 F)
1940
38.9 C (102.0 F)
1941
38.9 C (102.0 F)
1942
35.6 C (96.1 F)
1943
36.7 C (98.1 F)
1944
37.2 C (99.0 F)
1945
36.7 C (98.1 F)
1946
38.9 C (102.0 F)
1947
39.4 C (102.9 F)
1948
36.7 C (98.1 F)
1949
35.6 C (96.1 F)
1950
33.9 C (93.0 F)
1951
36.1 C (97.0 F)
1952
40.0 C (104.0 F)
1953
38.3 C (100.9 F)
1954
43.3 C (109.9 F)
1955
39.4 C (102.9 F)
1956
38.3 C (100.9 F)
1957
39.4 C (102.9 F)
1958
36.1 C (97.0 F)
1959
37.8 C (100.0 F)
1960
38.3 C (100.9 F)
1961
34.4 C (93.9 F)
1962
41.7 C (107.1 F)
1963
37.8 C (100.0 F)
1964
39.4 C (102.9 F)
1965
34.4 C (93.9 F)
1966
37.8 C (100.0 F)
1967
35.0 C (95.0 F)
1968
35.0 C (95.0 F)
1969
36.7 C (98.1 F)
1970
38.9 C (102.0 F)
1971
36.7 C (98.1 F)
1972
37.8 C (100.0 F)
1973
37.2 C (99.0 F)
1974
38.9 C (102.0 F)
1975
37.8 C (100.0 F)
1976
38.3 C (100.9 F)
1977
36.7 C (98.1 F)
1978
36.7 C (98.1 F)
1979
36.1 C (97.0 F)
1980
43.3 C (109.9 F)
1981
36.7 C (98.1 F)
1982
37.2 C (99.0 F)
1983
40.0 C (104.0 F)
1984
41.1 C (106.0 F)
1985
36.7 C (98.1 F)
1986
36.7 C (98.1 F)
1987
40.0 C (104.0 F)
1988
39.4 C (102.9 F)
1989
35.0 C (95.0 F)
1990
37.8 C (100.0 F)
1991
38.9 C (102.0 F)
1992
33.9 C (93.0 F)
1993
35.6 C (96.1 F)
1994
36.1 C (97.0 F)
1995
37.8 C (100.0 F)
1996
37.8 C (100.0 F)
1997
38.9 C (102.0 F)
1998
40.0 C (104.0 F)
1999
41.7 C (107.1 F)
2000
40.0 C (104.0 F)
2001
40.6 C (105.1 F)
2002
38.9 C (102.0 F)
2003
42.2 C (108.0 F)
2004
36.1 C (97.0 F)
2005
40.6 C (105.1 F)
2006
41.1 C (106.0 F)
2007
40.6 C (105.1 F)
2008
36.7 C (98.1 F)
Coldest night (TNn)
The coldest night of the year at Boonville, 1937 to 2008. The record is -30.0 C (-22.0 F) in 1989, marked on the chart; the median year is -20.8 C (-5.5 F).
Coldest night (TNn) at Boonville by year
Year
Coldest night (TNn)
1937
-15.6 C (3.9 F)
1938
-17.2 C (1.0 F)
1939
-17.2 C (1.0 F)
1940
-26.1 C (-15.0 F)
1941
-14.4 C (6.1 F)
1942
-21.1 C (-6.0 F)
1943
-25.6 C (-14.1 F)
1944
-21.7 C (-7.1 F)
1945
-21.1 C (-6.0 F)
1946
-18.9 C (-2.0 F)
1947
-23.9 C (-11.0 F)
1948
-23.3 C (-9.9 F)
1949
-22.8 C (-9.0 F)
1950
-19.4 C (-2.9 F)
1951
-22.8 C (-9.0 F)
1952
-16.7 C (1.9 F)
1953
-18.9 C (-2.0 F)
1954
-17.8 C (0.0 F)
1955
-20.6 C (-5.1 F)
1956
-16.7 C (1.9 F)
1957
-18.3 C (-0.9 F)
1958
-22.2 C (-8.0 F)
1959
-23.3 C (-9.9 F)
1960
-22.8 C (-9.0 F)
1961
-20.0 C (-4.0 F)
1962
-21.7 C (-7.1 F)
1963
-23.9 C (-11.0 F)
1964
-18.3 C (-0.9 F)
1965
-21.7 C (-7.1 F)
1966
-26.1 C (-15.0 F)
1967
-20.6 C (-5.1 F)
1968
-23.9 C (-11.0 F)
1969
-21.1 C (-6.0 F)
1970
-23.9 C (-11.0 F)
1971
-19.4 C (-2.9 F)
1972
-25.0 C (-13.0 F)
1973
-19.4 C (-2.9 F)
1974
-25.6 C (-14.1 F)
1975
-19.4 C (-2.9 F)
1976
-22.8 C (-9.0 F)
1977
-13.3 C (8.1 F)
1978
-21.1 C (-6.0 F)
1979
-24.4 C (-11.9 F)
1980
-20.0 C (-4.0 F)
1981
-24.4 C (-11.9 F)
1982
-27.8 C (-18.0 F)
1983
-26.1 C (-15.0 F)
1984
-20.0 C (-4.0 F)
1985
-26.1 C (-15.0 F)
1986
-19.4 C (-2.9 F)
1987
-16.7 C (1.9 F)
1988
-22.2 C (-8.0 F)
1989
-30.0 C (-22.0 F)
1990
-18.3 C (-0.9 F)
1991
-17.8 C (0.0 F)
1992
-13.3 C (8.1 F)
1993
-21.1 C (-6.0 F)
1994
-21.1 C (-6.0 F)
1995
-17.2 C (1.0 F)
1996
-24.4 C (-11.9 F)
1997
-22.2 C (-8.0 F)
1998
-16.1 C (3.0 F)
1999
-21.1 C (-6.0 F)
2000
-19.4 C (-2.9 F)
2001
-21.1 C (-6.0 F)
2002
-16.1 C (3.0 F)
2003
-19.4 C (-2.9 F)
2004
-18.3 C (-0.9 F)
2005
-13.9 C (7.0 F)
2006
-15.0 C (5.0 F)
2007
-17.2 C (1.0 F)
2008
-17.8 C (0.0 F)
Wettest day (Rx1day)
The wettest day of the year at Boonville, 1937 to 2008. The record is 177.8 mm (7.0 in) in 1942, marked on the chart; the median year is 68.4 mm (2.7 in).
Wettest day (Rx1day) at Boonville by year
Year
Wettest day (Rx1day)
1937
27.4 mm (1.1 in)
1938
50.0 mm (2.0 in)
1939
88.1 mm (3.5 in)
1940
50.8 mm (2.0 in)
1941
66.8 mm (2.6 in)
1942
177.8 mm (7.0 in)
1943
90.2 mm (3.6 in)
1944
62.7 mm (2.5 in)
1945
68.6 mm (2.7 in)
1946
50.0 mm (2.0 in)
1947
79.2 mm (3.1 in)
1948
83.8 mm (3.3 in)
1949
81.3 mm (3.2 in)
1950
62.5 mm (2.5 in)
1951
88.1 mm (3.5 in)
1952
97.5 mm (3.8 in)
1953
88.9 mm (3.5 in)
1954
47.0 mm (1.9 in)
1955
121.2 mm (4.8 in)
1956
56.6 mm (2.2 in)
1957
55.9 mm (2.2 in)
1958
108.2 mm (4.3 in)
1959
61.0 mm (2.4 in)
1960
86.9 mm (3.4 in)
1961
108.0 mm (4.3 in)
1962
49.8 mm (2.0 in)
1963
48.0 mm (1.9 in)
1964
68.6 mm (2.7 in)
1965
99.1 mm (3.9 in)
1966
37.6 mm (1.5 in)
1967
50.8 mm (2.0 in)
1968
61.0 mm (2.4 in)
1969
67.3 mm (2.6 in)
1970
72.4 mm (2.9 in)
1971
47.0 mm (1.9 in)
1972
63.8 mm (2.5 in)
1973
76.2 mm (3.0 in)
1974
62.0 mm (2.4 in)
1975
104.1 mm (4.1 in)
1976
53.3 mm (2.1 in)
1977
77.5 mm (3.1 in)
1978
49.5 mm (1.9 in)
1979
57.2 mm (2.3 in)
1980
68.3 mm (2.7 in)
1981
81.3 mm (3.2 in)
1982
139.7 mm (5.5 in)
1983
104.1 mm (4.1 in)
1984
100.6 mm (4.0 in)
1985
107.7 mm (4.2 in)
1986
115.3 mm (4.5 in)
1987
85.9 mm (3.4 in)
1988
62.0 mm (2.4 in)
1989
50.3 mm (2.0 in)
1990
124.0 mm (4.9 in)
1991
48.3 mm (1.9 in)
1992
65.0 mm (2.6 in)
1993
152.4 mm (6.0 in)
1994
66.0 mm (2.6 in)
1995
99.1 mm (3.9 in)
1996
66.0 mm (2.6 in)
1997
87.9 mm (3.5 in)
1998
62.5 mm (2.5 in)
1999
40.1 mm (1.6 in)
2000
87.6 mm (3.4 in)
2001
74.2 mm (2.9 in)
2002
86.4 mm (3.4 in)
2003
121.9 mm (4.8 in)
2004
83.8 mm (3.3 in)
2005
53.3 mm (2.1 in)
2006
66.3 mm (2.6 in)
2007
56.9 mm (2.2 in)
2008
44.2 mm (1.7 in)
Wettest five days (Rx5day)
The wettest five days of the year at Boonville, 1937 to 2008. The record is 242.3 mm (9.5 in) in 1985, marked on the chart; the median year is 108.2 mm (4.3 in).
Wettest five days (Rx5day) at Boonville by year
Year
Wettest five days (Rx5day)
1937
33.5 mm (1.3 in)
1938
114.0 mm (4.5 in)
1939
124.2 mm (4.9 in)
1940
99.6 mm (3.9 in)
1941
119.5 mm (4.7 in)
1942
179.8 mm (7.1 in)
1943
157.7 mm (6.2 in)
1944
108.9 mm (4.3 in)
1945
144.6 mm (5.7 in)
1946
132.9 mm (5.2 in)
1947
100.5 mm (4.0 in)
1948
107.4 mm (4.2 in)
1949
104.8 mm (4.1 in)
1950
97.1 mm (3.8 in)
1951
97.5 mm (3.8 in)
1952
104.1 mm (4.1 in)
1953
89.4 mm (3.5 in)
1954
75.6 mm (3.0 in)
1955
144.3 mm (5.7 in)
1956
76.4 mm (3.0 in)
1957
80.8 mm (3.2 in)
1958
145.3 mm (5.7 in)
1959
82.6 mm (3.3 in)
1960
115.3 mm (4.5 in)
1961
134.2 mm (5.3 in)
1962
57.8 mm (2.3 in)
1963
76.4 mm (3.0 in)
1964
99.3 mm (3.9 in)
1965
156.6 mm (6.2 in)
1966
67.4 mm (2.7 in)
1967
103.7 mm (4.1 in)
1968
126.3 mm (5.0 in)
1969
169.7 mm (6.7 in)
1970
151.2 mm (6.0 in)
1971
62.7 mm (2.5 in)
1972
71.1 mm (2.8 in)
1973
116.4 mm (4.6 in)
1974
86.2 mm (3.4 in)
1975
114.8 mm (4.5 in)
1976
79.7 mm (3.1 in)
1977
139.5 mm (5.5 in)
1978
77.5 mm (3.1 in)
1979
106.3 mm (4.2 in)
1980
110.5 mm (4.4 in)
1981
181.0 mm (7.1 in)
1982
227.6 mm (9.0 in)
1983
217.2 mm (8.6 in)
1984
160.2 mm (6.3 in)
1985
242.3 mm (9.5 in)
1986
242.3 mm (9.5 in)
1987
85.9 mm (3.4 in)
1988
70.1 mm (2.8 in)
1989
79.8 mm (3.1 in)
1990
170.2 mm (6.7 in)
1991
84.4 mm (3.3 in)
1992
101.1 mm (4.0 in)
1993
154.7 mm (6.1 in)
1994
124.0 mm (4.9 in)
1995
192.6 mm (7.6 in)
1996
93.5 mm (3.7 in)
1997
92.0 mm (3.6 in)
1998
91.0 mm (3.6 in)
1999
68.0 mm (2.7 in)
2000
118.3 mm (4.7 in)
2001
140.2 mm (5.5 in)
2002
173.0 mm (6.8 in)
2003
156.5 mm (6.2 in)
2004
99.8 mm (3.9 in)
2005
128.4 mm (5.1 in)
2006
91.9 mm (3.6 in)
2007
126.7 mm (5.0 in)
2008
75.7 mm (3.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at Boonville, 1937 to 2008. The record is 45 days in 1964, marked on the chart; the median year is 23 days.
Longest dry spell (CDD) at Boonville by year
Year
Longest dry spell (CDD)
1937
11 days
1938
30 days
1939
21 days
1940
17 days
1941
27 days
1942
15 days
1943
28 days
1944
19 days
1945
25 days
1946
22 days
1947
24 days
1948
24 days
1949
17 days
1950
31 days
1951
19 days
1952
24 days
1953
23 days
1954
23 days
1955
29 days
1956
29 days
1957
22 days
1958
28 days
1959
16 days
1960
18 days
1961
18 days
1962
17 days
1963
19 days
1964
45 days
1965
20 days
1966
18 days
1967
25 days
1968
19 days
1969
18 days
1970
26 days
1971
31 days
1972
29 days
1973
16 days
1974
21 days
1975
14 days
1976
23 days
1977
26 days
1978
22 days
1979
43 days
1980
27 days
1981
20 days
1982
21 days
1983
26 days
1984
27 days
1985
24 days
1986
32 days
1987
21 days
1988
21 days
1989
29 days
1990
18 days
1991
30 days
1992
26 days
1993
23 days
1994
23 days
1995
29 days
1996
34 days
1997
17 days
1998
23 days
1999
41 days
2000
31 days
2001
18 days
2002
32 days
2003
42 days
2004
24 days
2005
22 days
2006
30 days
2007
29 days
2008
22 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
65 years with a frost
Across 65 years with a frost, the median last spring frost at Boonville falls on 10 April and the median first autumn frost on 28 October, which leaves a median of 199 days between them.
In 1975 to 2007 the median growing season was 197 days. That is 2 days fewer than in 1938 to 1967.
Fitted over all years, the growing season changes by -0.6 days per decade at this station.
Frost dates and growing season at Boonville
Measure
Median, all years
Earliest period (1938 to 1967)
Recent period (1975 to 2007)
Recent against earliest
Fitted trend
Last spring frost
10 April
12 April
8 April
4 days earlier
-0.6 days per decade
First autumn frost
28 October
31 October
20 October
11 days earlier
-1.2 days per decade
Growing days
199 days
199 days
197 days
2 days fewer
-0.6 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
68 years, 1938 to 2007
A day with at least 72.6 mm (2.9 in) of rain is expected about once in 2 years. A day with at least 173.5 mm (6.8 in) of rain is expected about once in 100 years.
Rainfall return levels at Boonville: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
72.6 mm (2.9 in)
5 years
97.1 mm (3.8 in)
10 years
114.2 mm (4.5 in)
25 years
137.1 mm (5.4 in)
50 years
155.0 mm (6.1 in)
100 years
173.5 mm (6.8 in)
Longer than the 68 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, 68 years of values from 1938 to 2007.
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: 177.8 mm (7.0 in) in 1942; 152.4 mm (6.0 in) in 1993; 139.7 mm (5.5 in) in 1982.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of Boonville, at 1995. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1995 ran 0.4 C (0.8 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at Boonville, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1995
+0.4
+0.8
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for Boonville standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Boonville 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.