The following tables present IEM computed monthly data summaries based on
daily data provided by or computed for the IEM. A download interface
exists for the daily summary information. The climatology is provided by the
nearest NCEI climate station () within the current 1991-2020
dataset.
To load shown data into Microsoft Excel,
highlight the table information with your mouse and then copy/paste into Excel.
Precipitation Totals [inch]
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1986
M
M
M
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1987
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1988
0.00
M
M
M
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1989
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1990
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1991
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1992
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1993
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1994
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1995
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1996
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1997
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1998
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1999
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2000
0.05
0.00
0.03
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2001
0.00
0.00
0.00
0.00
0.00
0.00
2.65
7.35
7.51
6.19
0.11
8.06
2002
6.56
6.36
4.97
0.23
0.00
2.05
1.92
3.02
4.64
4.94
9.67
5.65
2003
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
2004
M
M
M
M
M
M
M
M
M
M
M
M
2005
M
M
M
M
M
M
M
M
M
M
M
M
2006
M
M
M
M
M
M
M
M
M
M
M
0.02
2007
0.04
0.09
1.50
6.39
1.39
2.52
2.69
1.08
7.35
10.10
6.44
5.55
2008
4.88
6.01
5.45
3.41
4.04
3.38
5.41
6.41
2.54
6.16
M
5.67
2009
6.04
2.67
4.90
3.04
3.07
2.91
1.66
3.70
6.62
10.28
4.99
2.74
2010
8.02
12.11
9.36
4.66
1.46
3.32
0.95
2.68
3.28
10.13
8.43
5.81
2011
6.66
2.87
3.78
3.17
3.47
2.04
2.06
3.58
6.35
7.14
10.13
8.54
2012
8.57
3.09
4.20
5.45
4.58
5.57
4.34
1.76
3.00
4.84
1.98
3.21
2013
6.63
3.83
0.97
2.58
2.61
2.78
1.25
2.54
4.41
3.93
6.35
8.09
2014
4.62
3.86
11.61
12.56
3.29
2.52
4.27
2.59
4.05
16.49
9.55
9.13
2015
10.27
2.42
M
M
M
M
4.10
4.71
6.36
15.84
6.19
8.28
2016
6.76
16.57
7.03
M
M
0.00
1.02
1.86
7.30
3.39
11.98
10.70
2017
5.55
M
M
M
M
M
1.47
6.93
6.03
7.00
8.49
7.29
2018
5.97
5.68
1.74
4.13
2.32
3.30
0.34
1.52
1.90
0.90
M
M
2019
3.81
1.04
M
5.08
1.70
4.35
2.50
3.97
3.45
9.30
8.79
3.34
2020
3.68
3.32
4.54
5.22
2.31
2.88
5.37
2.49
M
M
M
M
2021
M
M
M
M
M
M
M
M
M
M
M
M
2022
M
M
M
M
M
M
M
M
M
M
M
M
2023
M
M
M
M
M
0.40
2.50
1.20
5.39
5.97
13.12
26.31
2024
1.41
M
M
M
M
M
M
1.86
7.49
8.04
10.21
19.87
2025
5.80
5.27
7.34
3.74
9.20
5.01
2.83
M
M
M
M
M
Average Wind Speed [MPH]
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1986
M
M
M
15.3
14.3
14.8
16.2
10.6
12.1
19.8
19.4
18.4
1987
19.2
18.9
15.5
17.2
20.1
16.5
13.1
15.2
14.8
14.1
20.1
20.7
1988
15.3
M
M
M
16.8
14.9
12.1
14.1
13.7
16.0
20.4
17.2
1989
19.0
15.8
16.6
13.9
12.7
18.2
12.9
11.5
11.6
16.1
17.4
17.0
1990
18.5
16.4
16.3
14.6
15.8
13.0
13.3
15.0
11.8
18.7
16.6
16.5
1991
16.8
18.1
14.9
17.3
17.1
14.0
13.0
16.2
13.3
16.2
21.4
20.3
1992
20.6
19.4
15.2
15.3
16.6
13.8
14.6
14.9
15.9
16.0
20.0
19.2
1993
17.3
18.0
16.7
17.2
13.3
11.8
15.9
13.3
1.6
9.9
16.7
21.9
1994
16.4
17.9
17.3
16.4
19.0
15.1
16.6
12.7
15.3
15.8
18.0
19.7
1995
19.3
18.2
20.4
18.5
15.6
16.9
14.3
11.6
14.0
19.0
20.3
21.5
1996
17.5
16.4
19.1
18.6
15.9
13.0
M
M
M
M
M
M
1997
M
M
M
M
M
M
M
M
M
M
M
M
1998
M
M
M
M
M
M
M
M
M
M
M
M
1999
M
M
M
M
M
M
M
M
18.1
19.3
24.3
17.4
2000
13.4
16.2
20.7
16.1
16.3
12.9
15.4
14.6
12.1
17.3
19.9
21.1
2001
24.4
18.0
18.8
16.1
20.6
15.6
16.1
18.9
17.5
17.4
14.0
15.8
2002
7.4
0.0
4.7
15.8
19.0
18.4
12.1
16.9
14.0
15.8
20.3
22.5
2003
21.1
13.2
21.2
16.2
16.7
18.2
12.3
13.4
15.3
19.0
16.8
21.6
2004
22.3
19.1
18.9
15.2
14.2
15.0
13.6
9.5
14.1
19.6
17.9
19.4
2005
19.6
15.4
19.7
18.3
15.8
15.5
14.7
12.5
13.3
19.7
20.0
21.0
2006
20.3
20.1
16.4
16.5
16.0
17.2
15.8
11.9
15.7
14.1
19.6
27.0
2007
21.3
18.1
19.1
19.6
14.9
17.6
14.3
12.5
14.5
19.1
19.5
20.9
2008
18.6
20.2
22.2
17.0
17.3
16.3
16.7
16.8
14.2
20.9
M
20.1
2009
18.6
16.2
18.4
18.6
13.3
13.2
16.5
16.4
18.1
17.2
19.5
18.2
2010
21.7
19.1
21.6
16.8
14.7
17.9
15.3
13.8
14.4
19.9
21.2
19.1
2011
18.9
20.0
17.9
15.0
15.1
12.1
12.9
13.2
19.0
17.4
18.6
17.6
2012
19.9
17.4
17.1
16.9
18.8
14.4
14.9
9.3
13.1
15.5
19.8
17.1
2013
16.6
18.5
12.8
15.0
14.2
11.9
11.9
14.3
14.0
12.7
16.5
17.3
2014
17.5
18.4
17.9
17.8
13.9
15.3
15.7
12.1
14.9
19.4
15.8
20.8
2015
21.2
16.5
14.8
17.7
15.9
13.6
12.4
11.7
12.9
17.1
17.4
18.2
2016
22.7
21.3
18.9
16.1
16.0
13.9
13.5
14.7
13.1
15.9
21.4
16.6
2017
18.1
18.7
15.6
14.9
15.3
15.1
10.9
16.6
12.0
14.1
18.4
18.1
2018
20.2
15.1
13.2
18.5
13.4
15.9
15.1
13.4
13.2
14.3
M
M
2019
16.5
19.0
11.8
15.9
15.7
13.5
10.6
13.9
13.1
16.6
17.6
18.0
2020
19.8
17.1
16.7
16.0
14.6
16.7
12.5
14.1
12.5
13.7
18.3
22.8
2021
21.3
18.0
16.7
13.2
15.2
14.2
12.6
13.4
17.7
17.4
19.2
16.1
2022
19.3
17.9
15.5
16.4
14.7
14.2
12.9
13.9
15.1
15.6
19.0
17.1
2023
18.9
20.7
17.2
18.0
14.5
13.5
12.5
11.6
17.8
17.6
17.5
21.7
2024
19.4
14.1
13.7
12.7
14.2
14.9
11.3
14.1
11.2
17.4
18.2
21.9
2025
16.5
18.5
16.4
15.5
20.2
15.6
13.7
M
M
M
M
M
Average Daily High Temperature [F]
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1986
M
M
M
46.50
49.19
54.17
55.97
58.03
56.20
54.55
46.14
45.52
1987
44.07
45.07
43.81
46.63
49.74
53.27
56.61
58.26
56.10
52.16
48.43
43.65
1988
41.80
M
M
M
50.10
53.77
56.84
57.65
55.67
52.55
46.50
42.61
1989
39.77
37.93
41.81
47.00
51.00
54.40
59.13
58.55
58.13
52.19
46.60
46.74
1990
41.97
39.18
43.71
47.40
51.00
56.23
59.81
61.29
58.57
50.13
42.37
39.90
1991
37.65
43.79
41.13
45.50
49.29
53.00
56.48
58.32
56.70
50.10
48.03
45.61
1992
44.94
44.24
44.87
47.57
50.52
54.83
56.90
59.00
54.70
50.68
47.93
41.03
1993
39.90
43.68
44.65
48.97
52.84
57.03
57.55
59.26
56.27
53.39
49.35
26.00
1994
18.00
M
M
M
50.45
54.03
57.35
59.84
57.07
50.68
42.53
40.81
1995
42.52
41.11
41.77
48.03
51.45
54.97
57.23
58.10
58.43
51.55
45.50
40.81
1996
35.61
40.62
42.48
46.67
51.23
53.19
55.03
57.67
54.59
49.17
40.38
35.79
1997
38.92
42.64
41.29
46.78
52.24
55.18
58.81
59.90
59.24
51.47
47.07
45.65
1998
40.33
48.40
43.25
44.80
51.44
62.00
58.08
58.70
56.23
52.39
46.32
41.89
1999
40.35
41.44
42.69
45.17
47.25
52.52
53.73
60.00
54.52
51.06
45.97
43.00
2000
38.99
42.44
45.12
46.60
49.72
55.69
58.48
57.97
55.70
52.33
47.97
42.53
2001
44.42
42.28
43.25
47.04
49.25
54.13
56.16
58.29
55.40
50.08
38.73
41.55
2002
42.17
41.39
38.81
44.15
48.91
54.60
57.48
59.08
56.71
52.38
49.87
46.71
2003
46.25
44.05
42.78
47.47
51.79
54.88
59.69
60.86
58.07
53.70
45.49
43.59
2004
M
44.15
M
M
M
58.46
59.23
61.91
55.83
50.22
44.56
41.31
2005
40.28
42.81
45.44
49.31
55.24
57.55
59.56
M
47.50
52.27
43.12
39.96
2006
38.10
35.27
36.57
41.82
48.05
52.75
54.85
56.11
53.11
46.50
36.05
39.79
2007
40.08
43.58
42.79
46.58
51.38
55.54
59.78
61.95
57.09
51.06
45.47
38.94
2008
38.96
41.23
42.60
44.68
49.80
52.85
56.37
57.72
55.92
50.66
M
37.91
2009
39.85
39.37
40.15
45.77
51.28
56.21
57.94
59.54
56.42
51.70
45.22
40.16
2010
43.99
45.31
44.86
47.61
52.08
54.94
57.92
58.60
57.87
52.50
44.80
41.83
2011
40.71
38.80
42.76
45.59
50.53
55.80
57.26
58.43
55.47
50.09
42.44
41.68
2012
37.32
41.39
40.88
46.74
48.25
53.25
56.27
60.13
56.79
48.86
45.88
41.27
2013
43.33
44.33
43.91
47.65
52.77
57.85
59.95
61.76
59.22
53.06
45.89
43.31
2014
44.93
38.96
41.96
48.03
53.70
57.13
60.82
63.09
60.33
54.83
47.37
45.95
2015
46.21
47.45
49.12
49.71
54.46
60.00
62.84
62.38
57.63
54.67
46.49
43.44
2016
45.56
47.30
49.07
51.58
55.70
58.43
61.75
61.94
58.98
54.06
48.90
39.27
2017
41.89
40.54
41.68
50.09
52.85
56.38
59.88
60.36
59.29
53.35
44.30
42.74
2018
43.26
40.36
44.30
47.78
53.21
57.30
60.64
61.90
59.57
53.10
M
M
2019
42.01
40.50
46.77
49.14
53.34
57.17
62.65
61.98
59.50
52.06
49.21
45.00
2020
38.61
42.54
43.32
46.92
55.05
56.78
61.43
60.84
59.53
51.99
45.87
45.46
2021
43.48
39.81
43.44
49.08
52.38
58.41
61.38
61.69
57.89
50.48
46.20
35.95
2022
40.64
43.61
45.93
48.55
52.21
58.01
60.85
63.62
60.02
54.34
43.08
37.96
2023
44.06
41.34
42.86
48.04
54.66
58.16
61.67
63.75
59.33
53.12
48.56
45.75
2024
41.07
43.82
45.93
50.12
53.78
58.50
61.93
62.40
58.88
52.11
45.81
45.53
2025
43.82
39.76
47.21
50.32
53.34
57.17
59.79
M
M
M
M
M
Average Daily Low Temperature [F]
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1986
M
M
M
40.67
43.90
48.60
52.58
54.23
51.17
50.23
40.36
41.55
1987
39.52
40.46
38.55
41.03
45.71
48.80
52.16
54.26
51.38
46.84
43.50
38.10
1988
38.40
M
M
M
45.40
49.00
51.74
53.84
50.47
47.10
41.47
37.68
1989
33.10
33.07
36.45
41.33
45.84
49.67
54.19
54.39
52.90
46.55
39.90
42.58
1990
36.26
32.96
39.55
43.17
46.29
50.83
54.29
56.45
53.13
44.06
36.33
32.87
1991
33.19
37.96
35.65
40.27
44.35
47.83
52.03
53.26
52.77
45.00
42.90
40.39
1992
40.06
39.28
40.39
41.87
46.39
49.93
52.97
54.13
49.20
45.29
42.70
34.42
1993
34.00
38.93
38.42
43.47
47.71
51.00
53.39
53.94
51.83
47.45
43.55
25.00
1994
18.00
M
M
M
45.27
49.07
53.42
54.42
51.73
44.10
35.47
36.06
1995
38.42
35.68
36.32
41.77
46.26
49.50
52.48
52.55
54.00
45.42
40.23
35.84
1996
30.03
35.45
37.68
41.50
45.81
49.44
52.07
53.93
50.93
45.60
36.93
32.00
1997
36.12
40.24
37.00
42.63
47.83
51.29
55.29
56.55
55.48
47.13
43.43
41.00
1998
36.44
41.88
39.36
41.04
47.12
58.12
53.72
54.96
52.53
48.42
42.79
38.43
1999
36.87
36.41
38.00
40.92
43.08
48.70
50.55
55.00
51.22
44.81
40.47
38.10
2000
34.44
38.33
39.63
41.19
44.79
49.96
53.87
54.11
49.93
46.02
42.52
37.24
2001
39.63
37.57
37.46
40.19
43.27
48.74
51.18
53.88
50.94
43.82
33.72
36.35
2002
37.30
35.97
33.54
39.08
43.57
48.47
51.64
54.17
50.69
46.93
45.52
41.47
2003
5.75
16.84
35.18
38.00
45.27
49.33
52.23
54.33
51.60
47.52
38.19
38.34
2004
M
40.65
M
M
M
57.40
57.20
60.59
55.03
48.82
43.24
39.82
2005
34.88
37.31
39.36
41.82
48.85
49.28
51.54
M
45.10
45.56
37.15
36.16
2006
33.38
33.27
34.32
40.79
46.42
51.42
52.84
54.22
52.00
45.99
34.15
37.55
2007
32.79
36.62
34.17
39.04
42.10
48.14
52.99
53.34
50.84
43.91
38.29
32.71
2008
32.70
34.72
36.17
37.17
42.97
46.04
50.08
51.77
50.19
43.45
M
32.59
2009
34.17
32.60
32.88
38.57
42.95
48.66
51.72
53.45
50.79
45.02
37.96
34.73
2010
39.03
39.68
37.08
39.91
44.51
48.12
50.82
51.70
49.11
44.42
38.21
36.54
2011
36.14
32.78
35.85
37.82
43.91
48.67
51.11
51.55
49.67
42.11
35.16
34.91
2012
31.09
34.78
32.56
38.47
41.74
46.75
50.13
52.24
49.55
42.95
40.67
35.04
2013
37.98
38.35
35.32
39.79
45.06
49.57
53.41
54.55
51.11
47.25
39.33
36.53
2014
38.86
32.39
34.62
40.14
46.07
49.11
53.54
54.73
53.27
47.71
40.70
39.94
2015
41.00
39.77
40.36
40.79
46.03
50.35
54.85
53.75
48.12
48.36
38.73
37.40
2016
40.89
40.40
40.69
42.67
47.17
50.17
54.59
55.23
50.75
46.34
41.37
33.66
2017
36.15
33.59
32.54
40.90
45.38
48.80
51.96
53.77
51.29
44.48
37.28
37.40
2018
38.03
33.34
36.16
40.12
45.21
49.30
53.25
53.68
51.37
45.66
M
M
2019
36.53
28.32
42.07
39.69
46.14
49.83
53.74
53.95
51.58
44.76
43.78
38.91
2020
31.86
35.74
36.42
40.57
46.43
49.75
53.47
53.97
51.78
43.93
36.96
40.13
2021
37.72
32.71
35.18
38.78
44.43
49.93
52.21
53.34
49.74
42.17
37.82
29.47
2022
35.59
37.93
37.45
37.04
42.91
49.26
53.22
54.74
52.73
47.31
36.50
31.73
2023
38.68
34.10
34.92
37.83
45.28
48.27
52.23
54.58
51.70
46.38
41.49
38.13
2024
36.37
36.03
36.49
38.44
43.22
48.30
53.35
54.09
49.97
43.55
37.57
40.75
2025
38.15
33.39
37.80
40.93
43.84
48.41
50.38
M
M
M
M
M
Average Daily Temperature (high+low)/2 [F]
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1986
M
M
M
43.58
46.55
51.38
54.27
56.13
53.68
52.39
43.25
43.53
1987
41.80
42.77
41.18
43.83
47.73
51.03
54.39
56.26
53.74
49.50
45.97
40.87
1988
40.10
M
M
M
47.75
51.38
54.29
55.74
53.07
49.82
43.98
40.15
1989
36.44
35.50
39.13
44.17
48.42
52.03
56.66
56.47
55.52
49.37
43.25
44.66
1990
39.11
36.07
41.63
45.28
48.65
53.53
57.05
58.87
55.85
47.10
39.35
36.39
1991
35.42
40.88
38.39
42.88
46.82
50.42
54.26
55.79
54.73
47.55
45.47
43.00
1992
42.50
41.76
42.63
44.72
48.45
52.38
54.94
56.56
51.95
47.98
45.32
37.73
1993
36.95
41.30
41.53
46.22
50.27
54.02
55.47
56.60
54.05
50.42
46.45
25.50
1994
18.00
M
M
M
47.86
51.55
55.39
57.13
54.40
47.39
39.00
38.44
1995
40.47
38.39
39.05
44.90
48.85
52.23
54.85
55.32
56.22
48.48
42.87
38.32
1996
32.82
38.03
40.08
44.08
48.52
51.31
53.55
55.80
52.76
47.38
38.66
33.90
1997
37.52
41.44
39.14
44.70
50.03
53.23
57.05
58.22
57.36
49.30
45.25
43.33
1998
38.39
45.14
41.30
42.92
49.28
60.06
55.90
56.83
54.38
50.40
44.55
40.16
1999
38.61
38.93
40.35
43.04
45.17
50.61
52.14
57.50
52.87
47.94
43.22
40.55
2000
36.71
40.38
42.37
43.89
47.25
52.83
56.18
56.04
52.82
49.17
45.24
39.88
2001
42.02
39.92
40.36
43.61
46.26
51.43
53.67
56.09
53.17
46.95
36.23
38.95
2002
39.74
38.68
36.18
41.62
46.24
51.54
54.56
56.63
53.70
49.65
47.70
44.09
2003
26.00
30.44
38.98
42.74
48.53
52.10
55.96
57.59
54.83
50.61
41.84
40.97
2004
M
42.40
M
M
M
57.93
58.21
61.25
55.43
49.51
43.90
40.56
2005
37.58
40.06
42.40
45.56
52.05
53.42
55.55
M
46.30
48.92
40.14
38.06
2006
35.74
34.27
35.45
41.31
47.24
52.09
53.84
55.16
52.56
46.25
35.10
38.67
2007
36.44
40.10
38.48
42.81
46.87
51.84
56.39
57.65
53.96
47.48
41.88
35.82
2008
35.83
37.98
39.39
40.92
46.54
49.45
53.22
54.75
53.05
47.06
M
35.25
2009
37.01
35.99
36.51
42.37
47.28
52.43
54.83
56.49
53.60
48.36
41.59
37.44
2010
41.51
42.50
40.97
43.76
48.30
51.53
54.37
55.15
53.49
48.46
41.51
39.18
2011
38.42
35.79
39.30
41.70
47.22
52.24
54.18
54.99
52.57
46.10
38.80
38.30
2012
34.21
38.09
36.72
42.60
44.99
50.15
53.34
56.18
53.17
45.91
43.28
38.15
2013
40.65
41.34
39.62
43.72
48.91
53.71
56.68
58.16
55.16
50.16
42.61
39.92
2014
41.89
35.67
38.29
44.09
49.89
53.12
57.18
58.91
56.80
51.27
44.04
42.95
2015
43.60
43.61
44.74
45.25
50.25
55.17
58.85
58.07
52.87
51.51
42.61
40.42
2016
43.23
43.85
44.88
47.12
51.43
54.30
58.17
58.59
54.86
50.20
45.13
36.46
2017
39.02
37.06
37.11
45.49
49.12
52.59
55.92
57.07
55.29
48.91
40.79
40.07
2018
40.65
36.85
40.23
43.95
49.21
53.30
56.94
57.79
55.47
49.38
M
M
2019
39.27
34.41
44.42
44.41
49.74
53.50
58.19
57.97
55.54
48.41
46.49
41.95
2020
35.24
39.14
39.87
43.75
50.74
53.27
57.45
57.41
55.66
47.96
41.41
42.80
2021
40.60
36.26
39.31
43.93
48.40
54.17
56.79
57.51
53.82
46.32
42.01
32.71
2022
38.12
40.77
41.69
42.79
47.56
53.63
57.03
59.18
56.38
50.83
39.79
34.85
2023
41.37
37.72
38.89
42.94
49.97
53.21
56.95
59.16
55.52
49.75
45.03
41.94
2024
38.72
39.92
41.21
44.28
48.50
53.40
57.64
58.25
54.42
47.83
41.69
43.14
2025
40.99
36.58
42.51
45.63
48.59
52.79
55.08
M
M
M
M
M
Average Relative Humidity [%]
This value is computed via a simple average of available observations weighted
by the duration between observations.
