Van Meter State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Van Meter State Park clear sky chart from 2005-11-06 to 2024-01-12.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
42%
24476
21%
74707
14%
24415
49%
24415
28%
46707

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 10thNight
28%
950
20%
2530
8%
946
38%
946
27%
1691
January11th to 20thNight
25%
906
19%
2354
8%
906
33%
906
24%
1664
January21st to endNight
26%
990
18%
2574
6%
990
34%
990
24%
1803
February1st to 10thNight
23%
900
14%
2340
5%
900
28%
900
22%
1682
February11th to 20thNight
25%
879
17%
2274
5%
875
33%
875
26%
1550
February21st to endNight
22%
586
22%
1770
6%
586
35%
586
25%
1131
March1st to 10thNight
27%
540
23%
1980
10%
540
42%
540
24%
1164
March11th to 20thNight
29%
540
18%
1980
12%
540
38%
540
18%
1294
March21st to endNight
23%
594
11%
2178
6%
594
31%
594
13%
1563
April1st to 10thNight
32%
540
22%
1814
13%
540
46%
540
27%
1068
April11th to 20thNight
34%
533
22%
1775
17%
533
46%
533
25%
1091
April21st to endNight
33%
540
20%
1766
12%
540
46%
540
23%
1146
May1st to 10thNight
39%
540
16%
1620
11%
540
47%
540
25%
1063
May11th to 20thNight
45%
531
18%
1555
15%
531
50%
531
27%
1012
May21st to endNight
50%
584
20%
1552
12%
582
56%
582
29%
1030
June1st to 10thNight
66%
540
22%
1440
16%
540
69%
540
43%
828
June11th to 20thNight
62%
540
23%
1440
15%
540
66%
540
39%
869
June21st to endNight
64%
540
24%
1440
15%
540
68%
540
48%
788
July1st to 10thNight
72%
525
20%
1400
17%
525
73%
525
41%
834
July11th to 20thNight
72%
522
22%
1545
19%
522
75%
522
44%
823
July21st to endNight
70%
591
24%
1673
23%
558
73%
558
40%
914
August1st to 10thNight
72%
537
22%
1601
24%
534
75%
534
39%
893
August11th to 20thNight
72%
534
28%
1613
31%
534
75%
534
42%
885
August21st to endNight
78%
594
27%
1980
34%
594
79%
594
43%
994
September1st to 10thNight
66%
540
27%
1800
29%
540
69%
540
37%
971
September11th to 20thNight
65%
540
31%
1844
30%
540
70%
540
36%
979
September21st to endNight
61%
598
28%
2038
25%
598
67%
598
37%
1064
October1st to 10thNight
52%
720
26%
2160
20%
720
56%
720
38%
1213
October11th to 20thNight
37%
720
28%
2160
16%
720
46%
720
32%
1277
October21st to endNight
33%
792
24%
2376
12%
792
44%
792
28%
1452
November1st to 10thNight
42%
740
29%
2245
17%
740
54%
740
37%
1227
November11th to 20thNight
34%
861
26%
2571
13%
861
47%
861
32%
1511
November21st to endNight
32%
950
22%
2660
9%
950
42%
950
27%
1737
December1st to 10thNight
31%
950
19%
2660
8%
950
41%
950
26%
1747
December11th to 20thNight
31%
949
19%
3158
8%
948
38%
948
22%
2031
December21st to endNight
23%
1040
11%
4841
6%
1026
34%
1026
10%
3718

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
13%7%36%5%3445%7%43%
74652
Night
13%7%35%43445%7%46%
75069
TransparencyDay
40%6%13%24%14%2
74369
Night
38%5%11%25%17%3
74873
SeeingDay
15%8%26%28%18%6%
14516
Night
15%8%30%33%13%1
24482

By Month

Percentage Cloud Cover SE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
13%10%46%5%3445%6%38%
1631
11th to 20thDay
14%12%5%9%5%35%345%35%
1629
21st to endDay
14%10%49%6%35%45%6%35%
1782
February1st to 10thDay
16%10%5%8%5%34446%34%
1620
11th to 20thDay
14%9%47%6%2445%6%39%
1574
21st to endDay
14%9%46%6%3345%6%39%
1497
March1st to 10thDay
13%9%46%5%3445%6%40%
1980
11th to 20thDay
19%10%5%7%5%34446%34%
1980
21st to endDay
22%11%48%6%3445%6%27%
2178
April1st to 10thDay
15%7%245%3446%7%42%
2146
11th to 20thDay
16%9%36%5%245%5%6%40%
2134
21st to endDay
21%7%37%6%35%446%34%
2190
May1st to 10thDay
16%8%36%5%35%5%5%7%36%
2340
11th to 20thDay
17%6%36%6%3445%7%39%
2337
21st to endDay
13%7%37%7%46%5%6%8%36%
2725
June1st to 10thDay
7%424436%5%7%11%47%
2520
11th to 20thDay
8%425%5%345%7%9%46%
2520
21st to endDay
7%426%5%345%7%9%48%
2520
July1st to 10thDay
8%425%435%5%7%10%45%
2520
11th to 20thDay
5%325%435%6%7%8%53%
2358
21st to endDay
8%5%25%5%35%5%5%9%47%
2546
August1st to 10thDay
8%5%35%5%35%6%7%10%44%
2328
11th to 20thDay
8%435%5%35%46%9%47%
2288
21st to endDay
8%5%234245%7%8%53%
2376
September1st to 10thDay
12%425%4245%5%7%51%
2160
11th to 20thDay
11%32443445%8%53%
2112
21st to endDay
8%5%245%335%46%56%
1904
October1st to 10thDay
12%5%3443445%6%51%
1800
11th to 20thDay
14%7%25%423345%52%
1800
21st to endDay
17%7%35%423346%45%
1980
November1st to 10thDay
11%6%24424347%53%
1830
11th to 20thDay
15%6%25%423347%48%
1606
21st to endDay
17%8%46%423335%44%
1520
December1st to 10thDay
9%9%5%8%5%34447%42%
1520
11th to 20thDay
13%8%47%6%24445%42%
1918
21st to endDay
17%14%7%10%7%34445%25%
2783
January1st to 10thNight
9%10%46%4345%46%44%
2530
11th to 20thNight
13%9%5%7%5%35%5%5%6%38%
2354
21st to endNight
11%9%5%8%6%35%5%5%6%39%
2574
February1st to 10thNight
15%10%47%6%35%45%6%36%
2340
11th to 20thNight
14%8%46%5%34447%41%
2273
21st to endNight
14%9%45%42245%7%43%
1770
March1st to 10thNight
14%8%35%324446%47%
1980
11th to 20thNight
18%8%45%5%345%5%7%37%
1980
21st to endNight
22%10%46%6%35%45%7%29%
2178
April1st to 10thNight
11%7%2442436%6%49%
1814
11th to 20thNight
14%7%25%5%34337%46%
1775
21st to endNight
17%8%36%43435%6%42%
1766
May1st to 10thNight
16%5%36%5%345%6%8%40%
1620
11th to 20thNight
14%6%35%5%35%5%5%8%44%
1554
21st to endNight
11%6%25%5%46%5%7%8%42%
1551
June1st to 10thNight
5%4135%345%5%10%55%
1440
11th to 20thNight
6%2346%45%46%11%50%
1440
21st to endNight
43134245%6%9%58%
1440
July1st to 10thNight
8%4244245%7%8%52%
1440
11th to 20thNight
43143245%7%9%57%
1597
21st to endNight
6%325%5%345%6%10%52%
1772
August1st to 10thNight
5%424435%5%6%10%51%
1611
11th to 20thNight
7%42432436%8%56%
1613
21st to endNight
6%3233245%5%7%61%
1980
September1st to 10thNight
11%424423347%57%
1800
11th to 20thNight
10%32332445%8%55%
1844
21st to endNight
8%324434447%58%
2038
October1st to 10thNight
11%424324445%57%
2160
11th to 20thNight
15%5%24323345%54%
2160
21st to endNight
16%7%2332333450%
2376
November1st to 10thNight
11%5%13323346%58%
2245
11th to 20thNight
12%6%2443335%6%52%
2571
21st to endNight
18%8%24424345%47%
2660
December1st to 10thNight
13%8%36%42435%6%43%
2660
11th to 20thNight
14%7%47%5%3435%5%42%
3279
21st to endNight
21%15%6%9%5%3333427%
4884

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
46%5%12%22%14%1
1632
11th to 20thDay
52%410%24%9%
1629
21st to endDay
50%6%14%19%9%1
1782
February1st to 10thDay
52%5%12%20%10%1
1620
11th to 20thDay
46%5%12%21%12%3
1583
21st to endDay
46%5%13%22%12%2
1497
March1st to 10thDay
45%5%11%25%12%2
1980
11th to 20thDay
52%6%9%22%10%2
1980
21st to endDay
58%6%11%17%7%1
2178
April1st to 10thDay
41%6%12%26%14%1
2146
11th to 20thDay
45%5%12%24%12%2
2134
21st to endDay
50%6%11%21%11%
2190
May1st to 10thDay
48%8%13%20%11%1
2340
11th to 20thDay
46%6%12%24%12%1
2341
21st to endDay
45%9%12%21%11%1
2725
June1st to 10thDay
30%8%16%31%14%1
2520
11th to 20thDay
33%8%13%27%17%2
2520
21st to endDay
30%7%17%28%13%4
2520
July1st to 10thDay
32%9%14%26%15%4
2451
11th to 20thDay
27%8%17%26%18%3
2288
21st to endDay
32%7%13%31%15%1
2405
August1st to 10thDay
32%9%20%25%13%1
2314
11th to 20thDay
32%7%14%30%16%1
2288
21st to endDay
28%7%14%25%20%6%
2376
September1st to 10thDay
32%6%13%25%17%6%
2160
11th to 20thDay
29%7%10%25%24%4
2112
21st to endDay
30%5%10%30%22%3
1904
October1st to 10thDay
33%5%11%25%22%4
1800
11th to 20thDay
36%46%29%21%4
1800
21st to endDay
41%410%22%18%4
1980
November1st to 10thDay
33%414%25%20%4
1830
11th to 20thDay
38%410%25%20%2
1606
21st to endDay
45%39%27%15%
1520
December1st to 10thDay
43%6%11%26%12%1
1520
11th to 20thDay
45%5%14%27%8%2
1915
21st to endDay
63%5%9%15%7%1
2783
January1st to 10thNight
42%5%11%25%16%1
2530
11th to 20thNight
47%6%13%23%11%1
2354
21st to endNight
47%5%15%21%11%2
2574
February1st to 10thNight
50%5%12%19%12%3
2340
11th to 20thNight
44%5%12%21%16%2
2274
21st to endNight
42%412%21%17%4
1770
March1st to 10thNight
39%411%26%17%3
1980
11th to 20thNight
47%5%10%21%13%3
1980
21st to endNight
56%6%12%18%8%1
2178
April1st to 10thNight
35%6%10%27%19%4
1814
11th to 20thNight
40%5%9%28%15%4
1775
21st to endNight
43%6%9%23%17%1
1766
May1st to 10thNight
41%7%13%23%14%2
1620
11th to 20thNight
40%6%14%22%16%1
1555
21st to endNight
39%8%13%24%14%2
1552
June1st to 10thNight
25%7%16%31%17%3
1440
11th to 20thNight
28%8%12%26%21%5%
1440
21st to endNight
21%7%17%32%19%5%
1440
July1st to 10thNight
28%7%14%31%17%4
1400
11th to 20thNight
22%8%14%32%22%3
1545
21st to endNight
26%6%14%36%16%2
1673
August1st to 10thNight
25%9%17%30%17%2
1601
11th to 20thNight
25%6%12%32%22%2
1613
21st to endNight
22%6%13%27%26%7%
1980
September1st to 10thNight
28%5%11%25%24%6%
1800
11th to 20thNight
28%5%11%27%24%5%
1844
21st to endNight
27%5%10%29%25%4
2038
October1st to 10thNight
29%5%9%26%25%6%
2160
11th to 20thNight
34%46%28%21%7%
2160
21st to endNight
38%49%22%23%4
2376
November1st to 10thNight
28%414%26%22%6%
2245
11th to 20thNight
34%39%27%23%4
2571
21st to endNight
42%49%26%16%2
2660
December1st to 10thNight
42%5%13%26%13%1
2660
11th to 20thNight
43%412%28%12%1
3281
21st to endNight
62%5%8%16%8%1
4884

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 10thDay
18%15%34%23%9%
270
11th to 20thDay
33%11%35%20%1
243
21st to endDay
15%16%43%21%5%
264
February1st to 10thDay
26%12%43%18%2
240
11th to 20thDay
20%18%38%17%8%
240
21st to endDay
20%17%40%17%6%1
198
March1st to 10thDay
16%13%49%20%3
240
11th to 20thDay
27%12%30%26%5%
240
21st to endDay
35%19%28%14%4
264
April1st to 10thDay
18%15%33%26%8%1
406
11th to 20thDay
20%13%31%28%7%1
412
21st to endDay
22%11%31%24%10%1
450
May1st to 10thDay
17%11%34%28%9%1
603
11th to 20thDay
21%8%28%27%12%4
625
21st to endDay
16%7%24%26%20%7%
679
June1st to 10thDay
7%316%34%29%11%
630
11th to 20thDay
9%320%37%23%7%
630
21st to endDay
7%5%29%36%19%4
630
July1st to 10thDay
10%213%26%33%15%
621
11th to 20thDay
6%218%35%29%11%
618
21st to endDay
8%213%33%35%9%
684
August1st to 10thDay
8%215%37%31%8%
626
11th to 20thDay
8%314%34%31%10%
602
21st to endDay
10%112%28%33%16%
495
September1st to 10thDay
14%114%32%29%10%
450
11th to 20thDay
8%213%33%31%12%
402
21st to endDay
9%5%26%30%23%8%
270
October1st to 10thDay
17%6%27%27%13%9%
270
11th to 20thDay
12%17%38%24%8%1
270
21st to endDay
27%14%28%24%6%1
297
November1st to 10thDay
17%6%33%28%12%4
270
11th to 20thDay
14%17%32%24%10%2
270
21st to endDay
25%13%28%27%7%
270
December1st to 10thDay
11%16%36%24%11%2
270
11th to 20thDay
17%16%35%22%9%1
270
21st to endDay
23%16%41%18%2
297
January1st to 10thNight
14%12%39%27%7%
950
11th to 20thNight
17%12%39%26%5%1
906
21st to endNight
17%11%39%29%4
990
February1st to 10thNight
18%12%41%26%3
900
11th to 20thNight
19%12%39%27%4
879
21st to endNight
20%12%43%21%41
586
March1st to 10thNight
19%12%39%26%5%
540
11th to 20thNight
22%9%34%28%6%1
540
21st to endNight
27%10%34%25%4
594
April1st to 10thNight
15%11%38%30%5%
540
11th to 20thNight
18%9%33%31%9%
533
21st to endNight
19%8%36%29%8%
540
May1st to 10thNight
17%6%31%36%10%
540
11th to 20thNight
17%428%36%14%1
531
21st to endNight
14%425%34%21%2
584
June1st to 10thNight
7%117%47%23%4
540
11th to 20thNight
7%121%47%21%2
540
21st to endNight
4424%47%21%1
540
July1st to 10thNight
10%28%40%37%3
525
11th to 20thNight
6%115%39%37%2
522
21st to endNight
8%112%42%36%1
591
August1st to 10thNight
6%112%47%31%2
537
11th to 20thNight
6%212%41%36%4
534
21st to endNight
7%19%41%39%3
594
September1st to 10thNight
12%115%41%26%4
540
11th to 20thNight
11%116%39%27%5%
540
21st to endNight
7%5%21%40%25%3
598
October1st to 10thNight
13%5%27%34%19%3
720
11th to 20thNight
17%9%34%31%9%
720
21st to endNight
20%10%34%27%10%
792
November1st to 10thNight
13%9%31%36%10%
740
11th to 20thNight
15%11%38%28%8%
861
21st to endNight
21%10%34%29%6%
950
December1st to 10thNight
17%10%38%29%6%1
950
11th to 20thNight
19%8%34%33%5%
950
21st to endNight
22%13%36%27%3
1045
Page generated at 2024-01-08 21:31:23. Version ac07

Copyright 2024 Attilla Danko


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