Choteau(OK)
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Choteau(OK) clear sky chart from 2005-11-05 to 2019-07-16.

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
40%
18218
26%
54206
15%
18171
51%
18171
34%
31068

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 15thNight
27%
1050
27%
2717
10%
1045
39%
1045
31%
1694
January16th to endNight
29%
1120
31%
2912
10%
1120
42%
1120
36%
1685
February1st to 15thNight
24%
1030
22%
2678
6%
1026
33%
1026
29%
1671
February16th to endNight
22%
695
25%
2165
7%
695
36%
695
25%
1301
March1st to 15thNight
26%
630
25%
2310
11%
630
42%
630
22%
1365
March16th to endNight
27%
672
21%
2464
12%
672
40%
672
24%
1429
April1st to 15thNight
27%
629
24%
2206
13%
629
45%
629
27%
1242
April16th to endNight
29%
624
22%
2002
12%
624
44%
624
27%
1182
May1st to 15thNight
34%
630
22%
1890
15%
630
45%
630
29%
1173
May16th to endNight
43%
659
20%
1972
15%
657
53%
657
33%
1158
June1st to 15thNight
60%
630
22%
1890
18%
630
66%
630
44%
999
June16th to endNight
62%
630
24%
1890
17%
630
70%
630
48%
956
July1st to 15thNight
68%
600
20%
1800
19%
600
70%
600
43%
973
July16th to endNight
77%
615
28%
1747
31%
582
81%
582
48%
887
August1st to 15thNight
77%
575
27%
1717
30%
572
80%
572
46%
891
August16th to endNight
72%
621
26%
1977
28%
621
75%
621
40%
1045
September1st to 15thNight
64%
585
27%
2067
29%
585
68%
585
34%
1098
September16th to endNight
60%
582
31%
2145
28%
582
68%
582
36%
1065
October1st to 15thNight
44%
744
28%
2304
18%
744
53%
744
36%
1304
October16th to endNight
43%
832
34%
2496
18%
832
55%
832
42%
1303
November1st to 15thNight
34%
845
31%
2485
13%
845
49%
845
36%
1369
November16th to endNight
29%
1050
30%
2730
11%
1050
42%
1050
36%
1628
December1st to 15thNight
29%
1050
26%
2730
9%
1050
40%
1050
30%
1720
December16th to endNight
27%
1120
25%
2912
9%
1120
38%
1120
28%
1930

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
11%5%2442445%7%46%
55104
Night
10%424323447%52%
54402
TransparencyDay
36%412%25%17%3
54804
Night
31%311%26%21%5%
54207
SeeingDay
13%9%27%28%17%4
8198
Night
13%11%31%29%13%1
18218

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 15thDay
12%8%34322235%50%
1881
16th to endDay
12%6%24323335%52%
2016
February1st to 15thDay
14%8%35%5%23345%43%
1845
16th to endDay
16%7%35%424346%43%
1889
March1st to 15thDay
13%7%35%323345%45%
2310
16th to endDay
19%7%36%424446%38%
2462
April1st to 15thDay
12%7%25%43445%6%42%
2402
16th to endDay
16%7%36%5%23346%40%
2560
May1st to 15thDay
16%6%25%6%24446%39%
2721
16th to endDay
9%5%25%6%25%6%6%9%39%
2846
June1st to 15thDay
7%325%436%5%5%8%47%
2730
16th to endDay
6%213425%47%10%50%
2730
July1st to 15thDay
7%3245%45%7%8%10%41%
2730
16th to endDay
5%3145%35%5%6%11%49%
2677
August1st to 15thDay
5%423435%6%7%10%47%
2486
16th to endDay
6%324436%46%9%47%
2575
September1st to 15thDay
12%5%245%2445%7%44%
2220
16th to endDay
9%4134245%5%7%50%
2145
October1st to 15thDay
15%423322245%51%
1973
16th to endDay
10%313222345%59%
2080
November1st to 15thDay
11%413323346%54%
2030
16th to endDay
13%6%22212337%53%
1890
December1st to 15thDay
16%6%24423345%46%
1890
16th to endDay
14%8%35%423345%44%
2016
January1st to 15thNight
12%5%24322345%51%
2717
16th to endNight
9%424212345%57%
2912
February1st to 15thNight
12%7%25%322246%49%
2668
16th to endNight
15%5%24323345%48%
2165
March1st to 15thNight
13%6%25%324445%47%
2310
16th to endNight
14%5%24423346%47%
2464
April1st to 15thNight
12%5%2342345%5%51%
2206
16th to endNight
14%425%422345%49%
2002
May1st to 15thNight
11%425%434447%47%
1889
16th to endNight
8%4244235%7%11%44%
1971
June1st to 15thNight
42234235%5%9%56%
1890
16th to endNight
311232446%9%60%
1890
July1st to 15thNight
5%3134235%7%11%51%
1890
16th to endNight
32133244411%57%
1855
August1st to 15thNight
32123245%8%10%55%
1727
16th to endNight
4313435%5%5%9%53%
1977
September1st to 15thNight
10%5%23313347%53%
2067
16th to endNight
7%3143235%46%56%
2145
October1st to 15thNight
11%414333346%52%
2304
16th to endNight
9%33213335%62%
2496
November1st to 15thNight
11%413312325%58%
2485
16th to endNight
10%5%2431233456%
2730
December1st to 15thNight
14%5%24323346%49%
2730
16th to endNight
14%7%26%423335%45%
2912

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 15thDay
38%29%27%19%2
1882
16th to endDay
35%29%30%18%3
2016
February1st to 15thDay
43%312%24%13%2
1846
16th to endDay
43%29%25%14%4
1889
March1st to 15thDay
40%39%21%18%6%
2310
16th to endDay
48%39%22%13%1
2464
April1st to 15thDay
41%412%23%14%3
2402
16th to endDay
45%410%21%16%1
2560
May1st to 15thDay
45%412%20%15%1
2721
16th to endDay
38%6%15%24%13%
2850
June1st to 15thDay
33%6%12%29%16%1
2730
16th to endDay
26%6%16%29%17%3
2730
July1st to 15thDay
33%8%15%28%13%
2591
16th to endDay
27%5%16%33%16%1
2522
August1st to 15thDay
29%6%14%24%20%4
2472
16th to endDay
31%5%14%28%15%4
2575
September1st to 15thDay
37%5%11%22%15%8%
2220
16th to endDay
31%410%26%22%5%
2145
October1st to 15thDay
35%210%23%21%5%
1973
16th to endDay
27%28%29%23%7%
2080
November1st to 15thDay
31%210%26%21%6%
2030
16th to endDay
33%28%26%25%3
1890
December1st to 15thDay
39%210%27%18%1
1890
16th to endDay
43%310%23%15%3
2016
January1st to 15thNight
35%39%26%22%2
2717
16th to endNight
29%210%30%22%5%
2912
February1st to 15thNight
37%112%26%18%3
2678
16th to endNight
39%28%24%20%4
2165
March1st to 15thNight
39%49%18%20%7%
2310
16th to endNight
37%411%26%17%2
2464
April1st to 15thNight
34%410%24%20%6%
2206
16th to endNight
37%39%25%20%4
2002
May1st to 15thNight
36%5%12%21%18%3
1890
16th to endNight
31%6%17%25%17%1
1973
June1st to 15thNight
24%415%31%21%2
1890
16th to endNight
19%6%12%32%24%4
1890
July1st to 15thNight
24%6%15%30%21%1
1800
16th to endNight
21%412%36%21%3
1747
August1st to 15thNight
21%6%14%28%24%4
1717
16th to endNight
25%5%12%29%20%6%
1977
September1st to 15thNight
30%49%25%19%10%
2067
16th to endNight
27%48%27%26%5%
2145
October1st to 15thNight
32%312%20%21%9%
2304
16th to endNight
25%27%24%29%9%
2496
November1st to 15thNight
29%28%25%25%8%
2485
16th to endNight
32%27%25%27%5%
2730
December1st to 15thNight
37%211%25%20%3
2730
16th to endNight
41%310%21%18%4
2912

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 15thDay
25%14%38%17%4
180
16th to endDay
11%29%34%14%8%
192
February1st to 15thDay
21%22%40%14%1
180
16th to endDay
30%25%32%11%
159
March1st to 15thDay
19%29%35%12%2
180
16th to endDay
21%22%31%19%4
192
April1st to 15thDay
17%19%40%16%7%
281
16th to endDay
23%16%31%18%8%
452
May1st to 15thDay
18%13%35%23%6%1
618
16th to endDay
14%9%39%21%11%3
677
June1st to 15thDay
7%425%38%21%2
645
16th to endDay
7%227%38%20%4
645
July1st to 15thDay
8%116%39%25%8%
625
16th to endDay
6%18%35%37%11%
597
August1st to 15thDay
8%112%38%32%6%
549
16th to endDay
8%215%39%26%7%
487
September1st to 15thDay
8%113%33%34%8%
255
16th to endDay
15%19%35%21%8%
180
October1st to 15thDay
16%9%33%25%12%2
180
16th to endDay
10%10%41%24%10%1
192
November1st to 15thDay
21%13%28%21%12%1
180
16th to endDay
23%18%35%18%31
180
December1st to 15thDay
21%16%42%11%5%2
180
16th to endDay
21%23%36%13%4
192
January1st to 15thNight
16%19%33%24%5%
1050
16th to endNight
12%18%36%27%4
1120
February1st to 15thNight
17%19%36%23%3
1030
16th to endNight
18%17%39%21%3
695
March1st to 15thNight
17%15%38%25%3
630
16th to endNight
15%13%41%23%5%
672
April1st to 15thNight
14%16%38%24%5%
629
16th to endNight
16%11%39%23%8%
624
May1st to 15thNight
14%8%37%30%8%
630
16th to endNight
10%6%34%28%18%1
659
June1st to 15thNight
5%224%40%23%1
630
16th to endNight
3227%42%22%1
630
July1st to 15thNight
6%115%43%29%3
600
16th to endNight
49%41%39%4
615
August1st to 15thNight
5%112%43%33%4
575
16th to endNight
7%112%42%31%3
621
September1st to 15thNight
13%214%41%25%2
585
16th to endNight
9%320%34%28%4
582
October1st to 15thNight
13%433%26%18%2
744
16th to endNight
11%11%32%31%12%1
832
November1st to 15thNight
13%14%34%25%11%
845
16th to endNight
14%17%36%22%8%
1050
December1st to 15thNight
16%17%33%25%6%
1050
16th to endNight
19%15%34%25%4
1120
Page generated at 2019-07-17 07:53:06. Version ac04

Copyright 2019 A. Danko


Choteau(OK) Clear Sky Chart |Charts Home