Bearbower Sand Prairie Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bearbower Sand Prairie Area clear sky chart from 2005-11-05 to 2019-06-19.

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
38%
18450
18%
53987
11%
18404
45%
18404
25%
35557

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
30%
1050
14%
2926
6%
1045
36%
1045
21%
2071
January16th to endNight
24%
1120
15%
2941
5%
1120
31%
1120
18%
2178
February1st to 15thNight
23%
1029
13%
2678
3%
1026
30%
1026
19%
1966
February16th to endNight
30%
800
18%
2270
7%
800
38%
800
22%
1539
March1st to 15thNight
28%
714
20%
2394
12%
714
37%
714
23%
1498
March16th to endNight
28%
672
12%
2416
6%
672
35%
672
15%
1690
April1st to 15thNight
25%
629
17%
2097
10%
629
36%
629
19%
1409
April16th to endNight
34%
624
18%
2049
13%
624
44%
624
21%
1381
May1st to 15thNight
38%
630
17%
1754
11%
630
44%
630
24%
1221
May16th to endNight
43%
659
17%
1753
7%
657
49%
657
30%
1163
June1st to 15thNight
53%
630
16%
1680
8%
630
57%
630
34%
1063
June16th to endNight
52%
597
17%
1592
8%
597
56%
597
36%
980
July1st to 15thNight
73%
555
20%
1480
12%
555
74%
555
46%
822
July16th to endNight
69%
612
23%
1584
18%
579
71%
579
46%
879
August1st to 15thNight
70%
575
22%
1717
22%
572
73%
572
40%
960
August16th to endNight
64%
621
21%
2019
23%
621
67%
621
33%
1149
September1st to 15thNight
64%
585
27%
1950
28%
585
68%
585
35%
1071
September16th to endNight
54%
668
26%
2124
20%
668
61%
668
36%
1175
October1st to 15thNight
38%
780
22%
2340
15%
780
44%
780
27%
1494
October16th to endNight
35%
832
21%
2513
12%
832
43%
832
26%
1591
November1st to 15thNight
33%
848
23%
2694
14%
848
43%
848
25%
1671
November16th to endNight
27%
1050
17%
2940
7%
1050
35%
1050
24%
1971
December1st to 15thNight
21%
1050
12%
2940
4%
1050
29%
1050
16%
2189
December16th to endNight
23%
1120
13%
3136
5%
1120
31%
1120
15%
2426

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
14%7%36%5%3445%7%37%
54736
Night
13%7%35%5%24446%42%
54160
Cloud CoverDay
14%7%36%5%3445%7%37%
54745
Night
13%7%35%5%24446%41%
54164
TransparencyDay
45%6%13%22%11%1
54426
Night
42%5%12%23%13%1
53988
SeeingDay
17%7%27%26%16%4
8356
Night
17%7%30%31%12%1
18451

By Month

Percentage Cloud Cover NE (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%10%5%8%6%46%5%46%29%
1672
16th to endDay
13%11%7%10%7%36%5%5%6%23%
1985
February1st to 15thDay
13%12%5%8%6%34436%31%
1845
16th to endDay
15%9%37%6%345%5%5%33%
1774
March1st to 15thDay
15%9%36%5%335%5%7%35%
2227
16th to endDay
18%9%45%5%34448%29%
2512
April1st to 15thDay
19%10%37%5%2445%6%30%
2511
16th to endDay
23%9%25%5%33345%32%
2515
May1st to 15thDay
20%8%36%5%35%45%5%30%
2856
16th to endDay
15%5%25%6%345%5%8%36%
3065
June1st to 15thDay
13%5%15%4245%5%8%42%
2940
16th to endDay
11%5%245%3446%9%41%
2776
July1st to 15thDay
6%4245%35%5%6%9%46%
2730
16th to endDay
8%314435%6%6%10%43%
2834
August1st to 15thDay
9%4245%36%5%7%8%43%
2486
16th to endDay
12%5%246%34448%43%
2533
September1st to 15thDay
13%325%313347%51%
2340
16th to endDay
11%425%424446%46%
2149
October1st to 15thDay
19%7%25%412336%41%
1950
16th to endDay
16%7%245%23446%41%
2061
November1st to 15thDay
13%8%35%5%34346%42%
1823
16th to endDay
16%9%35%423346%38%
1680
December1st to 15thDay
17%11%5%10%5%34436%26%
1680
16th to endDay
18%15%5%8%6%34335%23%
1792
January1st to 15thNight
11%10%5%7%6%35%446%35%
2926
16th to endNight
12%10%5%10%6%34436%32%
2941
February1st to 15thNight
12%12%48%5%34345%34%
2675
16th to endNight
14%9%35%5%33346%40%
2270
March1st to 15thNight
15%9%25%5%22326%44%
2382
16th to endNight
17%9%36%7%3445%5%33%
2416
April1st to 15thNight
16%8%36%5%2335%5%38%
2097
16th to endNight
19%6%25%424345%39%
2049
May1st to 15thNight
15%6%25%4345%5%7%38%
1754
16th to endNight
11%6%25%5%2345%7%43%
1752
June1st to 15thNight
10%4244245%7%8%46%
1680
16th to endNight
10%324325%5%7%8%47%
1592
July1st to 15thNight
5%21222446%9%57%
1560
16th to endNight
431342445%9%55%
1683
August1st to 15thNight
6%31432437%9%53%
1727
16th to endNight
10%414424346%53%
2019
September1st to 15thNight
10%31442234457%
1950
16th to endNight
8%323424347%55%
2124
October1st to 15thNight
15%7%25%5%23235%46%
2340
16th to endNight
15%7%25%423335%46%
2513
November1st to 15thNight
13%6%36%423335%46%
2694
16th to endNight
17%7%34423436%41%
2940
December1st to 15thNight
16%11%48%6%34445%30%
2940
16th to endNight
19%12%5%7%6%24345%27%
3136

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
11%11%5%8%6%46%5%46%28%
1672
16th to endDay
13%12%6%9%8%35%5%5%7%23%
1985
February1st to 15thDay
13%12%5%7%6%34445%30%
1845
16th to endDay
15%9%46%5%345%46%33%
1774
March1st to 15thDay
15%10%36%5%235%5%6%35%
2238
16th to endDay
18%9%46%5%35%448%29%
2510
April1st to 15thDay
19%10%37%5%2445%6%30%
2511
16th to endDay
23%9%35%423345%32%
2515
May1st to 15thDay
20%8%36%5%345%5%6%30%
2856
16th to endDay
15%5%26%5%345%5%8%36%
3065
June1st to 15thDay
13%5%25%435%5%5%8%41%
2940
16th to endDay
11%5%245%345%6%9%41%
2776
July1st to 15thDay
6%4245%35%5%6%9%46%
2730
16th to endDay
7%4245%35%5%8%10%43%
2834
August1st to 15thDay
8%5%245%35%6%6%9%43%
2486
16th to endDay
12%5%25%5%3445%8%42%
2533
September1st to 15thDay
12%415%323347%50%
2340
16th to endDay
11%425%4345%46%46%
2149
October1st to 15thDay
19%6%34422336%41%
1950
16th to endDay
16%7%24423446%41%
2061
November1st to 15thDay
13%7%35%5%34346%42%
1823
16th to endDay
16%9%35%424436%38%
1680
December1st to 15thDay
17%12%411%5%24336%27%
1680
16th to endDay
18%15%5%8%7%34335%23%
1792
January1st to 15thNight
11%10%47%6%34446%34%
2926
16th to endNight
11%10%5%10%7%34436%32%
2941
February1st to 15thNight
13%12%47%6%24335%34%
2668
16th to endNight
14%9%35%5%34336%39%
2270
March1st to 15thNight
15%8%35%5%22236%43%
2394
16th to endNight
17%8%46%6%44446%32%
2416
April1st to 15thNight
17%8%35%43335%5%38%
2097
16th to endNight
19%7%26%42445%5%38%
2049
May1st to 15thNight
15%6%245%3445%7%38%
1753
16th to endNight
11%5%35%5%345%5%7%42%
1752
June1st to 15thNight
9%5%244335%5%8%46%
1680
16th to endNight
9%3233345%8%8%46%
1592
July1st to 15thNight
5%21331446%9%57%
1560
16th to endNight
42144245%5%10%55%
1683
August1st to 15thNight
6%31332447%9%52%
1727
16th to endNight
9%5%2342335%6%52%
2019
September1st to 15thNight
9%323422345%56%
1950
16th to endNight
8%323424337%54%
2124
October1st to 15thNight
16%6%25%413235%46%
2340
16th to endNight
14%7%25%423335%46%
2513
November1st to 15thNight
13%7%35%5%24345%46%
2694
16th to endNight
16%8%34424346%41%
2940
December1st to 15thNight
16%11%48%6%34445%30%
2940
16th to endNight
20%12%5%7%5%24346%26%
3136

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
54%5%12%15%9%
1673
16th to endDay
59%5%13%14%6%
1985
February1st to 15thDay
54%5%13%18%7%
1846
16th to endDay
50%6%13%20%7%1
1774
March1st to 15thDay
48%5%14%22%9%
2238
16th to endDay
53%5%13%20%6%
2512
April1st to 15thDay
52%5%12%21%7%
2511
16th to endDay
53%410%19%10%1
2515
May1st to 15thDay
53%6%12%19%7%
2856
16th to endDay
44%8%13%20%11%1
3069
June1st to 15thDay
38%7%14%22%14%1
2940
16th to endDay
38%8%13%23%15%1
2776
July1st to 15thDay
33%7%13%27%13%3
2581
16th to endDay
33%9%17%23%14%2
2670
August1st to 15thDay
35%8%13%27%12%1
2472
16th to endDay
38%6%12%26%14%1
2533
September1st to 15thDay
33%411%27%20%2
2340
16th to endDay
37%5%11%30%13%1
2149
October1st to 15thDay
44%49%22%16%1
1950
16th to endDay
43%5%12%24%13%1
2061
November1st to 15thDay
43%411%26%12%1
1823
16th to endDay
46%5%18%22%6%
1680
December1st to 15thDay
59%5%12%15%6%1
1680
16th to endDay
64%410%13%6%
1792
January1st to 15thNight
49%414%18%12%
2926
16th to endNight
53%5%14%17%8%
2941
February1st to 15thNight
52%411%20%9%
2678
16th to endNight
46%412%24%11%1
2270
March1st to 15thNight
43%312%26%13%
2394
16th to endNight
52%5%13%18%9%
2416
April1st to 15thNight
47%49%24%11%2
2097
16th to endNight
47%5%9%21%13%2
2049
May1st to 15thNight
44%7%12%22%12%
1754
16th to endNight
38%7%13%23%15%2
1754
June1st to 15thNight
33%7%15%24%16%2
1680
16th to endNight
30%8%14%25%16%4
1592
July1st to 15thNight
22%7%15%32%17%5%
1480
16th to endNight
23%6%17%31%19%2
1584
August1st to 15thNight
27%5%14%33%16%3
1717
16th to endNight
32%5%12%26%18%5%
2019
September1st to 15thNight
29%5%8%26%26%2
1950
16th to endNight
29%410%32%20%2
2124
October1st to 15thNight
41%38%22%20%2
2340
16th to endNight
40%412%23%16%2
2513
November1st to 15thNight
41%311%23%16%3
2694
16th to endNight
44%413%27%9%
2940
December1st to 15thNight
55%411%19%8%
2940
16th to endNight
59%411%15%7%
3136

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
23%10%31%28%5%1
180
16th to endDay
18%10%38%23%7%1
192
February1st to 15thDay
19%21%35%20%4
180
16th to endDay
29%11%33%15%10%
159
March1st to 15thDay
21%17%41%15%5%
180
16th to endDay
28%7%30%21%10%2
240
April1st to 15thDay
26%12%33%19%8%
390
16th to endDay
27%11%27%19%12%2
407
May1st to 15thDay
26%10%27%24%10%1
618
16th to endDay
18%9%27%24%15%4
677
June1st to 15thDay
12%427%31%20%3
645
16th to endDay
11%5%30%32%15%4
587
July1st to 15thDay
7%122%32%24%12%
550
16th to endDay
9%121%36%25%6%
595
August1st to 15thDay
9%220%32%26%7%
549
16th to endDay
13%320%30%24%8%
445
September1st to 15thDay
12%220%28%26%9%
375
16th to endDay
13%6%27%29%19%3
283
October1st to 15thDay
29%9%30%18%8%3
180
16th to endDay
19%7%42%23%7%
192
November1st to 15thDay
14%10%30%30%10%3
180
16th to endDay
31%10%28%22%6%
180
December1st to 15thDay
21%14%36%16%8%2
180
16th to endDay
27%11%38%17%4
192
January1st to 15thNight
16%12%33%28%8%
1050
16th to endNight
17%10%35%30%5%
1120
February1st to 15thNight
20%11%35%25%7%
1030
16th to endNight
19%10%35%28%5%1
800
March1st to 15thNight
20%8%34%25%9%
714
16th to endNight
21%7%34%25%8%1
672
April1st to 15thNight
22%10%37%24%5%
629
16th to endNight
21%7%31%28%9%
624
May1st to 15thNight
19%7%30%32%9%
630
16th to endNight
15%5%30%31%15%1
659
June1st to 15thNight
12%325%41%15%1
630
16th to endNight
11%129%39%17%
597
July1st to 15thNight
6%14%45%30%2
555
16th to endNight
5%17%45%28%3
612
August1st to 15thNight
7%13%45%30%2
575
16th to endNight
12%116%37%28%4
621
September1st to 15thNight
13%215%38%25%5%
585
16th to endNight
9%426%33%24%1
668
October1st to 15thNight
20%7%28%28%13%1
780
16th to endNight
18%10%30%29%10%
832
November1st to 15thNight
16%10%35%27%10%
848
16th to endNight
20%9%38%22%7%
1050
December1st to 15thNight
22%11%35%24%5%
1050
16th to endNight
26%8%31%27%5%
1120
Page generated at 2019-06-20 07:02:32. Version ac04

Copyright 2019 A. Danko


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