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 2017-09-22.

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%
16035
18%
46924
11%
15989
45%
15989
25%
30723

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
29%
900
13%
2506
5%
895
35%
895
21%
1769
January16th to endNight
23%
960
15%
2521
5%
960
30%
960
18%
1875
February1st to 15thNight
25%
879
14%
2288
3%
876
32%
876
21%
1649
February16th to endNight
32%
687
19%
1949
7%
687
40%
687
23%
1296
March1st to 15thNight
30%
612
19%
2052
12%
612
38%
612
23%
1270
March16th to endNight
27%
576
12%
2070
6%
576
35%
576
15%
1464
April1st to 15thNight
27%
539
16%
1797
11%
539
37%
539
21%
1188
April16th to endNight
34%
540
19%
1775
13%
540
44%
540
21%
1206
May1st to 15thNight
37%
540
17%
1503
10%
540
44%
540
25%
1029
May16th to endNight
42%
563
18%
1497
7%
561
49%
561
29%
997
June1st to 15thNight
51%
540
15%
1440
7%
540
54%
540
33%
920
June16th to endNight
54%
540
18%
1440
9%
540
58%
540
38%
871
July1st to 15thNight
72%
510
18%
1360
11%
510
73%
510
45%
765
July16th to endNight
69%
564
24%
1453
18%
531
71%
531
45%
815
August1st to 15thNight
70%
539
21%
1610
22%
536
73%
536
40%
905
August16th to endNight
65%
573
21%
1863
24%
573
68%
573
33%
1056
September1st to 15thNight
64%
540
26%
1800
27%
540
68%
540
36%
971
September16th to endNight
53%
585
26%
1866
19%
585
61%
585
36%
1041
October1st to 15thNight
42%
660
25%
1980
18%
660
47%
660
30%
1211
October16th to endNight
34%
704
19%
2126
11%
704
43%
704
26%
1363
November1st to 15thNight
34%
724
24%
2300
15%
724
45%
724
28%
1378
November16th to endNight
27%
900
16%
2520
7%
900
34%
900
23%
1695
December1st to 15thNight
21%
900
12%
2520
4%
900
29%
900
16%
1891
December16th to endNight
23%
960
13%
2688
4%
960
31%
960
14%
2098

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%35%5%3445%7%38%
47960
Night
13%7%35%5%24446%42%
47097
Cloud CoverDay
14%7%35%5%3445%7%37%
47969
Night
13%7%35%5%24446%42%
47101
TransparencyDay
45%6%13%22%11%1
47650
Night
42%5%12%23%13%1
46925
SeeingDay
15%6%27%28%17%4
6052
Night
16%7%30%31%12%1
16036

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%7%5%5%6%446%29%
1432
16th to endDay
14%10%8%9%6%35%5%5%6%23%
1701
February1st to 15thDay
12%11%6%8%6%245%36%32%
1575
16th to endDay
13%9%47%5%345%5%6%35%
1524
March1st to 15thDay
15%9%35%5%335%5%7%35%
1907
16th to endDay
19%10%45%434448%30%
2154
April1st to 15thDay
18%9%36%5%2445%7%32%
2151
16th to endDay
25%9%25%6%33345%31%
2184
May1st to 15thDay
20%7%26%5%35%45%5%31%
2447
16th to endDay
15%5%25%5%345%5%8%36%
2617
June1st to 15thDay
14%5%15%4245%5%8%40%
2520
16th to endDay
11%5%245%3446%9%43%
2520
July1st to 15thDay
7%4245%35%46%9%45%
2520
16th to endDay
8%424435%7%7%10%42%
2613
August1st to 15thDay
9%4245%36%5%7%8%43%
2340
16th to endDay
12%5%245%3445%7%44%
2337
September1st to 15thDay
13%325%313347%51%
2160
16th to endDay
11%425%5%245%46%46%
1891
October1st to 15thDay
16%5%24422346%46%
1650
16th to endDay
18%6%245%23446%40%
1744
November1st to 15thDay
13%6%34434336%45%
1557
16th to endDay
18%8%35%5%23346%37%
1440
December1st to 15thDay
18%12%5%9%434435%26%
1440
16th to endDay
19%15%5%9%7%34335%23%
1536
January1st to 15thNight
12%9%5%7%6%25%45%6%35%
2506
16th to endNight
11%11%5%10%7%34436%32%
2521
February1st to 15thNight
11%12%47%6%33445%36%
2285
16th to endNight
12%9%25%5%33345%42%
1949
March1st to 15thNight
15%8%25%5%22325%45%
2040
16th to endNight
17%9%36%7%3445%5%32%
2070
April1st to 15thNight
16%7%36%42435%5%39%
1797
16th to endNight
21%6%35%424345%38%
1775
May1st to 15thNight
16%6%2433445%8%39%
1503
16th to endNight
11%5%35%5%345%5%7%43%
1496
June1st to 15thNight
10%5%243345%6%8%45%
1440
16th to endNight
9%214325%5%7%8%49%
1440
July1st to 15thNight
5%2123245%6%9%56%
1440
16th to endNight
5%3134335%5%10%54%
1552
August1st to 15thNight
5%31432447%9%53%
1620
16th to endNight
10%414424346%53%
1863
September1st to 15thNight
9%31442334458%
1800
16th to endNight
8%3235%24347%54%
1866
October1st to 15thNight
13%5%245%23235%51%
1980
16th to endNight
15%6%25%423345%44%
2126
November1st to 15thNight
12%6%25%423235%49%
2300
16th to endNight
17%8%34323436%40%
2520
December1st to 15thNight
18%11%48%5%34445%29%
2520
16th to endNight
21%12%5%7%6%23345%26%
2688

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%10%5%7%6%47%447%29%
1432
16th to endDay
14%11%6%9%7%35%5%5%6%23%
1701
February1st to 15thDay
12%12%5%7%6%245%45%32%
1575
16th to endDay
13%9%46%5%345%5%6%35%
1524
March1st to 15thDay
15%10%35%5%2345%6%35%
1918
16th to endDay
19%10%45%5%35%448%29%
2152
April1st to 15thDay
18%9%36%5%2445%7%31%
2151
16th to endDay
24%9%25%433345%31%
2184
May1st to 15thDay
19%8%36%5%35%45%6%30%
2447
16th to endDay
15%5%26%5%35%5%5%7%36%
2617
June1st to 15thDay
14%5%25%335%5%5%8%40%
2520
16th to endDay
10%5%245%345%5%9%43%
2520
July1st to 15thDay
7%4245%35%5%6%9%44%
2520
16th to endDay
7%4245%35%6%8%10%42%
2613
August1st to 15thDay
8%5%25%5%25%6%6%9%43%
2340
16th to endDay
12%5%246%2445%8%43%
2337
September1st to 15thDay
12%414323348%51%
2160
16th to endDay
11%5%25%4335%46%46%
1891
October1st to 15thDay
15%5%24423336%46%
1650
16th to endDay
18%6%24433446%40%
1744
November1st to 15thDay
13%6%345%34336%45%
1557
16th to endDay
18%8%35%5%24446%38%
1440
December1st to 15thDay
18%13%49%5%24335%26%
1440
16th to endDay
18%15%5%8%7%34335%22%
1536
January1st to 15thNight
12%9%47%6%35%446%35%
2506
16th to endNight
11%10%5%10%7%34436%31%
2521
February1st to 15thNight
11%12%48%6%24445%36%
2278
16th to endNight
12%9%35%5%34336%41%
1949
March1st to 15thNight
15%7%35%423236%45%
2052
16th to endNight
17%8%47%6%44446%31%
2070
April1st to 15thNight
16%8%35%43445%5%39%
1797
16th to endNight
20%7%26%42435%5%37%
1775
May1st to 15thNight
15%6%2443445%7%39%
1502
16th to endNight
10%5%35%5%345%5%7%43%
1496
June1st to 15thNight
10%5%25%4335%5%8%44%
1440
16th to endNight
8%32333448%8%48%
1440
July1st to 15thNight
5%213315%46%9%55%
1440
16th to endNight
42144245%5%10%53%
1552
August1st to 15thNight
6%31342447%9%52%
1620
16th to endNight
9%423424346%53%
1863
September1st to 15thNight
9%323423345%57%
1800
16th to endNight
7%423424448%53%
1866
October1st to 15thNight
13%5%25%5%13235%50%
1980
16th to endNight
15%7%35%323445%44%
2126
November1st to 15thNight
11%7%245%13346%49%
2300
16th to endNight
16%9%34324346%40%
2520
December1st to 15thNight
17%11%47%5%3445%5%29%
2520
16th to endNight
21%12%48%5%24345%26%
2688

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%6%12%16%10%
1433
16th to endDay
59%5%13%14%6%
1701
February1st to 15thDay
53%5%13%20%6%
1576
16th to endDay
47%6%14%21%8%1
1524
March1st to 15thDay
47%5%15%21%8%
1918
16th to endDay
53%5%13%20%5%
2154
April1st to 15thDay
50%5%11%23%8%
2151
16th to endDay
55%410%18%9%1
2184
May1st to 15thDay
52%5%13%19%8%
2447
16th to endDay
44%8%13%20%12%1
2621
June1st to 15thDay
40%7%13%23%13%1
2520
16th to endDay
37%8%12%24%16%1
2520
July1st to 15thDay
35%7%13%27%13%2
2371
16th to endDay
33%9%17%22%15%2
2449
August1st to 15thDay
35%8%13%27%13%1
2326
16th to endDay
38%6%11%26%14%1
2337
September1st to 15thDay
32%411%29%20%1
2160
16th to endDay
36%5%12%30%12%1
1891
October1st to 15thDay
39%410%24%19%1
1650
16th to endDay
45%5%12%23%12%1
1744
November1st to 15thDay
40%411%27%14%1
1557
16th to endDay
46%5%18%22%6%
1440
December1st to 15thDay
60%5%11%15%5%
1440
16th to endDay
65%410%11%7%
1536
January1st to 15thNight
48%5%15%18%11%
2506
16th to endNight
53%5%14%17%8%
2521
February1st to 15thNight
50%412%22%9%
2288
16th to endNight
44%413%25%11%1
1949
March1st to 15thNight
42%313%26%12%1
2052
16th to endNight
53%6%13%18%8%
2070
April1st to 15thNight
46%49%25%12%2
1797
16th to endNight
48%49%21%13%2
1775
May1st to 15thNight
42%7%13%23%13%
1503
16th to endNight
38%7%12%22%16%2
1498
June1st to 15thNight
35%6%15%24%15%2
1440
16th to endNight
29%7%13%26%18%4
1440
July1st to 15thNight
23%7%16%32%16%4
1360
16th to endNight
24%6%16%30%19%2
1453
August1st to 15thNight
27%5%14%32%16%2
1610
16th to endNight
31%5%11%26%18%5%
1863
September1st to 15thNight
28%5%9%27%27%1
1800
16th to endNight
29%5%11%32%19%1
1866
October1st to 15thNight
37%38%24%22%3
1980
16th to endNight
41%413%23%14%2
2126
November1st to 15thNight
38%311%24%18%3
2300
16th to endNight
45%314%26%9%
2520
December1st to 15thNight
56%411%19%7%
2520
16th to endNight
60%411%14%7%1
2688

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%10%33%26%22
90
16th to endDay
19%7%31%29%9%3
96
February1st to 15thDay
10%23%38%20%7%
90
16th to endDay
20%7%41%13%16%
81
March1st to 15thDay
23%16%40%13%6%
90
16th to endDay
35%7%27%18%8%1
138
April1st to 15thDay
20%14%32%22%10%
270
16th to endDay
29%10%29%17%10%1
294
May1st to 15thDay
23%10%29%25%8%1
468
16th to endDay
16%10%29%26%13%3
517
June1st to 15thDay
13%426%31%20%3
495
16th to endDay
9%5%32%31%15%5%
495
July1st to 15thDay
7%125%33%21%10%
475
16th to endDay
9%120%36%26%5%
515
August1st to 15thDay
8%320%34%26%7%
493
16th to endDay
11%318%32%25%8%
377
September1st to 15thDay
11%221%28%26%9%
315
16th to endDay
12%5%29%28%20%3
201
October1st to 15thDay
14%7%30%23%16%7%
90
16th to endDay
21%7%38%25%7%
96
November1st to 15thDay
5%8%28%35%14%6%
90
16th to endDay
41%13%28%12%4
90
December1st to 15thDay
26%15%34%16%6%
90
16th to endDay
29%14%39%15%1
96
January1st to 15thNight
16%12%33%28%8%
900
16th to endNight
17%11%36%30%5%
960
February1st to 15thNight
17%11%36%26%8%
880
16th to endNight
17%10%36%29%6%1
687
March1st to 15thNight
20%8%33%26%10%
612
16th to endNight
22%8%34%25%8%1
576
April1st to 15thNight
20%9%38%25%5%
539
16th to endNight
23%6%31%28%8%
540
May1st to 15thNight
19%8%30%32%8%
540
16th to endNight
14%432%32%14%1
563
June1st to 15thNight
13%325%41%14%
540
16th to endNight
9%130%41%16%
540
July1st to 15thNight
7%15%46%28%2
510
16th to endNight
417%45%27%3
564
August1st to 15thNight
7%14%46%29%2
539
16th to endNight
11%115%39%28%4
573
September1st to 15thNight
12%215%38%25%5%
540
16th to endNight
8%427%32%24%2
585
October1st to 15thNight
17%6%28%29%16%1
660
16th to endNight
18%9%31%29%10%
704
November1st to 15thNight
15%10%35%27%10%
724
16th to endNight
21%9%37%22%8%
900
December1st to 15thNight
24%11%36%23%5%
900
16th to endNight
27%8%30%27%5%
960
Page generated at 2017-09-23 05:43:35. Version ac04

Copyright 2017 A. Danko


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