Black Creek Pond
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Black Creek Pond clear sky chart from 2005-11-05 to 2017-09-20.

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
27%
14689
13%
46894
7%
14660
34%
14660
16%
33449

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
13%
720
6%
2506
2%
716
18%
716
7%
2027
January16th to endNight
17%
768
11%
2607
5%
768
25%
768
10%
1983
February1st to 15thNight
14%
701
9%
2287
3%
701
22%
701
10%
1748
February16th to endNight
18%
631
14%
1969
5%
631
29%
631
13%
1433
March1st to 15thNight
17%
720
12%
2070
6%
720
24%
720
14%
1534
March16th to endNight
28%
768
20%
2055
8%
768
37%
768
21%
1408
April1st to 15thNight
20%
718
15%
1796
5%
718
26%
718
18%
1320
April16th to endNight
28%
651
17%
1731
8%
651
34%
651
21%
1216
May1st to 15thNight
30%
360
18%
1440
13%
360
42%
360
16%
936
May16th to endNight
31%
375
14%
1497
9%
374
45%
374
19%
935
June1st to 15thNight
33%
360
9%
1440
8%
360
42%
360
14%
962
June16th to endNight
40%
360
8%
1440
9%
360
47%
360
17%
944
July1st to 15thNight
47%
340
14%
1360
20%
340
53%
340
27%
754
July16th to endNight
55%
376
14%
1418
15%
354
60%
354
27%
810
August1st to 15thNight
49%
482
14%
1553
10%
480
54%
480
24%
981
August16th to endNight
48%
690
20%
1836
10%
690
55%
690
36%
1142
September1st to 15thNight
42%
720
16%
1800
7%
720
46%
720
30%
1234
September16th to endNight
46%
677
21%
1854
14%
677
51%
677
30%
1193
October1st to 15thNight
30%
660
16%
1980
10%
660
39%
660
18%
1385
October16th to endNight
20%
704
10%
2175
4%
704
28%
704
12%
1676
November1st to 15thNight
25%
700
17%
2352
12%
700
34%
700
15%
1672
November16th to endNight
19%
720
11%
2520
6%
720
26%
720
9%
1936
December1st to 15thNight
14%
720
6%
2520
2%
720
19%
720
7%
2032
December16th to endNight
11%
768
9%
2688
4%
768
17%
768
7%
2188

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
17%9%36%6%34446%32%
47954
Night
16%9%46%5%34446%33%
47064
Cloud CoverDay
17%9%36%5%34446%32%
47964
Night
16%9%46%5%34446%33%
47069
TransparencyDay
52%6%11%18%10%1
47642
Night
51%6%12%19%9%
46894
SeeingDay
22%14%30%20%8%3
5455
Night
22%14%30%22%8%
14692

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
18%16%6%8%6%3334421%
1432
16th to endDay
14%15%5%10%8%45%44422%
1614
February1st to 15thDay
13%14%5%11%8%45%435%23%
1575
16th to endDay
17%14%47%6%4444326%
1503
March1st to 15thDay
16%12%5%9%8%35%33426%
1877
16th to endDay
13%9%46%5%24345%39%
2169
April1st to 15thDay
22%11%34433345%33%
2152
16th to endDay
21%8%35%42343437%
2240
May1st to 15thDay
19%9%36%5%2335%5%34%
2511
16th to endDay
16%6%35%6%3445%6%35%
2618
June1st to 15thDay
22%6%45%5%3445%7%30%
2520
16th to endDay
16%5%26%5%46%5%5%7%32%
2520
July1st to 15thDay
12%5%35%5%35%5%6%9%36%
2520
16th to endDay
12%5%25%6%36%6%7%9%34%
2654
August1st to 15thDay
12%7%27%6%35%5%6%7%35%
2396
16th to endDay
14%5%25%6%35%5%6%8%37%
2353
September1st to 15thDay
16%5%25%5%34447%41%
2160
16th to endDay
15%6%15%42335%6%43%
1873
October1st to 15thDay
22%8%35%5%34346%31%
1650
16th to endDay
26%9%47%6%35%44423%
1697
November1st to 15thDay
15%9%37%6%35%447%33%
1504
16th to endDay
21%13%6%8%434435%23%
1440
December1st to 15thDay
20%16%6%10%7%3334418%
1440
16th to endDay
22%16%6%7%5%33445%20%
1536
January1st to 15thNight
18%12%6%10%9%36%44418%
2506
16th to endNight
13%14%6%8%7%35%445%26%
2607
February1st to 15thNight
13%14%6%10%7%3445%5%23%
2285
16th to endNight
14%11%5%7%7%3445%5%30%
1969
March1st to 15thNight
16%12%48%6%24245%30%
2058
16th to endNight
14%8%35%5%24445%40%
2055
April1st to 15thNight
20%9%45%5%24335%34%
1796
16th to endNight
17%8%25%6%23446%37%
1731
May1st to 15thNight
20%8%35%42435%5%38%
1440
16th to endNight
15%6%35%435%5%5%8%38%
1495
June1st to 15thNight
17%7%36%5%245%5%6%35%
1440
16th to endNight
14%6%35%435%5%5%8%37%
1440
July1st to 15thNight
9%325%5%35%5%48%47%
1440
16th to endNight
9%3145%25%5%6%9%45%
1514
August1st to 15thNight
8%425%5%446%6%8%42%
1563
16th to endNight
10%414423448%50%
1836
September1st to 15thNight
16%5%25%42435%5%44%
1800
16th to endNight
15%5%2432335%5%48%
1854
October1st to 15thNight
21%7%25%434446%34%
1980
16th to endNight
23%11%37%6%23346%25%
2175
November1st to 15thNight
16%10%36%5%35%445%33%
2352
16th to endNight
22%13%37%6%3445%5%24%
2520
December1st to 15thNight
20%15%5%8%6%25%445%20%
2520
16th to endNight
23%14%6%9%5%34335%19%
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
19%16%6%8%6%25%335%22%
1432
16th to endDay
14%15%6%9%8%4444422%
1614
February1st to 15thDay
13%15%6%10%8%35%436%22%
1575
16th to endDay
17%15%47%7%4343427%
1503
March1st to 15thDay
16%13%5%9%7%46%32426%
1888
16th to endDay
14%8%36%5%24335%40%
2168
April1st to 15thDay
22%11%3442334433%
2152
16th to endDay
21%8%35%424335%37%
2240
May1st to 15thDay
19%8%46%5%24346%33%
2511
16th to endDay
16%6%35%6%35%45%7%35%
2618
June1st to 15thDay
22%7%36%425%45%7%30%
2520
16th to endDay
16%5%26%5%46%6%5%7%32%
2520
July1st to 15thDay
12%5%25%5%35%5%7%8%36%
2520
16th to endDay
12%435%5%45%6%7%9%35%
2654
August1st to 15thDay
12%5%36%7%445%6%7%36%
2396
16th to endDay
12%6%245%35%5%6%9%38%
2353
September1st to 15thDay
17%4245%34448%41%
2160
16th to endDay
16%5%25%5%34346%43%
1873
October1st to 15thDay
22%7%35%5%34446%32%
1650
16th to endDay
26%10%37%6%3444424%
1697
November1st to 15thDay
15%9%36%6%3445%6%34%
1504
16th to endDay
21%12%5%9%5%24346%23%
1440
December1st to 15thDay
21%15%6%9%6%3434419%
1440
16th to endDay
23%16%6%6%424435%20%
1536
January1st to 15thNight
18%14%6%10%8%35%445%19%
2506
16th to endNight
13%13%6%8%7%34445%26%
2607
February1st to 15thNight
13%13%6%11%7%35%45%5%23%
2278
16th to endNight
14%11%5%7%7%3435%6%30%
1969
March1st to 15thNight
17%11%5%7%5%25%345%31%
2070
16th to endNight
15%7%45%5%2344441%
2055
April1st to 15thNight
21%8%45%43434435%
1796
16th to endNight
17%8%35%5%24346%37%
1731
May1st to 15thNight
20%6%35%323346%38%
1440
16th to endNight
14%6%25%4245%5%8%39%
1495
June1st to 15thNight
17%7%35%6%35%45%6%35%
1440
16th to endNight
14%6%34435%5%6%7%36%
1440
July1st to 15thNight
9%424435%5%47%47%
1440
16th to endNight
9%2245%35%5%6%8%46%
1514
August1st to 15thNight
8%5%25%6%346%6%8%42%
1563
16th to endNight
9%42442345%7%51%
1836
September1st to 15thNight
15%5%245%3335%6%45%
1800
16th to endNight
16%6%1432235%5%48%
1854
October1st to 15thNight
21%7%25%42445%6%35%
1980
16th to endNight
24%10%37%5%23347%25%
2175
November1st to 15thNight
16%10%36%5%35%445%33%
2352
16th to endNight
22%12%47%6%34446%24%
2520
December1st to 15thNight
20%15%48%6%2435%6%20%
2520
16th to endNight
23%14%49%6%2433420%
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
64%6%9%11%6%1
1433
16th to endDay
65%5%8%11%8%1
1614
February1st to 15thDay
64%6%10%14%4
1577
16th to endDay
60%6%9%11%10%1
1503
March1st to 15thDay
62%411%13%7%1
1888
16th to endDay
46%5%8%19%14%5%
2169
April1st to 15thDay
54%47%17%13%2
2152
16th to endDay
49%48%18%15%3
2240
May1st to 15thDay
50%5%9%16%14%2
2511
16th to endDay
47%6%12%19%12%1
2622
June1st to 15thDay
53%6%10%19%9%
2520
16th to endDay
48%8%12%19%11%1
2520
July1st to 15thDay
39%7%15%25%10%
2371
16th to endDay
43%9%15%21%9%
2487
August1st to 15thDay
45%9%13%21%9%
2382
16th to endDay
41%7%16%24%9%
2353
September1st to 15thDay
41%6%13%25%11%
2160
16th to endDay
41%7%11%29%10%
1873
October1st to 15thDay
53%5%10%19%9%
1650
16th to endDay
63%6%10%14%4
1697
November1st to 15thDay
50%6%14%18%9%
1504
16th to endDay
62%6%9%12%6%1
1440
December1st to 15thDay
68%6%11%10%2
1440
16th to endDay
65%6%12%9%5%
1536
January1st to 15thNight
66%7%10%10%4
2506
16th to endNight
59%6%9%15%8%
2607
February1st to 15thNight
61%413%14%4
2287
16th to endNight
54%5%11%18%10%
1969
March1st to 15thNight
56%412%19%6%
2070
16th to endNight
45%5%10%20%15%3
2055
April1st to 15thNight
51%48%18%14%1
1796
16th to endNight
47%5%8%19%17%2
1731
May1st to 15thNight
48%5%8%19%15%3
1440
16th to endNight
41%8%13%19%14%2
1497
June1st to 15thNight
48%6%13%19%10%1
1440
16th to endNight
43%10%12%19%13%
1440
July1st to 15thNight
32%7%13%29%15%1
1360
16th to endNight
33%7%17%25%14%
1418
August1st to 15thNight
36%10%17%22%12%
1553
16th to endNight
32%6%16%31%12%
1836
September1st to 15thNight
40%6%12%27%11%1
1800
16th to endNight
37%6%12%33%9%
1854
October1st to 15thNight
49%6%11%20%12%
1980
16th to endNight
59%6%13%14%6%
2175
November1st to 15thNight
51%7%12%16%11%
2352
16th to endNight
61%6%11%16%3
2520
December1st to 15thNight
65%6%13%11%3
2520
16th to endNight
67%6%8%11%5%
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
33%26%15%20%5%
60
16th to endDay
37%18%32%7%3
77
February1st to 15thDay
32%27%34%41
90
16th to endDay
30%24%29%12%3
162
March1st to 15thDay
27%17%33%18%4
270
16th to endDay
23%20%30%16%7%1
288
April1st to 15thDay
28%24%26%12%7%
270
16th to endDay
27%18%25%14%10%3
270
May1st to 15thDay
28%14%27%18%6%4
288
16th to endDay
22%15%34%17%8%2
331
June1st to 15thDay
26%11%29%22%8%1
315
16th to endDay
16%14%33%21%12%1
315
July1st to 15thDay
14%7%30%31%11%4
305
16th to endDay
14%7%33%26%12%5%
326
August1st to 15thDay
13%5%32%30%9%7%
313
16th to endDay
15%7%25%28%13%9%
332
September1st to 15thDay
16%11%25%20%13%12%
315
16th to endDay
17%8%30%20%14%9%
270
October1st to 15thDay
25%15%26%22%7%2
255
16th to endDay
29%17%32%15%3
261
November1st to 15thDay
20%12%34%22%8%1
158
16th to endDay
38%10%31%13%6%
60
December1st to 15thDay
21%26%36%11%3
60
16th to endDay
40%31%26%1
64
January1st to 15thNight
25%20%34%15%4
720
16th to endNight
20%17%36%20%4
768
February1st to 15thNight
20%21%36%17%2
704
16th to endNight
22%20%35%17%4
631
March1st to 15thNight
27%17%33%19%2
720
16th to endNight
19%18%28%23%8%
768
April1st to 15thNight
27%18%30%19%4
718
16th to endNight
23%17%28%22%7%
651
May1st to 15thNight
22%11%29%26%8%1
360
16th to endNight
15%8%39%24%11%
375
June1st to 15thNight
18%11%31%29%8%
360
16th to endNight
19%6%30%30%12%
360
July1st to 15thNight
8%5%32%36%15%
340
16th to endNight
9%129%44%14%1
376
August1st to 15thNight
12%425%36%19%1
482
16th to endNight
10%431%31%20%1
690
September1st to 15thNight
18%6%28%25%18%2
720
16th to endNight
17%9%23%26%21%2
677
October1st to 15thNight
26%12%26%22%11%1
660
16th to endNight
28%16%27%19%6%
704
November1st to 15thNight
22%14%32%20%8%1
700
16th to endNight
32%17%26%16%6%
720
December1st to 15thNight
28%20%31%16%2
720
16th to endNight
34%14%32%16%1
768
Page generated at 2017-09-21 07:18:21. Version ac04

Copyright 2017 A. Danko


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