Burk's Falls
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Burk's Falls clear sky chart from 2005-11-05 to 2018-03-21.

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
28%
15657
12%
49079
7%
15624
33%
15624
15%
36017

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
12%
920
6%
2856
2%
916
16%
916
7%
2424
January16th to endNight
19%
832
10%
2733
5%
832
26%
832
10%
2187
February1st to 15thNight
16%
762
9%
2482
3%
761
23%
761
9%
1979
February16th to endNight
19%
683
10%
2214
5%
683
25%
683
10%
1726
March1st to 15thNight
17%
780
11%
2145
4%
780
24%
780
14%
1634
March16th to endNight
30%
792
20%
2178
10%
792
39%
792
23%
1477
April1st to 15thNight
22%
716
14%
1806
5%
716
28%
716
19%
1365
April16th to endNight
32%
540
18%
1620
10%
540
38%
540
21%
1122
May1st to 15thNight
34%
441
16%
1521
13%
441
41%
441
20%
996
May16th to endNight
35%
374
13%
1497
11%
374
46%
374
20%
883
June1st to 15thNight
39%
360
10%
1345
9%
360
46%
360
18%
868
June16th to endNight
42%
360
10%
1260
10%
360
48%
360
21%
802
July1st to 15thNight
51%
340
15%
1190
18%
340
55%
340
30%
664
July16th to endNight
51%
421
13%
1460
13%
396
54%
396
24%
875
August1st to 15thNight
54%
539
14%
1609
11%
536
57%
536
27%
1036
August16th to endNight
50%
609
18%
1755
10%
609
55%
609
31%
1098
September1st to 15thNight
43%
720
16%
1800
8%
720
46%
720
30%
1195
September16th to endNight
45%
717
20%
2009
13%
717
50%
717
30%
1293
October1st to 15thNight
30%
720
16%
2160
11%
720
37%
720
19%
1527
October16th to endNight
18%
768
9%
2306
4%
768
24%
768
10%
1852
November1st to 15thNight
25%
760
14%
2650
11%
760
31%
760
14%
1923
November16th to endNight
19%
780
9%
2730
5%
780
23%
780
9%
2189
December1st to 15thNight
13%
780
6%
2730
2%
780
18%
780
5%
2354
December16th to endNight
11%
943
8%
3023
3%
943
17%
943
7%
2548

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
19%11%47%5%34446%29%
49773
Night
17%12%47%5%24445%29%
49242
Cloud CoverDay
19%11%47%5%34446%29%
49783
Night
17%12%47%5%34445%29%
49247
TransparencyDay
56%410%18%9%
49456
Night
56%411%18%8%
49079
SeeingDay
25%13%29%19%9%3
6273
Night
24%11%28%24%9%1
15661

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
19%18%8%11%5%2334417%
1408
16th to endDay
16%18%8%11%7%34435%17%
1840
February1st to 15thDay
13%18%8%13%8%3434419%
1710
16th to endDay
17%18%6%10%7%2433420%
1542
March1st to 15thDay
16%15%5%7%6%35%435%26%
2132
16th to endDay
13%9%47%6%245%45%37%
2174
April1st to 15thDay
22%12%5%4423336%30%
2152
16th to endDay
21%10%35%323236%37%
2340
May1st to 15thDay
20%8%36%5%3445%6%31%
2430
16th to endDay
17%6%35%5%245%47%38%
2618
June1st to 15thDay
20%8%36%5%25%45%7%29%
2611
16th to endDay
18%6%26%5%36%45%7%32%
2700
July1st to 15thDay
15%5%25%5%45%45%7%38%
2700
16th to endDay
13%7%35%5%35%6%7%9%32%
2606
August1st to 15thDay
15%7%35%7%45%45%7%33%
2340
16th to endDay
16%6%25%6%45%5%5%7%34%
2435
September1st to 15thDay
19%7%26%5%2435%6%35%
2160
16th to endDay
21%7%24433336%38%
1950
October1st to 15thDay
24%10%36%423345%31%
1800
16th to endDay
34%12%46%42333420%
1917
November1st to 15thDay
22%14%5%7%5%24345%23%
1538
16th to endDay
25%18%7%7%6%2423416%
1560
December1st to 15thDay
19%24%7%11%6%2344411%
1560
16th to endDay
18%24%7%10%6%3423414%
1550
January1st to 15thNight
20%18%6%11%7%3434315%
2856
16th to endNight
14%18%7%9%8%24345%20%
2733
February1st to 15thNight
11%17%7%12%8%35%445%18%
2480
16th to endNight
14%17%7%9%8%3433421%
2214
March1st to 15thNight
16%15%6%7%6%3333428%
2133
16th to endNight
14%10%36%5%23335%41%
2178
April1st to 15thNight
22%12%45%423345%31%
1806
16th to endNight
18%9%35%5%24347%35%
1620
May1st to 15thNight
17%8%35%42445%7%35%
1521
16th to endNight
14%6%2442446%8%39%
1495
June1st to 15thNight
15%8%35%435%35%7%36%
1345
16th to endNight
14%6%346%245%6%8%36%
1260
July1st to 15thNight
12%5%25%41345%7%47%
1260
16th to endNight
11%5%24435%6%6%8%42%
1558
August1st to 15thNight
13%5%245%245%5%7%43%
1620
16th to endNight
12%415%5%4345%7%44%
1755
September1st to 15thNight
14%5%2443446%7%42%
1800
16th to endNight
15%6%245%24346%44%
2009
October1st to 15thNight
21%8%36%424446%33%
2160
16th to endNight
28%15%36%5%2433423%
2306
November1st to 15thNight
22%11%35%424346%28%
2650
16th to endNight
25%15%5%8%6%33335%19%
2730
December1st to 15thNight
20%23%8%10%6%3433313%
2730
16th to endNight
20%20%9%10%6%2343315%
3023

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%18%8%11%5%2434417%
1408
16th to endDay
15%18%8%10%7%34435%17%
1840
February1st to 15thDay
13%18%8%13%8%3434418%
1710
16th to endDay
16%19%6%10%7%3434420%
1542
March1st to 15thDay
16%15%5%7%6%34335%26%
2143
16th to endDay
13%9%47%6%24445%37%
2173
April1st to 15thDay
22%12%5%4423336%30%
2152
16th to endDay
21%10%35%313336%37%
2340
May1st to 15thDay
20%9%36%43445%6%31%
2430
16th to endDay
17%6%25%5%25%5%47%38%
2618
June1st to 15thDay
20%8%36%5%35%45%7%29%
2611
16th to endDay
18%6%36%5%35%45%7%32%
2700
July1st to 15thDay
15%5%25%5%45%45%7%38%
2700
16th to endDay
13%6%35%5%35%5%7%9%32%
2606
August1st to 15thDay
15%7%36%7%45%5%47%33%
2340
16th to endDay
16%6%25%5%36%5%5%7%34%
2435
September1st to 15thDay
19%7%26%5%2435%6%35%
2160
16th to endDay
21%6%24433336%38%
1950
October1st to 15thDay
24%11%26%413335%31%
1800
16th to endDay
34%12%46%423335%20%
1917
November1st to 15thDay
22%14%5%6%5%34345%23%
1538
16th to endDay
25%18%7%8%5%2323416%
1560
December1st to 15thDay
19%24%7%11%6%2334411%
1560
16th to endDay
18%24%7%9%6%3433414%
1550
January1st to 15thNight
20%18%6%11%7%3434315%
2856
16th to endNight
14%18%8%10%7%34345%20%
2733
February1st to 15thNight
11%17%7%11%8%35%44419%
2473
16th to endNight
14%17%7%9%7%4433421%
2214
March1st to 15thNight
16%15%5%7%6%3343428%
2145
16th to endNight
14%10%36%5%23435%40%
2178
April1st to 15thNight
22%12%44433345%31%
1806
16th to endNight
18%10%25%5%24347%35%
1620
May1st to 15thNight
18%8%25%4245%48%35%
1521
16th to endNight
14%6%2442446%8%39%
1495
June1st to 15thNight
15%8%35%5%35%45%6%37%
1345
16th to endNight
14%6%35%6%25%46%8%36%
1260
July1st to 15thNight
12%5%15%41345%7%47%
1260
16th to endNight
11%5%24435%6%6%8%42%
1558
August1st to 15thNight
13%5%245%345%5%6%44%
1620
16th to endNight
12%415%5%3345%7%44%
1755
September1st to 15thNight
14%5%2443446%7%42%
1800
16th to endNight
15%6%24423446%44%
2009
October1st to 15thNight
21%8%36%424446%33%
2160
16th to endNight
28%15%46%5%2333422%
2306
November1st to 15thNight
22%11%35%424347%28%
2650
16th to endNight
25%15%5%8%6%33335%19%
2730
December1st to 15thNight
19%23%8%9%6%3433313%
2730
16th to endNight
20%20%9%10%6%2333315%
3023

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
71%38%10%6%
1409
16th to endDay
70%35%11%6%1
1840
February1st to 15thDay
69%27%13%5%
1712
16th to endDay
68%28%13%7%
1542
March1st to 15thDay
60%312%14%7%1
2143
16th to endDay
47%39%19%15%3
2174
April1st to 15thDay
55%39%18%10%1
2152
16th to endDay
49%38%21%14%2
2340
May1st to 15thDay
52%49%18%13%1
2430
16th to endDay
45%5%11%22%12%1
2622
June1st to 15thDay
53%410%21%10%
2611
16th to endDay
49%6%13%19%10%1
2700
July1st to 15thDay
42%5%11%27%11%1
2541
16th to endDay
46%6%11%25%9%
2443
August1st to 15thDay
49%5%13%20%10%
2327
16th to endDay
47%6%13%24%7%
2435
September1st to 15thDay
48%412%24%8%
2160
16th to endDay
48%312%28%7%
1950
October1st to 15thDay
55%410%19%10%
1800
16th to endDay
68%310%11%5%
1917
November1st to 15thDay
62%5%11%14%5%
1538
16th to endDay
72%38%11%21
1560
December1st to 15thDay
75%48%9%1
1560
16th to endDay
74%26%11%4
1550
January1st to 15thNight
73%47%9%5%
2856
16th to endNight
67%37%13%7%
2733
February1st to 15thNight
67%39%13%4
2482
16th to endNight
66%29%15%6%
2214
March1st to 15thNight
59%212%14%8%1
2145
16th to endNight
46%39%21%16%2
2178
April1st to 15thNight
55%37%18%12%1
1806
16th to endNight
49%38%19%16%2
1620
May1st to 15thNight
47%410%20%15%2
1521
16th to endNight
40%5%14%22%15%1
1497
June1st to 15thNight
47%413%21%12%1
1345
16th to endNight
43%5%14%24%11%
1260
July1st to 15thNight
32%5%14%28%16%2
1190
16th to endNight
38%6%15%26%12%
1460
August1st to 15thNight
38%7%16%24%11%1
1609
16th to endNight
37%5%17%29%10%
1755
September1st to 15thNight
39%6%16%27%10%
1800
16th to endNight
40%314%31%8%
2009
October1st to 15thNight
51%410%21%11%
2160
16th to endNight
66%410%13%4
2306
November1st to 15thNight
56%413%18%6%
2650
16th to endNight
68%311%11%3
2730
December1st to 15thNight
76%47%9%2
2730
16th to endNight
74%37%9%5%
3023

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%25%35%11%2
90
16th to endDay
40%15%27%11%4
137
February1st to 15thDay
26%31%37%5%
135
16th to endDay
45%19%26%8%
120
March1st to 15thDay
28%18%31%15%5%
328
16th to endDay
20%18%32%18%8%1
311
April1st to 15thDay
27%15%30%18%5%1
270
16th to endDay
28%12%30%14%8%4
270
May1st to 15thDay
32%6%25%19%11%4
288
16th to endDay
21%16%30%16%10%3
331
June1st to 15thDay
26%14%28%21%7%1
406
16th to endDay
21%12%34%22%8%1
495
July1st to 15thDay
16%10%32%25%12%2
475
16th to endDay
14%10%30%28%11%3
326
August1st to 15thDay
19%5%24%31%11%7%
313
16th to endDay
22%5%24%20%18%7%
332
September1st to 15thDay
20%7%27%20%14%9%
315
16th to endDay
23%6%22%26%16%4
314
October1st to 15thDay
29%11%27%22%5%3
315
16th to endDay
39%15%25%15%3
333
November1st to 15thDay
33%18%34%11%2
93
16th to endDay
41%18%28%10%1
90
December1st to 15thDay
34%18%30%14%2
90
16th to endDay
28%25%34%9%21
96
January1st to 15thNight
30%16%31%16%4
921
16th to endNight
24%12%33%20%6%
832
February1st to 15thNight
20%17%35%21%4
764
16th to endNight
24%18%29%22%4
683
March1st to 15thNight
25%20%30%19%3
780
16th to endNight
20%13%29%26%8%
792
April1st to 15thNight
30%12%30%21%5%
716
16th to endNight
22%12%28%24%11%1
540
May1st to 15thNight
23%7%28%28%11%
441
16th to endNight
17%8%34%31%8%
375
June1st to 15thNight
16%8%28%34%11%
360
16th to endNight
17%6%26%37%11%
360
July1st to 15thNight
14%225%41%16%
340
16th to endNight
13%5%25%35%18%1
421
August1st to 15thNight
16%417%37%21%2
539
16th to endNight
15%423%33%19%3
609
September1st to 15thNight
17%6%27%26%17%4
720
16th to endNight
18%6%24%28%19%2
717
October1st to 15thNight
25%9%29%25%8%1
720
16th to endNight
36%14%26%17%5%
768
November1st to 15thNight
30%13%25%21%8%
760
16th to endNight
35%13%25%20%4
780
December1st to 15thNight
33%16%28%17%4
780
16th to endNight
34%12%30%17%3
943
Page generated at 2018-03-22 11:34:22. Version ac04

Copyright 2018 A. Danko


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