Burris Fork Creek Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Burris Fork Creek Observatory clear sky chart from 2005-11-06 to 2024-01-12.

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%
24413
22%
74704
14%
24354
49%
24354
28%
46380

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 10thNight
24%
950
20%
2544
7%
946
34%
946
24%
1684
January11th to 20thNight
22%
908
22%
2360
7%
908
32%
908
23%
1615
January21st to endNight
24%
990
21%
2574
6%
990
34%
990
24%
1778
February1st to 10thNight
22%
900
16%
2340
5%
900
28%
900
21%
1667
February11th to 20thNight
21%
839
18%
2234
5%
835
29%
835
23%
1502
February21st to endNight
19%
592
22%
1776
6%
592
32%
592
21%
1177
March1st to 10thNight
25%
558
23%
1998
10%
558
39%
558
22%
1201
March11th to 20thNight
31%
540
19%
1980
13%
540
39%
540
17%
1306
March21st to endNight
24%
594
11%
2163
7%
594
31%
594
13%
1509
April1st to 10thNight
34%
540
23%
1800
15%
540
47%
540
28%
1030
April11th to 20thNight
33%
533
22%
1775
16%
533
45%
533
25%
1091
April21st to endNight
30%
540
19%
1800
11%
540
44%
540
22%
1157
May1st to 10thNight
40%
540
18%
1664
12%
540
48%
540
26%
1066
May11th to 20thNight
46%
531
20%
1533
16%
531
52%
531
29%
983
May21st to endNight
49%
584
20%
1552
13%
582
55%
582
31%
1001
June1st to 10thNight
67%
540
21%
1440
16%
540
69%
540
43%
825
June11th to 20thNight
62%
540
26%
1440
17%
540
66%
540
42%
829
June21st to endNight
69%
540
28%
1440
17%
540
74%
540
54%
757
July1st to 10thNight
73%
525
19%
1400
16%
525
73%
525
41%
833
July11th to 20thNight
75%
522
23%
1526
22%
522
78%
522
48%
795
July21st to endNight
67%
591
25%
1673
24%
558
71%
558
40%
925
August1st to 10thNight
72%
537
23%
1601
24%
534
76%
534
42%
873
August11th to 20thNight
72%
534
27%
1665
31%
534
75%
534
40%
896
August21st to endNight
73%
594
28%
1980
33%
594
76%
594
43%
1001
September1st to 10thNight
67%
540
26%
1800
29%
540
69%
540
38%
949
September11th to 20thNight
66%
540
33%
1800
32%
540
71%
540
37%
969
September21st to endNight
59%
629
30%
2059
24%
629
66%
629
38%
1076
October1st to 10thNight
54%
720
28%
2160
21%
720
59%
720
41%
1167
October11th to 20thNight
35%
720
28%
2160
15%
720
46%
720
31%
1270
October21st to endNight
33%
792
25%
2376
13%
792
44%
792
28%
1460
November1st to 10thNight
39%
740
30%
2272
18%
740
52%
740
36%
1262
November11th to 20thNight
32%
783
28%
2493
15%
783
46%
783
28%
1459
November21st to endNight
28%
950
22%
2660
9%
950
40%
950
28%
1712
December1st to 10thNight
26%
950
20%
2660
8%
950
37%
950
24%
1776
December11th to 20thNight
28%
949
20%
3150
9%
948
36%
948
20%
2048
December21st to endNight
23%
1038
12%
4856
6%
1026
34%
1026
11%
3731

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
13%7%35%5%3445%7%43%
74662
Night
12%7%35%5%3445%7%46%
75058
TransparencyDay
41%412%25%16%3
74377
Night
39%411%25%18%3
74863
SeeingDay
17%8%25%27%17%5%
14465
Night
17%8%29%31%14%1
24421

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 10thDay
11%10%46%5%3445%7%41%
1616
11th to 20thDay
14%13%5%7%6%2445%5%36%
1629
21st to endDay
13%11%46%5%35%447%39%
1782
February1st to 10thDay
16%11%5%8%6%3444435%
1620
11th to 20thDay
15%10%445%3445%6%39%
1612
21st to endDay
18%10%46%5%23446%37%
1480
March1st to 10thDay
13%9%5%6%6%33346%41%
1975
11th to 20thDay
19%10%5%6%5%34446%35%
1980
21st to endDay
21%12%47%6%3445%6%29%
2191
April1st to 10thDay
12%7%36%6%35%45%6%44%
2160
11th to 20thDay
18%7%25%5%35%446%41%
2134
21st to endDay
20%8%36%425%45%6%35%
2160
May1st to 10thDay
18%7%36%5%35%5%5%9%35%
2293
11th to 20thDay
16%6%35%5%35%5%5%7%39%
2360
21st to endDay
12%7%36%6%35%6%6%9%36%
2725
June1st to 10thDay
8%4245%36%5%7%9%46%
2520
11th to 20thDay
9%4245%35%6%6%9%47%
2520
21st to endDay
6%3246%445%7%10%51%
2520
July1st to 10thDay
10%326%5%35%5%7%10%43%
2520
11th to 20thDay
4425%5%35%6%6%9%51%
2377
21st to endDay
8%5%25%5%45%6%6%10%43%
2546
August1st to 10thDay
7%5%25%6%36%6%7%11%43%
2328
11th to 20thDay
8%6%25%5%36%6%6%9%44%
2234
21st to endDay
8%5%2443435%9%53%
2376
September1st to 10thDay
11%4245%3445%7%49%
2160
11th to 20thDay
11%5%24423448%52%
2160
21st to endDay
8%425%425%46%7%54%
1877
October1st to 10thDay
11%6%245%34345%53%
1800
11th to 20thDay
15%6%24423235%52%
1800
21st to endDay
19%9%25%323345%46%
1980
November1st to 10thDay
12%6%2432335%6%54%
1804
11th to 20thDay
14%6%25%32435%7%48%
1682
21st to endDay
17%7%35%42335%6%45%
1520
December1st to 10thDay
13%10%36%6%2345%6%44%
1520
11th to 20thDay
13%10%46%5%23446%43%
1918
21st to endDay
18%15%5%10%6%34445%26%
2783
January1st to 10thNight
11%9%46%6%34445%43%
2544
11th to 20thNight
15%8%37%6%3435%6%39%
2360
21st to endNight
12%10%5%6%5%345%5%5%39%
2574
February1st to 10thNight
14%10%5%8%5%3445%6%35%
2340
11th to 20thNight
14%7%47%5%34446%41%
2233
21st to endNight
15%10%46%5%23436%40%
1776
March1st to 10thNight
14%10%34423445%48%
1998
11th to 20thNight
18%8%36%5%345%5%5%38%
1980
21st to endNight
20%10%46%6%35%5%6%7%29%
2163
April1st to 10thNight
11%6%25%424447%50%
1800
11th to 20thNight
14%8%35%5%3335%6%45%
1775
21st to endNight
17%7%345%43446%41%
1800
May1st to 10thNight
15%5%36%5%235%7%8%42%
1664
11th to 20thNight
14%5%25%5%35%5%46%45%
1532
21st to endNight
12%5%35%5%3446%11%42%
1551
June1st to 10thNight
6%314425%6%6%10%52%
1440
11th to 20thNight
6%4245%25%5%7%10%50%
1440
21st to endNight
33123346%6%10%60%
1440
July1st to 10thNight
8%3235%345%6%9%52%
1440
11th to 20thNight
431343446%10%58%
1577
21st to endNight
7%325%5%25%46%8%52%
1772
August1st to 10thNight
6%324435%5%6%9%53%
1611
11th to 20thNight
6%42442346%8%55%
1665
21st to endNight
6%3244245%5%7%59%
1980
September1st to 10thNight
11%423323448%57%
1800
11th to 20thNight
9%5%2333446%7%54%
1800
21st to endNight
8%5%24424447%57%
2059
October1st to 10thNight
8%423423446%59%
2160
11th to 20thNight
13%5%24424446%51%
2160
21st to endNight
17%7%23423345%49%
2376
November1st to 10thNight
11%5%24324445%58%
2272
11th to 20thNight
13%6%35%423346%50%
2493
21st to endNight
16%7%36%323345%47%
2660
December1st to 10thNight
13%11%45%5%2445%6%41%
2660
11th to 20thNight
14%10%46%5%23446%41%
3279
21st to endNight
18%19%5%9%5%3444426%
4884

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 10thDay
43%311%24%18%1
1617
11th to 20thDay
50%49%24%11%
1629
21st to endDay
46%313%25%11%2
1782
February1st to 10thDay
54%310%20%12%1
1620
11th to 20thDay
47%312%21%13%3
1621
21st to endDay
49%39%23%14%3
1480
March1st to 10thDay
46%29%22%16%3
1975
11th to 20thDay
52%310%20%13%2
1980
21st to endDay
57%412%18%7%1
2191
April1st to 10thDay
41%411%25%17%2
2160
11th to 20thDay
46%311%24%14%2
2134
21st to endDay
51%411%21%13%1
2160
May1st to 10thDay
47%6%14%22%11%1
2293
11th to 20thDay
44%5%12%23%14%1
2364
21st to endDay
44%7%14%22%12%1
2725
June1st to 10thDay
33%6%15%30%16%1
2520
11th to 20thDay
32%6%14%28%17%3
2520
21st to endDay
27%6%17%30%16%4
2520
July1st to 10thDay
35%7%13%27%14%4
2451
11th to 20thDay
29%6%15%27%20%3
2305
21st to endDay
35%6%13%32%12%2
2405
August1st to 10thDay
34%6%19%26%13%1
2314
11th to 20thDay
35%6%12%30%15%1
2234
21st to endDay
29%413%25%22%6%
2376
September1st to 10thDay
34%5%11%29%17%5%
2160
11th to 20thDay
31%49%26%27%3
2160
21st to endDay
29%5%9%29%25%4
1877
October1st to 10thDay
34%49%25%25%4
1800
11th to 20thDay
37%36%27%22%5%
1800
21st to endDay
42%38%24%19%4
1980
November1st to 10thDay
32%313%25%22%5%
1804
11th to 20thDay
38%210%23%23%4
1682
21st to endDay
42%48%30%15%2
1520
December1st to 10thDay
42%310%31%12%1
1520
11th to 20thDay
45%212%25%14%2
1915
21st to endDay
61%5%9%16%9%1
2783
January1st to 10thNight
44%311%24%16%2
2544
11th to 20thNight
46%311%26%13%1
2360
21st to endNight
47%312%23%13%1
2574
February1st to 10thNight
50%410%21%13%2
2340
11th to 20thNight
44%411%21%17%3
2234
21st to endNight
47%310%22%15%4
1776
March1st to 10thNight
41%410%24%18%4
1998
11th to 20thNight
48%5%8%23%13%3
1980
21st to endNight
54%5%12%19%8%1
2163
April1st to 10thNight
35%411%27%20%4
1800
11th to 20thNight
41%49%24%16%5%
1775
21st to endNight
45%49%25%17%1
1800
May1st to 10thNight
40%6%13%23%17%1
1664
11th to 20thNight
40%5%13%23%17%2
1533
21st to endNight
38%6%17%24%14%2
1552
June1st to 10thNight
27%5%17%32%16%3
1440
11th to 20thNight
28%5%12%28%22%5%
1440
21st to endNight
19%5%17%32%21%7%
1440
July1st to 10thNight
29%6%14%31%16%4
1400
11th to 20thNight
22%5%15%31%23%4
1526
21st to endNight
27%6%12%37%16%2
1673
August1st to 10thNight
26%5%18%32%16%2
1601
11th to 20thNight
27%5%11%34%21%2
1665
21st to endNight
24%5%13%28%23%7%
1980
September1st to 10thNight
29%311%26%24%6%
1800
11th to 20thNight
30%49%26%26%5%
1800
21st to endNight
28%38%28%28%4
2059
October1st to 10thNight
27%49%27%27%6%
2160
11th to 20thNight
35%37%25%22%7%
2160
21st to endNight
39%38%23%23%4
2376
November1st to 10thNight
30%411%28%21%6%
2272
11th to 20thNight
37%26%26%24%5%
2493
21st to endNight
41%310%26%17%3
2660
December1st to 10thNight
45%411%25%14%1
2660
11th to 20thNight
45%39%28%14%1
3281
21st to endNight
62%49%15%8%2
4884

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 10thDay
24%16%36%19%5%
270
11th to 20thDay
33%13%40%14%
243
21st to endDay
20%17%45%15%4
264
February1st to 10thDay
27%15%43%13%3
240
11th to 20thDay
26%24%32%12%6%
240
21st to endDay
31%17%38%11%3
198
March1st to 10thDay
19%18%49%13%2
240
11th to 20thDay
30%13%33%21%31
240
21st to endDay
36%18%29%12%5%
277
April1st to 10thDay
20%14%34%25%7%1
420
11th to 20thDay
24%14%32%21%8%
412
21st to endDay
27%11%30%23%7%1
420
May1st to 10thDay
21%11%32%24%12%1
556
11th to 20thDay
22%7%25%28%16%3
625
21st to endDay
16%5%28%26%17%8%
679
June1st to 10thDay
9%315%35%28%10%
630
11th to 20thDay
10%320%39%24%5%
630
21st to endDay
7%5%27%36%19%6%
630
July1st to 10thDay
13%18%32%31%15%
621
11th to 20thDay
7%217%37%29%9%
618
21st to endDay
10%112%33%33%10%
684
August1st to 10thDay
10%13%40%28%9%
626
11th to 20thDay
11%214%35%29%8%
548
21st to endDay
10%110%31%34%14%
495
September1st to 10thDay
12%112%33%32%9%
450
11th to 20thDay
8%116%33%29%12%
450
21st to endDay
8%7%25%32%20%7%
275
October1st to 10thDay
16%429%28%18%4
270
11th to 20thDay
20%18%32%23%7%
270
21st to endDay
32%15%30%20%31
297
November1st to 10thDay
19%7%39%22%10%3
270
11th to 20thDay
22%15%28%26%8%1
270
21st to endDay
28%15%26%27%41
270
December1st to 10thDay
17%16%41%16%9%1
270
11th to 20thDay
22%17%37%20%4
270
21st to endDay
26%18%38%16%2
297
January1st to 10thNight
16%16%36%26%5%
950
11th to 20thNight
21%15%36%22%5%
908
21st to endNight
18%13%39%27%3
990
February1st to 10thNight
21%14%38%23%4
900
11th to 20thNight
21%15%37%24%3
839
21st to endNight
25%15%37%20%3
592
March1st to 10thNight
21%14%36%24%4
558
11th to 20thNight
25%9%31%29%6%
540
21st to endNight
26%11%34%23%5%
594
April1st to 10thNight
17%11%33%32%6%
540
11th to 20thNight
20%10%32%29%8%
533
21st to endNight
21%5%39%27%9%
540
May1st to 10thNight
17%5%30%36%11%1
540
11th to 20thNight
16%325%37%16%2
531
21st to endNight
14%324%33%24%2
584
June1st to 10thNight
9%116%42%30%3
540
11th to 20thNight
8%120%45%24%2
540
21st to endNight
5%120%50%21%2
540
July1st to 10thNight
9%9%38%38%6%
525
11th to 20thNight
6%112%42%37%3
522
21st to endNight
8%112%40%35%3
591
August1st to 10thNight
7%111%44%34%3
537
11th to 20thNight
7%110%46%31%4
534
21st to endNight
7%110%35%42%4
594
September1st to 10thNight
13%112%38%30%6%
540
11th to 20thNight
10%113%38%32%6%
540
21st to endNight
10%322%36%26%3
629
October1st to 10thNight
10%427%34%22%3
720
11th to 20thNight
16%10%35%30%10%
720
21st to endNight
22%10%32%28%8%
792
November1st to 10thNight
14%9%34%32%11%
740
11th to 20thNight
18%12%33%29%8%
783
21st to endNight
21%10%37%26%6%
950
December1st to 10thNight
21%12%35%25%7%1
950
11th to 20thNight
22%9%34%29%5%
950
21st to endNight
24%14%33%26%3
1045
Page generated at 2024-01-09 06:14:44. Version ac07

Copyright 2024 Attilla Danko


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