Kile Knob Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kile Knob Observatory clear sky chart from 2005-11-05 to 2017-04-07.

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
31%
14923
19%
45512
9%
14886
41%
14886
19%
28911

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
14%
716
19%
2327
7%
716
28%
716
11%
1518
January16th to endNight
12%
768
18%
2496
4%
768
30%
768
13%
1586
February1st to 15thNight
15%
702
19%
2287
5%
701
31%
701
13%
1397
February16th to endNight
12%
631
18%
1913
4%
631
28%
631
12%
1281
March1st to 15thNight
18%
720
19%
1980
7%
720
28%
720
16%
1332
March16th to endNight
20%
768
15%
2112
6%
768
27%
768
17%
1432
April1st to 15thNight
20%
686
17%
1765
5%
686
28%
686
19%
1178
April16th to endNight
30%
597
19%
1587
6%
597
39%
597
22%
1018
May1st to 15thNight
32%
495
14%
1485
5%
495
40%
495
18%
1016
May16th to endNight
40%
480
13%
1507
7%
480
47%
480
21%
951
June1st to 15thNight
45%
330
17%
1320
17%
330
53%
330
20%
773
June16th to endNight
46%
336
17%
1326
12%
336
57%
336
23%
737
July1st to 15thNight
50%
465
12%
1395
9%
465
52%
465
24%
894
July16th to endNight
57%
522
14%
1469
10%
489
64%
489
33%
855
August1st to 15thNight
59%
494
19%
1474
14%
491
63%
491
29%
921
August16th to endNight
59%
624
18%
1674
12%
624
62%
624
30%
1087
September1st to 15thNight
54%
660
25%
1685
14%
660
59%
660
32%
1056
September16th to endNight
43%
657
20%
1826
15%
657
48%
657
24%
1200
October1st to 15thNight
42%
660
23%
1980
17%
660
52%
660
24%
1233
October16th to endNight
31%
704
25%
2112
11%
704
48%
704
24%
1253
November1st to 15thNight
32%
700
25%
2140
15%
700
45%
700
24%
1279
November16th to endNight
24%
720
19%
2502
9%
720
38%
720
15%
1572
December1st to 15thNight
19%
720
15%
2520
6%
720
30%
720
10%
1629
December16th to endNight
16%
768
19%
2630
6%
768
33%
768
12%
1713

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%36%6%35%5%5%7%34%
45693
Night
10%5%25%5%35%5%6%8%40%
45705
Cloud CoverDay
12%6%37%6%35%5%5%7%35%
45703
Night
10%5%25%5%35%5%6%8%40%
45709
TransparencyDay
46%5%12%20%12%2
45404
Night
39%5%14%23%13%2
45512
SeeingDay
18%20%20%19%14%6%
4910
Night
15%27%20%23%11%1
14931

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
9%7%49%7%5%6%5%5%6%32%
1611
16th to endDay
9%7%49%5%35%5%5%6%37%
1728
February1st to 15thDay
9%8%47%6%46%5%5%7%35%
1575
16th to endDay
8%9%48%6%3445%7%36%
1557
March1st to 15thDay
11%8%37%5%25%35%7%38%
1969
16th to endDay
13%9%36%6%445%45%33%
2112
April1st to 15thDay
10%6%47%6%3445%7%39%
1997
16th to endDay
15%6%35%4345%46%38%
2051
May1st to 15thDay
19%8%37%6%35%5%5%6%28%
2136
16th to endDay
15%6%37%6%35%5%5%7%33%
2253
June1st to 15thDay
13%5%346%45%6%6%8%33%
2310
16th to endDay
10%6%36%7%46%6%6%8%34%
2299
July1st to 15thDay
14%6%47%6%46%6%6%8%27%
2145
16th to endDay
9%7%37%7%46%6%8%9%28%
2283
August1st to 15thDay
12%7%37%8%5%6%6%7%9%26%
2145
16th to endDay
13%6%37%6%47%7%5%7%29%
2165
September1st to 15thDay
14%6%25%6%45%45%6%38%
1944
16th to endDay
18%6%37%5%3435%6%34%
1803
October1st to 15thDay
18%6%25%5%34346%39%
1650
16th to endDay
13%8%245%2335%6%43%
1760
November1st to 15thDay
10%7%2442445%6%47%
1715
16th to endDay
14%7%36%43435%6%39%
1455
December1st to 15thDay
11%7%36%7%35%5%6%8%35%
1440
16th to endDay
12%7%37%7%46%5%5%6%33%
1590
January1st to 15thNight
8%6%37%8%5%6%5%6%7%35%
2327
16th to endNight
9%7%35%5%46%5%5%7%39%
2496
February1st to 15thNight
8%5%25%6%35%6%6%8%40%
2285
16th to endNight
7%7%37%7%46%6%6%8%34%
1913
March1st to 15thNight
12%6%25%5%36%5%6%8%37%
1968
16th to endNight
12%8%26%5%35%46%7%37%
2112
April1st to 15thNight
9%5%46%5%45%5%49%39%
1765
16th to endNight
12%5%345%3435%8%43%
1587
May1st to 15thNight
13%7%36%7%246%5%7%35%
1485
16th to endNight
12%314435%5%5%11%42%
1505
June1st to 15thNight
9%323436%6%6%11%42%
1320
16th to endNight
6%424435%5%6%10%47%
1326
July1st to 15thNight
9%415%5%35%5%6%9%42%
1485
16th to endNight
5%214435%6%8%10%46%
1577
August1st to 15thNight
8%315%5%35%5%7%9%42%
1485
16th to endNight
9%415%5%35%6%5%9%43%
1674
September1st to 15thNight
10%4144345%6%8%46%
1685
16th to endNight
15%5%24434447%41%
1826
October1st to 15thNight
15%4244345%5%6%43%
1980
16th to endNight
11%3145%245%6%7%44%
2112
November1st to 15thNight
10%7%3442445%6%45%
2140
16th to endNight
12%6%35%5%36%5%46%39%
2502
December1st to 15thNight
10%6%37%8%46%5%6%7%32%
2520
16th to endNight
10%6%36%7%45%5%6%9%33%
2630

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
8%6%48%7%5%6%5%5%6%33%
1611
16th to endDay
8%7%49%6%345%5%6%37%
1728
February1st to 15thDay
8%9%47%6%46%5%5%7%35%
1575
16th to endDay
7%9%49%6%35%36%7%37%
1557
March1st to 15thDay
11%7%37%5%3445%6%39%
1980
16th to endDay
13%9%36%6%346%45%34%
2111
April1st to 15thDay
10%6%47%6%3445%6%40%
1997
16th to endDay
14%6%36%5%345%5%6%39%
2051
May1st to 15thDay
18%7%38%7%35%5%5%6%29%
2136
16th to endDay
13%6%37%7%36%5%6%7%32%
2253
June1st to 15thDay
13%5%35%5%46%6%7%8%33%
2310
16th to endDay
9%5%36%7%47%6%6%8%34%
2299
July1st to 15thDay
13%6%38%7%47%6%6%8%27%
2145
16th to endDay
8%6%38%7%47%6%7%10%28%
2283
August1st to 15thDay
10%6%38%8%5%7%6%7%10%26%
2145
16th to endDay
12%5%36%7%48%7%5%8%29%
2165
September1st to 15thDay
13%6%26%6%45%5%5%6%38%
1944
16th to endDay
18%6%36%6%34446%34%
1803
October1st to 15thDay
18%5%25%444345%39%
1650
16th to endDay
12%8%25%423446%43%
1760
November1st to 15thDay
9%7%3343435%6%47%
1715
16th to endDay
13%7%36%425%35%6%39%
1455
December1st to 15thDay
11%6%36%7%35%5%6%8%36%
1440
16th to endDay
12%7%37%6%45%6%5%6%33%
1590
January1st to 15thNight
8%6%36%8%46%5%6%7%35%
2327
16th to endNight
9%7%35%5%46%5%5%7%39%
2496
February1st to 15thNight
7%6%25%6%35%5%6%8%40%
2278
16th to endNight
7%7%37%7%46%7%6%7%36%
1913
March1st to 15thNight
11%5%25%5%36%5%6%7%38%
1980
16th to endNight
12%8%25%5%35%45%7%38%
2112
April1st to 15thNight
9%5%46%5%35%5%48%40%
1765
16th to endNight
11%5%25%43435%8%43%
1587
May1st to 15thNight
13%7%36%6%245%6%7%35%
1484
16th to endNight
12%32442445%11%43%
1505
June1st to 15thNight
8%223427%6%7%11%42%
1320
16th to endNight
6%3245%345%7%10%47%
1326
July1st to 15thNight
9%424445%5%6%10%42%
1485
16th to endNight
5%314335%6%8%11%46%
1577
August1st to 15thNight
8%325%5%35%6%6%9%42%
1485
16th to endNight
8%425%5%35%5%5%9%42%
1674
September1st to 15thNight
10%3244345%5%7%46%
1685
16th to endNight
15%5%246%2445%6%41%
1826
October1st to 15thNight
15%424435%5%46%44%
1980
16th to endNight
11%4145%25%5%6%7%45%
2112
November1st to 15thNight
9%7%2442445%6%46%
2140
16th to endNight
12%6%35%5%37%5%5%6%39%
2502
December1st to 15thNight
10%6%37%7%45%6%6%8%33%
2520
16th to endNight
10%6%36%6%36%6%6%9%34%
2630

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
48%412%20%11%2
1612
16th to endDay
45%314%20%13%2
1728
February1st to 15thDay
46%5%10%21%14%1
1577
16th to endDay
46%313%23%10%1
1557
March1st to 15thDay
44%5%11%23%13%2
1980
16th to endDay
49%5%10%19%12%2
2112
April1st to 15thDay
42%411%22%15%3
1997
16th to endDay
43%410%21%15%4
2051
May1st to 15thDay
54%413%18%8%
2136
16th to endDay
48%6%15%19%7%2
2257
June1st to 15thDay
43%8%16%20%10%
2310
16th to endDay
44%7%15%18%11%1
2299
July1st to 15thDay
49%8%11%17%11%1
2006
16th to endDay
45%8%13%20%11%1
2128
August1st to 15thDay
51%5%13%19%9%
2132
16th to endDay
49%7%11%21%9%
2165
September1st to 15thDay
43%5%10%19%18%2
1944
16th to endDay
49%37%22%15%1
1803
October1st to 15thDay
44%411%21%13%4
1650
16th to endDay
40%38%27%17%2
1760
November1st to 15thDay
35%39%23%20%6%
1715
16th to endDay
44%211%23%16%2
1455
December1st to 15thDay
44%5%13%19%14%3
1440
16th to endDay
47%5%11%21%11%1
1590
January1st to 15thNight
44%5%12%20%13%4
2327
16th to endNight
43%414%23%12%2
2496
February1st to 15thNight
39%414%27%12%2
2287
16th to endNight
44%6%13%23%10%1
1913
March1st to 15thNight
41%7%12%27%9%2
1980
16th to endNight
42%5%16%21%11%1
2112
April1st to 15thNight
41%414%22%14%2
1765
16th to endNight
37%413%22%17%4
1587
May1st to 15thNight
45%6%17%19%9%
1485
16th to endNight
36%8%21%24%7%1
1507
June1st to 15thNight
33%11%16%27%10%
1320
16th to endNight
30%9%18%27%12%1
1326
July1st to 15thNight
36%9%19%19%12%2
1395
16th to endNight
26%9%22%26%13%1
1469
August1st to 15thNight
34%7%18%24%14%
1474
16th to endNight
37%6%15%28%11%1
1674
September1st to 15thNight
33%5%15%20%21%2
1685
16th to endNight
42%410%25%17%
1826
October1st to 15thNight
40%312%27%14%2
1980
16th to endNight
35%312%26%19%1
2112
November1st to 15thNight
36%310%21%19%8%
2140
16th to endNight
42%411%21%16%2
2502
December1st to 15thNight
45%5%14%20%12%2
2520
16th to endNight
44%5%14%22%10%1
2630

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
28%25%25%11%7%1
90
16th to endDay
40%26%20%11%1
96
February1st to 15thDay
27%37%32%2
90
16th to endDay
24%30%31%14%
135
March1st to 15thDay
24%28%26%14%5%
270
16th to endDay
18%32%22%18%6%2
288
April1st to 15thDay
16%37%19%17%8%1
235
16th to endDay
18%25%19%15%14%6%
210
May1st to 15thDay
23%25%19%13%12%5%
228
16th to endDay
17%19%14%22%15%9%
267
June1st to 15thDay
12%21%20%19%20%5%
255
16th to endDay
10%21%27%24%10%5%
255
July1st to 15thDay
16%12%26%25%12%6%
245
16th to endDay
8%14%15%26%20%14%
270
August1st to 15thDay
10%10%18%23%22%13%
253
16th to endDay
11%8%9%22%25%22%
268
September1st to 15thDay
11%12%11%21%24%18%
255
16th to endDay
25%9%17%21%18%7%
254
October1st to 15thDay
20%14%15%26%19%4
255
16th to endDay
18%21%26%18%13%2
272
November1st to 15thDay
15%22%20%23%16%2
223
16th to endDay
26%23%26%15%41
63
December1st to 15thDay
30%18%26%18%33
60
16th to endDay
34%21%28%13%1
73
January1st to 15thNight
22%37%21%15%3
720
16th to endNight
19%37%27%15%
768
February1st to 15thNight
19%36%26%16%
704
16th to endNight
17%40%26%15%
631
March1st to 15thNight
18%34%25%17%3
720
16th to endNight
17%33%26%17%41
768
April1st to 15thNight
13%38%25%19%3
686
16th to endNight
16%29%19%23%10%1
597
May1st to 15thNight
15%27%18%25%10%2
495
16th to endNight
13%22%17%27%17%2
482
June1st to 15thNight
8%21%20%29%18%1
330
16th to endNight
5%22%19%40%11%1
336
July1st to 15thNight
12%14%16%32%22%1
465
16th to endNight
5%19%11%30%27%6%
522
August1st to 15thNight
9%11%11%39%27%1
494
16th to endNight
9%10%11%32%32%3
624
September1st to 15thNight
8%13%14%28%28%5%
660
16th to endNight
18%13%16%26%23%2
657
October1st to 15thNight
18%18%15%25%18%2
660
16th to endNight
17%24%23%24%9%1
704
November1st to 15thNight
16%26%22%22%11%1
700
16th to endNight
20%32%19%19%6%
720
December1st to 15thNight
17%37%21%19%3
720
16th to endNight
20%34%23%19%1
768
Page generated at 2017-04-08 05:35:14. Version ac04

Copyright 2017 A. Danko


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