Quyon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Quyon clear sky chart from 2005-11-05 to 2017-08-12.

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
27%
14508
12%
46501
7%
14476
33%
14476
16%
33415

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
15%
720
5%
2506
3%
716
19%
716
7%
2055
January16th to endNight
19%
768
9%
2631
5%
768
26%
768
11%
1980
February1st to 15thNight
17%
704
9%
2287
4%
701
24%
701
11%
1749
February16th to endNight
19%
631
11%
1963
5%
631
28%
631
12%
1473
March1st to 15thNight
18%
720
12%
2085
6%
720
24%
720
14%
1582
March16th to endNight
23%
768
16%
2044
7%
768
30%
768
21%
1409
April1st to 15thNight
21%
718
15%
1796
5%
718
27%
718
18%
1336
April16th to endNight
29%
638
17%
1718
8%
638
35%
638
20%
1219
May1st to 15thNight
29%
360
15%
1440
14%
360
37%
360
16%
946
May16th to endNight
30%
375
12%
1497
10%
374
41%
374
18%
969
June1st to 15thNight
35%
360
9%
1440
7%
360
45%
360
15%
954
June16th to endNight
45%
360
8%
1440
12%
360
49%
360
18%
913
July1st to 15thNight
52%
340
14%
1360
19%
340
58%
340
26%
766
July16th to endNight
55%
376
14%
1418
17%
354
59%
354
26%
797
August1st to 15thNight
44%
443
13%
1492
11%
441
49%
441
25%
926
August16th to endNight
42%
638
15%
1688
8%
638
46%
638
35%
1063
September1st to 15thNight
42%
660
14%
1650
7%
660
45%
660
28%
1153
September16th to endNight
44%
657
20%
1798
13%
657
49%
657
31%
1159
October1st to 15thNight
30%
660
17%
1980
11%
660
39%
660
18%
1400
October16th to endNight
23%
704
10%
2191
6%
704
29%
704
12%
1693
November1st to 15thNight
24%
700
14%
2349
11%
700
31%
700
15%
1681
November16th to endNight
18%
720
8%
2520
6%
720
23%
720
9%
1974
December1st to 15thNight
17%
720
6%
2520
3%
720
21%
720
7%
2039
December16th to endNight
12%
768
8%
2688
3%
768
19%
768
8%
2179

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%8%36%5%3445%6%32%
47479
Night
17%10%46%6%34446%32%
46670
Cloud CoverDay
27%7%35%423345%31%
47488
Night
26%8%35%423335%32%
46676
TransparencyDay
51%6%11%18%9%1
47166
Night
52%5%11%19%9%
46501
SeeingDay
24%11%29%20%10%3
5300
Night
23%11%28%25%9%
14508

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
21%14%7%8%6%4434421%
1432
16th to endDay
15%15%5%8%7%445%46%22%
1593
February1st to 15thDay
12%12%6%12%6%45%5%35%23%
1575
16th to endDay
17%11%6%7%6%34445%26%
1509
March1st to 15thDay
17%11%38%7%45%44427%
1862
16th to endDay
15%7%35%5%24446%40%
2179
April1st to 15thDay
22%9%36%423335%34%
2152
16th to endDay
20%8%36%43334436%
2252
May1st to 15thDay
19%7%46%6%24346%34%
2511
16th to endDay
16%6%35%6%35%45%6%35%
2618
June1st to 15thDay
20%7%35%5%35%45%7%30%
2520
16th to endDay
16%6%246%46%6%6%7%32%
2520
July1st to 15thDay
12%5%25%5%35%6%7%9%37%
2520
16th to endDay
10%5%25%6%345%7%9%37%
2654
August1st to 15thDay
10%6%27%6%45%5%6%7%37%
2369
16th to endDay
11%5%25%5%345%7%9%39%
2151
September1st to 15thDay
16%6%35%5%25%45%8%38%
1980
16th to endDay
14%5%25%424447%44%
1829
October1st to 15thDay
22%6%35%5%2435%6%33%
1650
16th to endDay
27%9%36%5%43435%25%
1680
November1st to 15thDay
15%8%46%6%345%5%6%32%
1507
16th to endDay
24%12%47%6%34345%22%
1440
December1st to 15thDay
20%16%5%9%7%35%446%15%
1440
16th to endDay
23%17%5%10%5%3333419%
1536
January1st to 15thNight
18%16%5%10%8%44435%17%
2506
16th to endNight
13%17%6%8%6%34335%26%
2631
February1st to 15thNight
12%13%6%11%8%3445%5%23%
2285
16th to endNight
16%11%5%7%7%345%45%27%
1963
March1st to 15thNight
18%12%5%7%7%3423429%
2072
16th to endNight
14%7%46%5%33345%41%
2044
April1st to 15thNight
22%9%345%33345%34%
1796
16th to endNight
18%8%36%5%24345%37%
1718
May1st to 15thNight
21%8%34424336%37%
1440
16th to endNight
15%6%26%5%25%448%37%
1495
June1st to 15thNight
17%6%25%5%35%5%6%8%33%
1440
16th to endNight
15%5%25%425%5%7%7%37%
1440
July1st to 15thNight
10%4245%245%5%10%46%
1440
16th to endNight
10%413435%46%9%45%
1514
August1st to 15thNight
9%5%25%5%245%5%10%41%
1502
16th to endNight
9%4244345%5%7%49%
1688
September1st to 15thNight
14%6%35%5%34346%41%
1650
16th to endNight
16%5%35%313235%48%
1798
October1st to 15thNight
19%8%35%5%34445%36%
1980
16th to endNight
24%9%37%6%34345%26%
2191
November1st to 15thNight
19%9%36%6%34445%31%
2349
16th to endNight
24%12%47%6%34435%22%
2520
December1st to 15thNight
22%15%5%8%5%35%435%18%
2520
16th to endNight
24%15%5%9%6%3433419%
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
23%13%6%7%6%3443322%
1432
16th to endDay
17%14%49%7%44445%23%
1593
February1st to 15thDay
19%12%5%12%6%35%43323%
1575
16th to endDay
24%10%6%7%6%2343424%
1509
March1st to 15thDay
34%6%245%2332330%
1872
16th to endDay
33%5%2331223338%
2178
April1st to 15thDay
31%7%2431223434%
2152
16th to endDay
28%7%2432334435%
2252
May1st to 15thDay
39%6%2431222329%
2511
16th to endDay
36%4235%2333432%
2618
June1st to 15thDay
33%5%24434335%29%
2520
16th to endDay
29%414435%445%32%
2520
July1st to 15thDay
12%425%5%35%5%7%9%38%
2520
16th to endDay
10%5%25%5%445%7%9%37%
2654
August1st to 15thDay
35%3135%23345%29%
2369
16th to endDay
37%313212345%33%
2151
September1st to 15thDay
20%5%25%424347%39%
1980
16th to endDay
18%5%25%323346%43%
1829
October1st to 15thDay
25%5%35%424346%33%
1650
16th to endDay
30%8%36%5%33335%27%
1680
November1st to 15thDay
26%7%25%5%2333434%
1507
16th to endDay
31%9%36%42332425%
1440
December1st to 15thDay
26%14%5%8%7%24445%16%
1440
16th to endDay
28%15%48%5%2333420%
1536
January1st to 15thNight
22%15%49%7%3443419%
2506
16th to endNight
17%16%6%7%6%34335%26%
2631
February1st to 15thNight
22%12%5%10%6%3444422%
2278
16th to endNight
26%10%47%7%2444424%
1963
March1st to 15thNight
37%6%345%2312230%
2085
16th to endNight
33%41431222339%
2044
April1st to 15thNight
29%7%2343233435%
1796
16th to endNight
23%7%25%42333438%
1718
May1st to 15thNight
35%6%3331222334%
1440
16th to endNight
30%423322336%35%
1495
June1st to 15thNight
22%5%25%42335%6%38%
1440
16th to endNight
21%423315%5%5%6%39%
1440
July1st to 15thNight
10%3145%2346%9%47%
1440
16th to endNight
10%3145%3446%8%46%
1514
August1st to 15thNight
29%413322336%39%
1502
16th to endNight
32%31232223442%
1688
September1st to 15thNight
18%5%245%34336%42%
1650
16th to endNight
21%5%24312235%48%
1798
October1st to 15thNight
23%7%25%423435%36%
1980
16th to endNight
27%9%36%434235%28%
2191
November1st to 15thNight
34%7%25%42223329%
2349
16th to endNight
38%8%35%42233423%
2520
December1st to 15thNight
31%12%46%5%2443420%
2520
16th to endNight
32%14%47%5%2323319%
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
67%5%9%12%5%
1433
16th to endDay
62%5%10%13%7%
1593
February1st to 15thDay
62%5%11%15%4
1577
16th to endDay
59%411%13%9%1
1509
March1st to 15thDay
58%5%11%15%7%1
1872
16th to endDay
45%410%19%14%5%
2179
April1st to 15thDay
53%37%18%13%2
2152
16th to endDay
50%46%19%15%3
2252
May1st to 15thDay
51%5%7%19%13%2
2511
16th to endDay
49%6%10%19%11%1
2622
June1st to 15thDay
52%7%11%20%8%
2520
16th to endDay
48%8%13%18%10%
2520
July1st to 15thDay
38%8%15%25%11%
2371
16th to endDay
42%9%16%21%9%
2487
August1st to 15thDay
43%8%16%21%9%
2355
16th to endDay
39%7%17%25%10%
2151
September1st to 15thDay
43%7%14%25%9%
1980
16th to endDay
40%6%12%30%9%
1829
October1st to 15thDay
52%5%13%18%9%
1650
16th to endDay
62%6%12%13%5%
1680
November1st to 15thDay
49%7%14%19%8%
1507
16th to endDay
63%6%12%10%5%1
1440
December1st to 15thDay
70%6%10%10%2
1440
16th to endDay
68%5%10%11%4
1536
January1st to 15thNight
70%49%10%4
2506
16th to endNight
60%410%16%7%
2631
February1st to 15thNight
61%5%11%16%5%
2287
16th to endNight
58%5%10%17%9%
1963
March1st to 15thNight
58%48%19%7%
2085
16th to endNight
46%49%19%15%4
2044
April1st to 15thNight
52%47%18%15%1
1796
16th to endNight
49%46%18%17%3
1718
May1st to 15thNight
49%46%20%14%3
1440
16th to endNight
45%6%11%20%13%2
1497
June1st to 15thNight
46%8%13%21%8%1
1440
16th to endNight
42%8%13%20%14%
1440
July1st to 15thNight
33%8%13%28%15%1
1360
16th to endNight
33%7%17%27%14%
1418
August1st to 15thNight
36%9%17%24%11%
1492
16th to endNight
32%7%16%32%11%
1688
September1st to 15thNight
43%5%12%26%10%
1650
16th to endNight
40%312%34%9%
1798
October1st to 15thNight
49%6%10%22%11%
1980
16th to endNight
59%6%12%15%6%
2191
November1st to 15thNight
52%6%13%17%9%
2349
16th to endNight
62%6%11%14%4
2520
December1st to 15thNight
66%6%12%11%3
2520
16th to endNight
68%49%12%4
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
30%25%23%16%5%
60
16th to endDay
35%13%35%9%5%
73
February1st to 15thDay
35%20%33%11%
90
16th to endDay
38%17%25%16%2
168
March1st to 15thDay
26%15%34%17%5%
270
16th to endDay
22%16%32%17%8%2
288
April1st to 15thDay
31%23%21%15%7%
270
16th to endDay
25%15%30%15%10%1
270
May1st to 15thDay
32%10%27%17%9%3
288
16th to endDay
24%13%32%19%8%2
331
June1st to 15thDay
30%8%30%21%7%1
315
16th to endDay
19%10%32%24%11%1
315
July1st to 15thDay
14%5%33%29%11%5%
305
16th to endDay
14%5%30%27%17%4
326
August1st to 15thDay
14%6%23%32%15%7%
297
16th to endDay
17%5%24%26%17%8%
268
September1st to 15thDay
19%7%24%19%17%11%
255
16th to endDay
18%9%27%20%16%7%
254
October1st to 15thDay
26%10%25%22%12%1
255
16th to endDay
35%15%25%15%7%
257
November1st to 15thDay
22%9%33%22%10%
161
16th to endDay
30%20%30%18%1
60
December1st to 15thDay
30%13%38%16%1
60
16th to endDay
46%12%37%3
64
January1st to 15thNight
29%13%31%20%4
720
16th to endNight
22%14%34%23%5%
768
February1st to 15thNight
19%15%37%22%5%
704
16th to endNight
23%17%31%22%5%
631
March1st to 15thNight
26%14%31%24%2
720
16th to endNight
20%16%30%22%10%
768
April1st to 15thNight
29%15%28%21%5%
718
16th to endNight
23%16%26%25%6%
638
May1st to 15thNight
27%7%25%28%9%1
360
16th to endNight
20%8%33%25%12%
375
June1st to 15thNight
21%6%30%31%9%
360
16th to endNight
18%5%26%35%13%1
360
July1st to 15thNight
11%227%40%18%
340
16th to endNight
10%324%42%16%1
376
August1st to 15thNight
12%422%36%22%1
443
16th to endNight
11%5%24%37%19%1
638
September1st to 15thNight
18%6%26%27%18%2
660
16th to endNight
20%6%24%27%19%2
657
October1st to 15thNight
26%10%26%24%11%
660
16th to endNight
30%13%26%22%6%
704
November1st to 15thNight
25%12%29%21%10%1
700
16th to endNight
32%16%24%18%7%
720
December1st to 15thNight
29%16%29%20%3
720
16th to endNight
35%13%30%15%4
768
Page generated at 2017-08-13 14:16:25. Version ac04

Copyright 2017 A. Danko


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