Conconully
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Conconully clear sky chart from 2005-11-05 to 2018-11-30.

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
53%
16086
15%
51722
12%
16059
57%
16059
24%
33369

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
37%
777
7%
2716
6%
776
40%
776
11%
2106
January16th to endNight
38%
832
7%
2912
6%
832
40%
832
11%
2292
February1st to 15thNight
43%
759
8%
2552
6%
757
48%
757
14%
1899
February16th to endNight
46%
684
14%
2118
11%
684
52%
684
21%
1450
March1st to 15thNight
48%
780
12%
2337
10%
780
52%
780
21%
1644
March16th to endNight
46%
832
14%
2168
6%
832
51%
832
24%
1534
April1st to 15thNight
50%
779
14%
1949
6%
779
53%
779
26%
1373
April16th to endNight
54%
580
16%
1738
13%
580
57%
580
32%
1022
May1st to 15thNight
56%
389
20%
1559
23%
389
65%
389
30%
810
May16th to endNight
65%
406
11%
1624
17%
406
68%
406
26%
910
June1st to 15thNight
62%
390
8%
1560
9%
390
64%
390
27%
871
June16th to endNight
63%
390
11%
1424
7%
390
66%
390
36%
735
July1st to 15thNight
73%
370
15%
1457
16%
370
78%
370
49%
580
July16th to endNight
80%
408
22%
1544
32%
386
84%
386
56%
578
August1st to 15thNight
84%
384
29%
1528
39%
382
88%
382
55%
577
August16th to endNight
74%
730
31%
1972
23%
730
76%
730
58%
976
September1st to 15thNight
73%
780
30%
1950
16%
780
77%
780
60%
993
September16th to endNight
68%
776
27%
2104
20%
776
71%
776
43%
1203
October1st to 15thNight
57%
780
20%
2340
18%
780
62%
780
33%
1383
October16th to endNight
55%
832
17%
2658
14%
832
61%
832
24%
1726
November1st to 15thNight
46%
820
12%
2774
11%
820
49%
820
18%
1957
November16th to endNight
38%
840
8%
2940
6%
840
42%
840
12%
2233
December1st to 15thNight
42%
904
9%
2854
6%
904
45%
904
14%
2153
December16th to endNight
34%
864
10%
2944
7%
864
38%
864
10%
2364

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
9%8%36%5%35%5%5%6%38%
52580
Night
9%8%36%5%345%5%7%40%
51890
Cloud CoverDay
8%6%25%5%35%5%6%7%41%
52580
Night
8%7%36%5%3445%7%41%
51894
TransparencyDay
38%7%15%22%13%3
52251
Night
40%7%15%21%12%2
51723
SeeingDay
11%12%30%27%14%4
6962
Night
12%419%39%21%2
16096

By Month

Percentage Cloud Cover NW (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
14%13%47%6%345%5%7%26%
1552
16th to endDay
10%14%6%8%5%44447%30%
1664
February1st to 15thDay
9%13%48%6%446%5%7%29%
1640
16th to endDay
8%13%5%9%6%235%6%8%31%
1642
March1st to 15thDay
13%14%47%6%45%5%5%7%26%
1952
16th to endDay
11%12%5%7%7%46%5%7%8%22%
2407
April1st to 15thDay
11%12%5%8%8%46%6%6%7%22%
2329
16th to endDay
8%10%47%7%46%5%6%8%31%
2496
May1st to 15thDay
8%8%46%6%46%6%6%7%34%
2721
16th to endDay
14%7%38%7%46%6%6%7%28%
2839
June1st to 15thDay
14%7%36%6%47%6%46%31%
2730
16th to endDay
10%6%36%6%25%5%6%7%39%
2859
July1st to 15thDay
4314435%46%6%56%
2746
16th to endDay
3313324346%62%
2881
August1st to 15thDay
3314424347%59%
2676
16th to endDay
4415%434446%55%
2580
September1st to 15thDay
4324423346%59%
2340
16th to endDay
9%5%25%5%345%46%47%
2185
October1st to 15thDay
11%6%26%5%345%5%6%42%
1950
16th to endDay
12%9%46%435%45%7%37%
1917
November1st to 15thDay
15%9%47%7%35%45%6%30%
1745
16th to endDay
13%12%47%6%45%5%5%6%27%
1674
December1st to 15thDay
10%10%5%8%7%45%46%5%32%
1417
16th to endDay
15%14%47%6%35%5%5%5%26%
1638
January1st to 15thNight
13%12%49%6%35%45%7%26%
2716
16th to endNight
12%11%5%7%7%345%6%8%28%
2912
February1st to 15thNight
11%11%45%5%35%5%5%7%32%
2540
16th to endNight
8%9%47%5%345%6%8%34%
2118
March1st to 15thNight
11%10%46%6%37%6%6%7%29%
2337
16th to endNight
8%10%38%7%46%6%5%6%31%
2164
April1st to 15thNight
8%9%39%7%46%5%5%6%32%
1949
16th to endNight
6%7%36%6%25%46%7%42%
1738
May1st to 15thNight
6%6%245%35%5%5%6%47%
1559
16th to endNight
12%6%24425%7%7%8%38%
1624
June1st to 15thNight
9%5%35%5%36%5%7%6%41%
1560
16th to endNight
5%4245%3445%7%50%
1424
July1st to 15thNight
22133235%5%465%
1537
16th to endNight
11322335%7%68%
1640
August1st to 15thNight
1113223246%68%
1536
16th to endNight
3213423347%63%
1972
September1st to 15thNight
421331335%6%65%
1950
16th to endNight
7%41442445%7%51%
2104
October1st to 15thNight
11%6%25%42346%5%48%
2340
16th to endNight
13%8%26%6%345%5%6%37%
2658
November1st to 15thNight
15%8%46%5%345%5%7%32%
2774
16th to endNight
13%13%5%8%6%45%6%45%27%
2940
December1st to 15thNight
10%13%5%8%6%3346%7%31%
2854
16th to endNight
12%17%5%7%6%35%445%26%
2944

Percentage Cloud Cover SW (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
11%13%5%7%8%45%45%7%26%
1552
16th to endDay
10%11%6%9%7%5%435%7%27%
1664
February1st to 15thDay
7%11%37%6%46%6%7%8%30%
1640
16th to endDay
7%10%37%6%35%5%7%7%35%
1642
March1st to 15thDay
13%9%25%5%47%6%6%9%29%
1952
16th to endDay
11%9%26%7%46%6%8%9%27%
2407
April1st to 15thDay
10%8%49%7%47%6%7%7%27%
2329
16th to endDay
7%7%36%6%36%6%7%9%36%
2496
May1st to 15thDay
7%5%25%6%35%6%6%9%40%
2721
16th to endDay
11%5%25%6%35%6%7%8%34%
2839
June1st to 15thDay
12%5%36%5%36%6%7%7%35%
2730
16th to endDay
8%5%25%5%35%6%7%7%43%
2859
July1st to 15thDay
331232445%7%60%
2746
16th to endDay
321222335%5%66%
2881
August1st to 15thDay
221232445%8%63%
2676
16th to endDay
3113435%5%46%61%
2580
September1st to 15thDay
221432345%6%62%
2340
16th to endDay
6%4135%345%6%6%50%
2185
October1st to 15thDay
9%4246%3446%7%44%
1950
16th to endDay
11%6%37%5%145%7%7%39%
1917
November1st to 15thDay
14%7%35%7%45%6%6%7%32%
1745
16th to endDay
13%10%46%8%45%5%6%6%28%
1674
December1st to 15thDay
9%9%49%8%46%5%5%5%29%
1417
16th to endDay
13%14%5%8%9%4445%6%23%
1638
January1st to 15thNight
12%12%6%8%7%35%45%7%25%
2716
16th to endNight
11%13%5%9%8%5%5%46%6%25%
2912
February1st to 15thNight
9%11%35%7%45%5%6%7%31%
2540
16th to endNight
8%9%36%6%445%6%9%37%
2118
March1st to 15thNight
11%8%26%7%35%6%7%8%33%
2337
16th to endNight
7%7%36%7%47%7%6%8%34%
2168
April1st to 15thNight
8%6%28%7%46%6%6%5%37%
1949
16th to endNight
5%6%24435%5%6%8%46%
1738
May1st to 15thNight
5%415%5%35%45%9%50%
1559
16th to endNight
10%5%24425%6%7%9%42%
1624
June1st to 15thNight
9%325%6%35%5%7%7%43%
1560
16th to endNight
43235%25%5%5%7%53%
1424
July1st to 15thNight
213223446%68%
1537
16th to endNight
11212245%7%70%
1640
August1st to 15thNight
121212447%70%
1536
16th to endNight
211232345%7%66%
1972
September1st to 15thNight
321221235%6%68%
1950
16th to endNight
6%31432445%7%55%
2104
October1st to 15thNight
10%41442345%7%50%
2340
16th to endNight
12%5%26%5%35%5%6%7%40%
2658
November1st to 15thNight
14%8%35%5%35%46%7%35%
2774
16th to endNight
13%13%5%7%6%45%46%5%27%
2940
December1st to 15thNight
9%12%5%9%7%35%45%6%29%
2854
16th to endNight
12%17%6%9%6%45%34425%
2944

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
58%12%13%12%3
1552
16th to endDay
57%10%13%14%3
1664
February1st to 15thDay
49%12%18%14%5%
1640
16th to endDay
44%11%20%17%6%
1642
March1st to 15thDay
49%9%20%16%4
1952
16th to endDay
47%8%20%17%5%
2407
April1st to 15thDay
49%7%17%17%6%
2329
16th to endDay
39%8%17%23%8%2
2496
May1st to 15thDay
36%6%17%26%11%1
2721
16th to endDay
41%6%19%23%8%
2843
June1st to 15thDay
41%5%15%21%11%4
2730
16th to endDay
34%414%26%17%2
2859
July1st to 15thDay
19%411%25%26%12%
2597
16th to endDay
17%37%25%32%13%
2714
August1st to 15thDay
16%410%31%28%7%
2659
16th to endDay
20%411%31%25%5%
2580
September1st to 15thDay
19%413%28%27%6%
2340
16th to endDay
30%6%17%27%16%2
2185
October1st to 15thDay
34%7%18%25%14%
1950
16th to endDay
42%11%16%21%8%
1917
November1st to 15thDay
48%11%15%14%8%1
1745
16th to endDay
54%10%14%14%4
1674
December1st to 15thDay
54%10%15%16%3
1417
16th to endDay
63%7%11%12%5%
1638
January1st to 15thNight
59%9%14%12%4
2716
16th to endNight
61%8%14%10%4
2912
February1st to 15thNight
50%12%17%13%5%
2552
16th to endNight
41%11%19%21%5%
2118
March1st to 15thNight
45%9%18%21%4
2337
16th to endNight
44%8%17%23%5%
2168
April1st to 15thNight
43%7%16%22%9%1
1949
16th to endNight
32%6%18%28%11%2
1738
May1st to 15thNight
30%5%14%30%16%2
1560
16th to endNight
33%7%21%26%10%
1624
June1st to 15thNight
34%6%14%26%15%4
1560
16th to endNight
26%6%15%30%18%2
1424
July1st to 15thNight
16%39%29%27%13%
1457
16th to endNight
11%49%27%29%17%
1544
August1st to 15thNight
12%411%29%32%9%
1528
16th to endNight
16%311%30%32%5%
1972
September1st to 15thNight
15%313%28%31%7%
1950
16th to endNight
26%5%14%32%15%4
2104
October1st to 15thNight
32%5%16%27%16%1
2340
16th to endNight
40%8%15%28%7%
2658
November1st to 15thNight
46%11%18%14%6%2
2774
16th to endNight
56%9%14%14%5%
2940
December1st to 15thNight
55%9%16%15%3
2854
16th to endNight
63%7%8%12%5%
2944

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
17%6%14%25%24%11%
90
16th to endDay
35%8%22%18%12%2
96
February1st to 15thDay
9%11%34%31%12%
210
16th to endDay
11%11%32%29%13%1
274
March1st to 15thDay
23%17%29%20%6%2
330
16th to endDay
17%22%32%17%8%
352
April1st to 15thDay
21%20%31%18%6%1
329
16th to endDay
11%20%32%18%11%5%
318
May1st to 15thDay
12%16%35%22%10%2
348
16th to endDay
14%9%23%27%18%6%
394
June1st to 15thDay
15%13%30%26%11%2
375
16th to endDay
9%13%33%27%14%2
504
July1st to 15thDay
410%32%33%16%2
381
16th to endDay
39%32%31%18%4
391
August1st to 15thDay
5%6%23%33%20%9%
359
16th to endDay
5%9%27%32%18%7%
396
September1st to 15thDay
412%30%27%18%8%
375
16th to endDay
8%11%33%29%13%4
375
October1st to 15thDay
12%14%33%26%11%2
375
16th to endDay
16%10%23%26%17%6%
237
November1st to 15thDay
18%9%30%32%7%2
149
16th to endDay
20%7%25%24%18%3
118
December1st to 15thDay
12%6%22%31%15%12%
90
16th to endDay
10%328%45%10%2
96
January1st to 15thNight
19%6%22%31%16%3
780
16th to endNight
18%5%20%38%15%
832
February1st to 15thNight
15%324%40%14%2
764
16th to endNight
13%425%34%19%2
684
March1st to 15thNight
15%422%40%15%1
780
16th to endNight
11%5%25%42%15%1
832
April1st to 15thNight
11%420%41%20%1
779
16th to endNight
8%422%44%17%2
580
May1st to 15thNight
6%226%40%22%1
390
16th to endNight
11%212%37%34%2
407
June1st to 15thNight
8%316%43%26%1
390
16th to endNight
5%221%43%26%1
390
July1st to 15thNight
3215%39%37%1
370
16th to endNight
1112%45%36%2
408
August1st to 15thNight
319%34%45%5%
384
16th to endNight
4115%40%34%3
730
September1st to 15thNight
4312%36%34%8%
780
16th to endNight
8%215%39%30%4
776
October1st to 15thNight
13%217%40%23%2
780
16th to endNight
16%218%40%17%3
832
November1st to 15thNight
17%5%21%43%10%
820
16th to endNight
21%7%21%33%14%2
840
December1st to 15thNight
16%5%18%42%15%1
904
16th to endNight
22%6%21%43%6%
864
Page generated at 2018-12-01 08:35:36. Version ac04

Copyright 2018 A. Danko


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