Doogan's Mountain
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Doogan's Mountain clear sky chart from 2005-11-05 to 2017-12-04.

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
47%
15745
21%
47885
15%
15703
54%
15703
25%
30567

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
23%
720
19%
2327
9%
716
35%
716
16%
1594
January16th to endNight
26%
768
21%
2450
11%
768
37%
768
17%
1650
February1st to 15thNight
26%
703
20%
2112
9%
701
37%
701
21%
1399
February16th to endNight
20%
631
21%
1893
8%
631
31%
631
17%
1305
March1st to 15thNight
26%
720
20%
2085
10%
720
35%
720
21%
1428
March16th to endNight
33%
768
18%
2112
11%
768
38%
768
25%
1404
April1st to 15thNight
38%
598
24%
1856
14%
598
51%
598
30%
1084
April16th to endNight
42%
540
24%
1707
16%
540
52%
540
29%
1030
May1st to 15thNight
49%
540
18%
1620
10%
540
55%
540
26%
1045
May16th to endNight
65%
561
18%
1683
14%
561
67%
561
29%
1075
June1st to 15thNight
69%
540
15%
1620
12%
540
71%
540
31%
1021
June16th to endNight
78%
540
16%
1620
14%
540
79%
540
35%
960
July1st to 15thNight
70%
510
14%
1530
12%
510
72%
510
28%
969
July16th to endNight
76%
564
17%
1595
16%
531
77%
531
30%
1010
August1st to 15thNight
76%
539
18%
1642
18%
536
77%
536
28%
1035
August16th to endNight
69%
573
19%
1910
20%
573
71%
573
24%
1220
September1st to 15thNight
63%
681
17%
1941
15%
681
64%
681
27%
1289
September16th to endNight
62%
717
26%
1980
21%
717
65%
717
33%
1220
October1st to 15thNight
56%
720
32%
1980
26%
720
62%
720
37%
1173
October16th to endNight
49%
768
32%
2329
26%
768
59%
768
34%
1326
November1st to 15thNight
48%
760
28%
2471
24%
760
58%
760
31%
1417
November16th to endNight
38%
780
26%
2535
18%
780
50%
780
25%
1530
December1st to 15thNight
34%
736
19%
2391
14%
736
42%
736
19%
1618
December16th to endNight
29%
768
18%
2496
13%
768
36%
768
16%
1765

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%6%25%5%35%5%6%7%38%
48604
Night
12%6%2442445%7%43%
48083
TransparencyDay
42%8%11%18%15%3
48305
Night
39%7%11%20%17%4
47886
SeeingDay
15%8%19%23%20%12%
5591
Night
15%10%21%28%21%3
15748

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 15thDay
18%10%25%5%3334437%
1611
16th to endDay
16%8%35%5%2435%441%
1773
February1st to 15thDay
17%10%46%5%23446%35%
1750
16th to endDay
18%7%37%414446%35%
1580
March1st to 15thDay
17%9%25%5%2445%6%36%
1875
16th to endDay
15%8%25%42445%7%38%
2111
April1st to 15thDay
12%6%15%4346%5%7%41%
2101
16th to endDay
13%6%345%35%45%7%41%
2253
May1st to 15thDay
13%5%35%5%35%45%7%40%
2331
16th to endDay
9%437%5%45%5%6%8%37%
2431
June1st to 15thDay
8%426%6%37%7%8%10%34%
2340
16th to endDay
6%4245%36%7%8%10%40%
2340
July1st to 15thDay
10%5%36%6%5%6%6%8%11%29%
2340
16th to endDay
9%5%26%7%5%7%9%9%9%27%
2465
August1st to 15thDay
7%315%6%5%8%7%9%10%32%
2304
16th to endDay
14%5%37%6%5%6%7%7%8%26%
2292
September1st to 15thDay
13%6%36%7%45%6%6%9%32%
2006
16th to endDay
14%425%435%45%8%42%
1980
October1st to 15thDay
11%314424345%55%
1980
16th to endDay
13%42332223357%
1890
November1st to 15thDay
14%5%24323235%52%
1717
16th to endDay
14%6%24324346%46%
1755
December1st to 15thDay
16%9%37%5%2445%6%35%
1651
16th to endDay
22%9%34423335%35%
1728
January1st to 15thNight
16%8%26%5%35%345%37%
2327
16th to endNight
17%8%45%435%445%38%
2450
February1st to 15thNight
15%9%25%424336%42%
2103
16th to endNight
18%9%36%42434437%
1893
March1st to 15thNight
15%8%35%4335%5%6%39%
2085
16th to endNight
14%8%35%42435%5%43%
2112
April1st to 15thNight
12%413314448%50%
1856
16th to endNight
10%6%25%32435%6%48%
1707
May1st to 15thNight
12%5%2443446%7%44%
1619
16th to endNight
7%425%426%6%6%9%45%
1682
June1st to 15thNight
5%2246%45%5%8%12%41%
1620
16th to endNight
3224435%5%8%12%47%
1620
July1st to 15thNight
8%4235%36%6%7%12%39%
1620
16th to endNight
6%3145%35%6%10%12%39%
1703
August1st to 15thNight
5%314435%7%8%11%43%
1653
16th to endNight
8%5%245%25%6%7%11%37%
1910
September1st to 15thNight
9%4246%445%6%9%40%
1941
16th to endNight
9%5%243335%5%7%49%
1980
October1st to 15thNight
12%413323335%56%
1980
16th to endNight
11%5%2331423456%
2329
November1st to 15thNight
12%5%23323346%53%
2471
16th to endNight
14%6%24424335%48%
2535
December1st to 15thNight
16%8%35%5%24446%37%
2391
16th to endNight
19%10%45%424346%33%
2496

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
49%46%16%18%3
1612
16th to endDay
46%38%20%16%4
1773
February1st to 15thDay
49%5%7%19%16%1
1752
16th to endDay
49%5%7%16%17%3
1580
March1st to 15thDay
48%5%8%16%17%3
1875
16th to endDay
45%6%11%20%12%1
2112
April1st to 15thDay
39%7%11%21%16%3
2101
16th to endDay
42%6%8%21%16%4
2253
May1st to 15thDay
42%8%11%20%13%3
2331
16th to endDay
42%10%13%18%12%2
2435
June1st to 15thDay
39%13%15%21%8%
2340
16th to endDay
34%13%15%19%14%2
2340
July1st to 15thDay
44%12%16%17%7%2
2201
16th to endDay
44%14%16%14%9%
2310
August1st to 15thDay
40%14%15%17%9%1
2291
16th to endDay
49%12%13%14%8%1
2292
September1st to 15thDay
46%11%12%13%11%3
2006
16th to endDay
39%7%12%18%19%3
1980
October1st to 15thDay
31%6%9%18%26%6%
1980
16th to endDay
31%45%22%28%7%
1890
November1st to 15thDay
36%35%17%28%7%
1717
16th to endDay
38%5%6%18%26%5%
1755
December1st to 15thDay
48%5%7%18%15%3
1651
16th to endDay
51%49%15%14%2
1728
January1st to 15thNight
49%47%15%18%3
2327
16th to endNight
47%5%6%18%17%4
2450
February1st to 15thNight
45%48%18%18%4
2112
16th to endNight
49%46%20%17%2
1893
March1st to 15thNight
45%6%8%17%16%5%
2085
16th to endNight
41%5%12%24%14%1
2112
April1st to 15thNight
32%5%11%24%21%4
1856
16th to endNight
35%5%10%24%19%4
1707
May1st to 15thNight
38%8%13%21%16%1
1620
16th to endNight
32%12%16%23%12%2
1684
June1st to 15thNight
31%11%20%24%10%1
1620
16th to endNight
27%10%22%20%15%3
1620
July1st to 15thNight
34%10%20%21%10%2
1530
16th to endNight
31%12%21%21%11%2
1595
August1st to 15thNight
32%12%18%22%12%2
1642
16th to endNight
36%11%17%20%11%1
1910
September1st to 15thNight
38%9%16%17%13%3
1941
16th to endNight
32%7%12%22%21%3
1980
October1st to 15thNight
31%49%20%25%7%
1980
16th to endNight
32%3420%28%10%
2329
November1st to 15thNight
33%46%19%25%9%
2471
16th to endNight
38%46%18%25%7%
2535
December1st to 15thNight
47%5%9%15%17%4
2391
16th to endNight
51%5%8%16%15%2
2496

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
24%21%34%12%7%
90
16th to endDay
18%37%37%6%
96
February1st to 15thDay
26%28%36%7%
90
16th to endDay
29%19%37%13%
81
March1st to 15thDay
24%19%31%18%41
165
16th to endDay
19%15%30%21%11%
288
April1st to 15thDay
19%15%25%21%14%2
270
16th to endDay
15%9%22%29%17%5%
270
May1st to 15thDay
18%12%24%18%14%11%
288
16th to endDay
13%418%29%18%16%
331
June1st to 15thDay
9%39%25%32%19%
315
16th to endDay
9%214%26%23%23%
315
July1st to 15thDay
11%310%24%26%22%
305
16th to endDay
8%5%20%29%34%
326
August1st to 15thDay
10%114%22%25%25%
313
16th to endDay
15%19%20%32%19%
332
September1st to 15thDay
14%5%9%18%32%19%
315
16th to endDay
13%310%30%29%12%
314
October1st to 15thDay
14%419%33%20%6%
315
16th to endDay
16%9%19%24%25%3
306
November1st to 15thDay
24%11%28%25%9%
135
16th to endDay
12%16%35%22%11%1
135
December1st to 15thDay
26%19%33%17%5%
100
16th to endDay
29%18%37%10%4
96
January1st to 15thNight
22%21%28%21%5%
720
16th to endNight
21%20%27%26%3
768
February1st to 15thNight
19%18%32%26%3
704
16th to endNight
25%19%32%19%3
631
March1st to 15thNight
21%15%33%22%6%
720
16th to endNight
19%13%28%26%11%
768
April1st to 15thNight
13%14%29%30%10%
598
16th to endNight
12%8%32%31%14%
540
May1st to 15thNight
12%5%26%31%19%4
540
16th to endNight
9%114%36%29%7%
563
June1st to 15thNight
6%112%31%40%6%
540
16th to endNight
5%9%30%41%13%
540
July1st to 15thNight
10%7%28%41%11%
510
16th to endNight
5%16%22%49%14%
564
August1st to 15thNight
7%5%28%47%10%
539
16th to endNight
9%17%28%44%8%
573
September1st to 15thNight
12%29%26%40%8%
681
16th to endNight
11%115%31%35%3
717
October1st to 15thNight
13%6%19%29%25%6%
720
16th to endNight
14%9%22%29%22%2
768
November1st to 15thNight
13%10%21%32%19%2
760
16th to endNight
17%15%23%28%13%
780
December1st to 15thNight
20%14%24%30%8%
736
16th to endNight
23%17%25%27%5%
768
Page generated at 2017-12-05 10:19:04. Version ac04

Copyright 2017 A. Danko


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