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 2017-05-01.

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
46%
15008
21%
45659
15%
14966
53%
14966
25%
29269

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
48%
498
19%
1494
11%
498
54%
498
25%
978
May16th to endNight
66%
513
18%
1539
14%
513
68%
513
29%
976
June1st to 15thNight
69%
495
16%
1485
13%
495
71%
495
31%
933
June16th to endNight
80%
495
16%
1485
13%
495
81%
495
36%
865
July1st to 15thNight
69%
465
15%
1395
13%
465
71%
465
27%
900
July16th to endNight
76%
522
15%
1469
14%
489
77%
489
29%
941
August1st to 15thNight
78%
494
19%
1504
19%
491
78%
491
30%
932
August16th to endNight
68%
525
18%
1750
18%
525
70%
525
23%
1130
September1st to 15thNight
64%
624
18%
1779
16%
624
66%
624
26%
1187
September16th to endNight
59%
657
24%
1815
18%
657
63%
657
31%
1153
October1st to 15thNight
55%
660
33%
1815
27%
660
61%
660
36%
1083
October16th to endNight
49%
704
31%
2135
24%
704
58%
704
33%
1228
November1st to 15thNight
47%
700
29%
2276
24%
700
58%
700
31%
1283
November16th to endNight
36%
720
24%
2340
17%
720
48%
720
24%
1439
December1st to 15thNight
33%
720
19%
2340
14%
720
41%
720
19%
1582
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%
46097
Night
12%6%2442445%7%43%
45857
TransparencyDay
43%8%11%18%15%3
45798
Night
39%6%11%19%17%4
45660
SeeingDay
15%8%18%22%20%13%
4767
Night
15%10%21%28%20%3
15011

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%36%5%35%5%5%8%38%
2138
16th to endDay
9%437%5%45%5%6%8%38%
2223
June1st to 15thDay
8%425%6%36%7%9%10%34%
2145
16th to endDay
5%3235%36%7%8%11%41%
2145
July1st to 15thDay
11%5%36%6%5%6%6%8%11%28%
2145
16th to endDay
10%5%26%7%5%7%9%9%10%25%
2283
August1st to 15thDay
6%3146%5%8%7%9%11%34%
2112
16th to endDay
14%5%37%7%5%6%8%6%8%26%
2100
September1st to 15thDay
13%5%25%7%45%6%6%9%31%
1839
16th to endDay
15%5%25%435%45%8%40%
1815
October1st to 15thDay
11%314424345%54%
1815
16th to endDay
14%32332223456%
1733
November1st to 15thDay
13%5%23323235%54%
1582
16th to endDay
15%6%34314346%45%
1620
December1st to 15thDay
16%9%37%5%2445%6%35%
1620
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%6%24435%46%8%42%
1493
16th to endNight
7%425%425%6%6%10%45%
1538
June1st to 15thNight
5%2246%45%5%8%12%42%
1485
16th to endNight
2223435%5%8%12%49%
1485
July1st to 15thNight
9%4235%37%6%7%12%37%
1485
16th to endNight
6%3245%35%6%9%13%38%
1577
August1st to 15thNight
4214436%6%8%11%44%
1515
16th to endNight
9%6%35%435%6%7%11%37%
1750
September1st to 15thNight
8%425%7%446%7%10%39%
1779
16th to endNight
10%5%244335%5%7%46%
1815
October1st to 15thNight
13%313323335%55%
1815
16th to endNight
11%5%2431323456%
2135
November1st to 15thNight
12%5%23312346%54%
2276
16th to endNight
14%6%24424335%47%
2340
December1st to 15thNight
17%8%35%5%24446%37%
2340
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
43%9%12%19%12%2
2138
16th to endDay
41%10%13%18%13%3
2227
June1st to 15thDay
39%13%15%22%8%
2145
16th to endDay
32%13%16%20%14%3
2145
July1st to 15thDay
45%12%16%17%6%2
2006
16th to endDay
45%14%17%13%7%
2128
August1st to 15thDay
39%14%16%18%10%1
2099
16th to endDay
50%12%12%13%8%1
2100
September1st to 15thDay
46%11%13%13%11%4
1839
16th to endDay
42%6%11%16%19%3
1815
October1st to 15thDay
31%6%9%18%26%7%
1815
16th to endDay
32%45%21%27%7%
1733
November1st to 15thDay
35%35%17%30%8%
1582
16th to endDay
39%46%17%25%5%
1620
December1st to 15thDay
48%5%8%18%15%3
1620
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
39%9%14%20%14%1
1494
16th to endNight
32%12%17%23%12%2
1540
June1st to 15thNight
31%11%20%25%9%1
1485
16th to endNight
25%11%23%20%15%3
1485
July1st to 15thNight
36%10%19%20%11%1
1395
16th to endNight
32%12%22%21%10%1
1469
August1st to 15thNight
30%12%18%23%12%2
1504
16th to endNight
37%12%17%20%11%1
1750
September1st to 15thNight
38%10%17%16%12%4
1779
16th to endNight
35%7%11%20%20%3
1815
October1st to 15thNight
31%410%19%25%8%
1815
16th to endNight
33%3420%28%9%
2135
November1st to 15thNight
33%35%18%27%10%
2276
16th to endNight
40%36%18%24%6%
2340
December1st to 15thNight
47%5%8%15%17%4
2340
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
17%10%24%19%14%13%
229
16th to endDay
11%214%29%21%20%
267
June1st to 15thDay
7%210%25%34%19%
255
16th to endDay
5%112%27%25%27%
255
July1st to 15thDay
11%39%24%26%24%
245
16th to endDay
8%320%28%38%
270
August1st to 15thDay
8%19%22%28%30%
253
16th to endDay
17%16%18%34%21%
268
September1st to 15thDay
12%27%19%35%22%
255
16th to endDay
16%411%28%27%11%
254
October1st to 15thDay
16%421%29%20%7%
255
16th to endDay
17%7%19%26%25%4
245
November1st to 15thDay
21%14%24%25%13%1
90
16th to endDay
17%17%33%18%12%
90
December1st to 15thDay
28%21%33%11%5%
90
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%6%26%30%19%4
498
16th to endNight
9%213%35%31%7%
515
June1st to 15thNight
6%113%32%41%5%
495
16th to endNight
48%29%44%13%
495
July1st to 15thNight
11%17%30%39%10%
465
16th to endNight
5%16%23%50%13%
522
August1st to 15thNight
6%5%28%47%10%
494
16th to endNight
10%17%27%44%8%
525
September1st to 15thNight
11%19%27%41%8%
624
16th to endNight
12%216%33%33%2
657
October1st to 15thNight
13%6%20%28%24%6%
660
16th to endNight
14%9%21%29%22%2
704
November1st to 15thNight
13%11%22%30%19%3
700
16th to endNight
18%16%24%27%12%
720
December1st to 15thNight
20%15%25%30%8%
720
16th to endNight
23%17%25%27%5%
768
Page generated at 2017-05-02 08:43:41. Version ac04

Copyright 2017 A. Danko


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