Dedication Point
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dedication Point clear sky chart from 2005-11-06 to 2024-01-13.

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
54%
22806
21%
74579
18%
22775
60%
22775
30%
43645

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 10thNight
38%
756
8%
2646
6%
756
41%
756
14%
1938
January11th to 20thNight
42%
728
11%
2548
9%
728
46%
728
15%
1826
January21st to endNight
45%
792
11%
2772
10%
792
49%
792
17%
1933
February1st to 10thNight
43%
720
12%
2345
8%
720
49%
720
21%
1542
February11th to 20thNight
49%
700
20%
2099
14%
700
58%
700
29%
1334
February21st to endNight
41%
592
18%
1776
14%
592
48%
592
24%
1179
March1st to 10thNight
42%
720
15%
2160
11%
720
50%
720
24%
1442
March11th to 20thNight
49%
720
20%
2066
15%
720
55%
720
29%
1311
March21st to endNight
41%
792
16%
2066
9%
792
45%
792
25%
1417
April1st to 10thNight
48%
720
23%
1800
10%
720
54%
720
33%
1176
April11th to 20thNight
48%
684
26%
1752
12%
684
55%
684
34%
1096
April21st to endNight
51%
540
27%
1620
16%
540
58%
540
37%
902
May1st to 10thNight
49%
540
27%
1620
17%
540
58%
540
41%
868
May11th to 20thNight
55%
461
22%
1523
20%
461
60%
461
34%
854
May21st to endNight
55%
388
17%
1552
20%
388
61%
388
25%
865
June1st to 10thNight
57%
360
17%
1440
20%
360
64%
360
27%
786
June11th to 20thNight
53%
360
23%
1440
25%
360
66%
360
36%
653
June21st to endNight
61%
360
27%
1440
35%
360
72%
360
50%
553
July1st to 10thNight
70%
350
27%
1400
35%
350
79%
350
56%
506
July11th to 20thNight
72%
348
33%
1392
39%
348
84%
348
69%
449
July21st to endNight
75%
394
35%
1488
41%
372
83%
372
57%
537
August1st to 10thNight
73%
455
32%
1521
29%
453
78%
453
50%
682
August11th to 20thNight
82%
539
39%
1607
29%
539
85%
539
70%
667
August21st to endNight
74%
792
37%
1980
22%
792
77%
792
67%
963
September1st to 10thNight
77%
720
38%
1800
23%
720
81%
720
67%
889
September11th to 20thNight
75%
720
36%
1960
27%
720
79%
720
56%
994
September21st to endNight
69%
720
36%
1980
30%
720
74%
720
54%
1006
October1st to 10thNight
62%
720
29%
1980
22%
720
69%
720
45%
1075
October11th to 20thNight
65%
720
33%
2210
30%
720
72%
720
44%
1134
October21st to endNight
58%
792
26%
2574
23%
792
67%
792
35%
1399
November1st to 10thNight
56%
740
24%
2405
23%
740
61%
740
28%
1445
November11th to 20thNight
47%
760
21%
2470
16%
760
54%
760
25%
1553
November21st to endNight
54%
760
18%
2489
14%
760
60%
760
28%
1513
December1st to 10thNight
43%
760
11%
2660
8%
760
48%
760
18%
1780
December11th to 20thNight
44%
759
10%
3212
9%
759
48%
759
13%
2293
December21st to endNight
31%
824
8%
4786
7%
817
37%
817
9%
3085

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
6%5%25%5%3445%7%52%
74840
Night
8%6%25%5%35%5%6%7%48%
74902
TransparencyDay
30%6%13%21%19%12%
74544
Night
33%7%13%21%17%10%
74719
SeeingDay
7%8%25%30%21%8%
13385
Night
9%6%23%37%22%3
22828

By Month

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 10thDay
12%10%48%8%5%6%6%6%9%26%
1519
11th to 20thDay
10%8%5%11%9%5%6%6%6%8%26%
1456
21st to endDay
10%9%49%9%47%5%6%9%26%
1584
February1st to 10thDay
7%8%5%9%7%36%6%5%7%36%
1609
11th to 20thDay
8%11%36%7%345%5%9%39%
1750
21st to endDay
6%9%48%6%46%6%7%7%36%
1480
March1st to 10thDay
8%9%5%7%6%46%6%7%8%35%
1800
11th to 20thDay
8%7%47%6%35%6%6%8%40%
1893
21st to endDay
9%9%37%6%47%7%6%9%35%
2286
April1st to 10thDay
9%7%25%6%45%5%7%10%41%
2160
11th to 20thDay
6%6%37%6%345%6%7%47%
2155
21st to endDay
7%5%245%245%6%7%52%
2340
May1st to 10thDay
5%4245%35%45%7%57%
2340
11th to 20thDay
8%5%25%5%345%6%7%50%
2368
21st to endDay
7%4245%35%5%7%10%47%
2723
June1st to 10thDay
7%5%25%425%6%7%9%48%
2520
11th to 20thDay
6%41332445%8%60%
2520
21st to endDay
221121335%6%73%
2520
July1st to 10thDay
221231435%5%72%
2520
11th to 20thDay
221212223480%
2520
21st to endDay
321222334474%
2741
August1st to 10thDay
3313324446%66%
2409
11th to 20thDay
2112212346%76%
2291
21st to endDay
221222324476%
2376
September1st to 10thDay
1212212235%77%
2160
11th to 20thDay
4323312247%68%
1999
21st to endDay
5%314323445%66%
1980
October1st to 10thDay
8%4135%24446%59%
1980
11th to 20thDay
5%42342346%8%59%
1746
21st to endDay
6%5%15%5%345%6%8%51%
1782
November1st to 10thDay
10%8%35%6%45%45%9%43%
1674
11th to 20thDay
11%6%25%6%46%5%7%9%38%
1710
21st to endDay
8%7%37%7%47%6%6%9%37%
1687
December1st to 10thDay
12%9%310%7%345%6%7%35%
1520
11th to 20thDay
13%10%410%10%45%5%6%8%25%
1928
21st to endDay
8%9%49%10%46%6%7%7%28%
2794
January1st to 10thNight
11%11%410%8%46%6%6%8%26%
2646
11th to 20thNight
10%9%49%7%46%6%6%8%30%
2548
21st to endNight
11%9%5%10%6%45%5%5%7%33%
2772
February1st to 10thNight
11%8%36%5%46%5%6%7%39%
2345
11th to 20thNight
9%7%36%5%35%6%6%9%41%
2098
21st to endNight
8%9%46%6%45%7%8%7%36%
1776
March1st to 10thNight
9%9%36%5%36%5%6%8%38%
2160
11th to 20thNight
10%8%35%5%35%46%8%43%
2066
21st to endNight
11%9%35%7%36%6%6%8%37%
2066
April1st to 10thNight
9%6%35%5%45%5%6%6%45%
1800
11th to 20thNight
8%5%25%5%46%5%5%8%48%
1752
21st to endNight
7%4245%335%6%7%54%
1620
May1st to 10thNight
5%415%33445%8%58%
1620
11th to 20thNight
6%4245%47%5%6%9%48%
1523
21st to endNight
7%436%6%45%5%6%8%45%
1552
June1st to 10thNight
8%5%25%445%5%5%9%48%
1440
11th to 20thNight
6%42332446%6%61%
1440
21st to endNight
32331345%6%68%
1440
July1st to 10thNight
221232335%6%73%
1440
11th to 20thNight
111212345%80%
1440
21st to endNight
2212323346%73%
1576
August1st to 10thNight
4412322445%68%
1529
11th to 20thNight
11221335%6%77%
1607
21st to endNight
3112223345%74%
1980
September1st to 10thNight
3212312235%76%
1800
11th to 20thNight
321331445%6%67%
1960
21st to endNight
6%312323345%67%
1980
October1st to 10thNight
7%425%324346%61%
1980
11th to 20thNight
7%413334446%61%
2210
21st to endNight
7%5%145%35%5%6%8%51%
2574
November1st to 10thNight
10%7%26%5%245%5%7%45%
2405
11th to 20thNight
14%6%36%445%5%6%8%40%
2470
21st to endNight
9%8%35%5%35%5%5%8%43%
2489
December1st to 10thNight
12%10%47%7%35%46%7%35%
2660
11th to 20thNight
14%10%49%7%46%6%6%7%27%
3276
21st to endNight
12%10%49%7%46%5%6%8%29%
4862

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 10thDay
51%13%19%15%2
1519
11th to 20thDay
52%13%18%15%2
1456
21st to endDay
51%12%21%13%3
1584
February1st to 10thDay
44%9%20%21%5%1
1609
11th to 20thDay
41%8%18%23%9%
1760
21st to endDay
42%8%18%21%11%1
1480
March1st to 10thDay
44%9%15%22%8%2
1800
11th to 20thDay
39%8%16%24%11%1
1893
21st to endDay
44%8%17%20%10%2
2286
April1st to 10thDay
38%6%15%21%16%4
2160
11th to 20thDay
34%6%14%24%18%5%
2158
21st to endDay
30%6%12%27%21%4
2340
May1st to 10thDay
26%411%26%26%6%
2340
11th to 20thDay
31%7%10%27%20%5%
2371
21st to endDay
30%8%15%25%18%4
2724
June1st to 10thDay
31%7%13%25%20%3
2520
11th to 20thDay
22%5%9%23%30%10%
2520
21st to endDay
13%37%19%35%24%
2520
July1st to 10thDay
13%37%15%29%34%
2451
11th to 20thDay
10%249%27%48%
2445
21st to endDay
14%15%7%27%45%
2589
August1st to 10thDay
18%48%14%27%29%
2392
11th to 20thDay
11%26%15%32%33%
2291
21st to endDay
13%26%14%38%28%
2376
September1st to 10thDay
12%25%15%30%35%
2160
11th to 20thDay
18%37%24%29%18%
1999
21st to endDay
21%37%24%34%12%
1980
October1st to 10thDay
27%5%11%26%25%7%
1980
11th to 20thDay
23%5%12%34%22%4
1746
21st to endDay
27%5%16%32%17%2
1782
November1st to 10thDay
39%7%14%27%14%
1674
11th to 20thDay
38%9%21%26%6%1
1710
21st to endDay
40%9%21%25%5%
1687
December1st to 10thDay
45%11%20%16%7%
1520
11th to 20thDay
52%8%23%14%3
1928
21st to endDay
46%11%19%19%5%
2794
January1st to 10thNight
52%10%21%12%3
2646
11th to 20thNight
50%10%15%20%5%
2548
21st to endNight
48%9%19%19%5%
2772
February1st to 10thNight
41%10%21%23%41
2345
11th to 20thNight
37%8%18%25%11%1
2099
21st to endNight
42%8%16%21%13%1
1776
March1st to 10thNight
42%7%14%23%11%2
2160
11th to 20thNight
37%7%12%28%15%1
2066
21st to endNight
42%8%14%25%10%1
2066
April1st to 10thNight
36%7%12%25%18%4
1800
11th to 20thNight
33%6%10%28%20%3
1752
21st to endNight
28%5%10%29%24%4
1620
May1st to 10thNight
25%5%8%23%34%5%
1620
11th to 20thNight
29%6%12%23%25%5%
1523
21st to endNight
33%8%12%26%16%5%
1552
June1st to 10thNight
33%7%13%22%22%3
1440
11th to 20thNight
23%5%8%21%34%10%
1440
21st to endNight
15%36%18%30%27%
1440
July1st to 10thNight
13%25%13%29%38%
1400
11th to 20thNight
8%15%9%26%51%
1392
21st to endNight
14%25%7%24%49%
1488
August1st to 10thNight
19%37%12%23%37%
1521
11th to 20thNight
10%25%13%29%42%
1607
21st to endNight
12%35%13%31%36%
1980
September1st to 10thNight
14%2412%28%40%
1800
11th to 20thNight
17%46%19%26%28%
1960
21st to endNight
20%35%19%33%20%
1980
October1st to 10thNight
25%49%23%28%12%
1980
11th to 20thNight
23%5%8%31%29%5%
2210
21st to endNight
28%6%13%27%23%3
2574
November1st to 10thNight
36%6%12%26%18%2
2405
11th to 20thNight
39%7%14%28%11%
2470
21st to endNight
37%6%17%29%10%
2489
December1st to 10thNight
45%8%21%17%7%1
2660
11th to 20thNight
50%10%19%19%3
3276
21st to endNight
46%12%19%18%6%
4862

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 10thDay
14%11%29%24%17%4
180
11th to 20thDay
10%9%31%27%18%5%
164
21st to endDay
13%6%23%38%16%4
176
February1st to 10thDay
6%17%33%22%17%4
276
11th to 20thDay
14%12%29%27%13%5%
415
21st to endDay
10%16%31%28%13%2
346
March1st to 10thDay
11%13%35%30%10%1
420
11th to 20thDay
10%11%32%30%16%1
420
21st to endDay
11%14%34%26%12%3
462
April1st to 10thDay
12%19%25%21%18%6%
420
11th to 20thDay
6%16%34%25%14%5%
412
21st to endDay
8%15%33%26%15%4
420
May1st to 10thDay
315%30%32%16%5%
423
11th to 20thDay
14%9%23%27%20%8%
448
21st to endDay
8%6%19%33%20%14%
485
June1st to 10thDay
6%6%26%29%21%11%
450
11th to 20thDay
5%11%26%32%20%6%
450
21st to endDay
35%28%31%22%12%
450
July1st to 10thDay
2223%41%22%10%
446
11th to 20thDay
1325%42%22%6%
444
21st to endDay
2221%35%33%8%
487
August1st to 10thDay
3223%35%28%9%
447
11th to 20thDay
2118%36%29%14%
437
21st to endDay
3318%33%27%15%
495
September1st to 10thDay
3416%30%31%16%
450
11th to 20thDay
4418%30%30%14%
450
21st to endDay
4422%32%25%12%
450
October1st to 10thDay
7%8%19%26%25%15%
450
11th to 20thDay
8%5%22%28%26%11%
358
21st to endDay
9%10%22%28%23%7%
297
November1st to 10thDay
11%10%23%34%19%3
270
11th to 20thDay
7%8%27%32%19%6%
270
21st to endDay
8%6%25%33%24%3
259
December1st to 10thDay
14%8%24%26%18%9%
180
11th to 20thDay
13%11%29%28%16%3
180
21st to endDay
10%14%29%27%16%4
198
January1st to 10thNight
11%6%28%33%18%4
760
11th to 20thNight
10%6%27%34%20%3
728
21st to endNight
12%421%34%25%4
792
February1st to 10thNight
12%7%28%36%16%2
720
11th to 20thNight
10%5%27%38%18%2
704
21st to endNight
10%7%33%35%15%1
592
March1st to 10thNight
11%8%30%35%14%2
720
11th to 20thNight
11%7%27%37%16%3
720
21st to endNight
12%10%29%33%14%1
792
April1st to 10thNight
9%8%26%35%19%2
720
11th to 20thNight
9%10%26%36%17%2
684
21st to endNight
7%9%28%38%15%3
540
May1st to 10thNight
6%9%31%34%19%2
540
11th to 20thNight
5%7%25%36%23%5%
461
21st to endNight
6%6%22%35%25%6%
389
June1st to 10thNight
9%6%21%38%20%7%
360
11th to 20thNight
6%8%29%32%22%3
360
21st to endNight
35%25%38%26%3
360
July1st to 10thNight
1321%46%27%2
350
11th to 20thNight
1222%52%23%
348
21st to endNight
2116%50%29%3
394
August1st to 10thNight
5%214%44%33%2
455
11th to 20thNight
1111%51%34%2
539
21st to endNight
3316%43%30%5%
792
September1st to 10thNight
3114%41%36%5%
720
11th to 20thNight
4313%38%36%6%
720
21st to endNight
6%417%33%30%10%
720
October1st to 10thNight
8%419%36%28%5%
720
11th to 20thNight
6%418%40%26%6%
720
21st to endNight
7%5%22%37%24%4
792
November1st to 10thNight
10%5%21%38%25%2
740
11th to 20thNight
14%7%24%34%19%3
760
21st to endNight
11%423%37%23%3
760
December1st to 10thNight
11%6%25%38%17%3
760
11th to 20thNight
14%6%22%38%18%2
760
21st to endNight
18%6%29%34%12%1
836
Page generated at 2024-01-09 23:25:06. Version ac07

Copyright 2024 Attilla Danko


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