Smokedaddy(s) Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Smokedaddy(s) Observatory clear sky chart from 2005-11-05 to 2017-10-06.

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
66%
15659
34%
47119
27%
15619
74%
15619
48%
23234

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
53%
720
30%
2327
23%
716
65%
716
39%
1183
January16th to endNight
53%
768
35%
2496
28%
768
66%
768
38%
1288
February1st to 15thNight
59%
700
33%
2218
26%
700
72%
700
44%
1095
February16th to endNight
53%
632
36%
1875
29%
632
65%
632
43%
997
March1st to 15thNight
57%
720
37%
1980
27%
720
68%
720
48%
1027
March16th to endNight
64%
768
37%
2112
25%
768
74%
768
55%
1042
April1st to 15thNight
54%
686
32%
1945
17%
686
66%
686
49%
983
April16th to endNight
60%
540
42%
1704
29%
540
74%
540
58%
704
May1st to 15thNight
66%
539
37%
1619
27%
539
74%
539
57%
718
May16th to endNight
71%
561
37%
1684
29%
561
76%
561
65%
701
June1st to 15thNight
73%
540
33%
1620
29%
540
75%
540
66%
683
June16th to endNight
84%
540
34%
1620
30%
540
85%
540
68%
670
July1st to 15thNight
80%
510
20%
1530
17%
510
80%
510
41%
817
July16th to endNight
78%
564
19%
1593
16%
531
78%
531
36%
925
August1st to 15thNight
81%
539
27%
1611
23%
536
81%
536
40%
878
August16th to endNight
85%
600
32%
1830
30%
600
85%
600
42%
998
September1st to 15thNight
79%
720
30%
1980
24%
720
82%
720
47%
1077
September16th to endNight
79%
716
43%
1980
32%
716
84%
716
65%
908
October1st to 15thNight
68%
684
38%
1974
28%
684
75%
684
59%
909
October16th to endNight
73%
704
41%
2112
33%
704
80%
704
57%
967
November1st to 15thNight
65%
700
38%
2133
28%
700
77%
700
56%
985
November16th to endNight
61%
720
39%
2340
32%
720
73%
720
48%
1079
December1st to 15thNight
58%
720
34%
2340
29%
720
68%
720
40%
1193
December16th to endNight
50%
768
31%
2496
25%
768
60%
768
33%
1407

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
5%313323446%60%
48074
Night
5%312313346%64%
47315
TransparencyDay
23%35%15%28%22%
47769
Night
20%35%16%28%24%
47121
SeeingDay
9%14%30%30%11%2
5483
Night
6%416%35%30%6%
15666

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 15thDay
8%413213345%61%
1611
16th to endDay
10%6%12213236%59%
1728
February1st to 15thDay
5%8%23212345%59%
1643
16th to endDay
10%7%14313346%53%
1597
March1st to 15thDay
6%5%12312346%61%
1980
16th to endDay
5%423213235%64%
2112
April1st to 15thDay
421332245%6%62%
2003
16th to endDay
4312212245%69%
2253
May1st to 15thDay
323213346%68%
2331
16th to endDay
321121333471%
2429
June1st to 15thDay
11211222478%
2340
16th to endDay
1121323476%
2340
July1st to 15thDay
42245%37%7%7%9%45%
2340
16th to endDay
6%436%7%47%8%8%8%34%
2467
August1st to 15thDay
6%3246%37%5%7%8%44%
2340
16th to endDay
5%3247%35%6%6%8%46%
2366
September1st to 15thDay
5%325%6%35%6%5%6%49%
1980
16th to endDay
321221224374%
1980
October1st to 15thDay
321222234470%
1783
16th to endDay
311222236%71%
1760
November1st to 15thDay
3312213435%68%
1723
16th to endDay
6%3221223469%
1620
December1st to 15thDay
9%5%13323236%57%
1620
16th to endDay
12%7%34312335%51%
1728
January1st to 15thNight
7%323323335%61%
2327
16th to endNight
10%5%1222333459%
2496
February1st to 15thNight
5%5%22212246%63%
2207
16th to endNight
8%423223347%57%
1875
March1st to 15thNight
5%5%12212345%64%
1980
16th to endNight
4212213346%67%
2112
April1st to 15thNight
6%213212337%64%
1945
16th to endNight
2112111235%76%
1704
May1st to 15thNight
2112222246%71%
1619
16th to endNight
21121223478%
1684
June1st to 15thNight
221111335%77%
1620
16th to endNight
11111123478%
1620
July1st to 15thNight
32145%25%6%7%8%52%
1620
16th to endNight
3325%5%35%7%8%12%41%
1701
August1st to 15thNight
31135%35%6%7%9%50%
1620
16th to endNight
12145%35%7%7%8%51%
1830
September1st to 15thNight
431332446%8%57%
1980
16th to endNight
311212235%75%
1980
October1st to 15thNight
3212212245%72%
1974
16th to endNight
221221232473%
2112
November1st to 15thNight
4212213335%69%
2133
16th to endNight
5%31221223468%
2340
December1st to 15thNight
8%413323335%59%
2340
16th to endNight
12%6%24313445%52%
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
24%3418%31%18%
1612
16th to endDay
27%2417%32%15%
1728
February1st to 15thDay
26%25%18%25%21%
1643
16th to endDay
31%2319%28%14%
1597
March1st to 15thDay
23%2216%36%19%
1980
16th to endDay
22%1417%36%17%
2112
April1st to 15thDay
21%2318%34%19%
2003
16th to endDay
17%1215%37%25%
2253
May1st to 15thDay
16%2415%32%28%
2331
16th to endDay
16%2312%35%28%
2432
June1st to 15thDay
11%216%31%46%
2340
16th to endDay
11%225%24%53%
2340
July1st to 15thDay
27%8%11%16%15%20%
2201
16th to endDay
37%11%15%19%14%2
2312
August1st to 15thDay
32%7%8%17%18%14%
2325
16th to endDay
31%7%9%19%22%10%
2366
September1st to 15thDay
29%6%8%14%22%16%
1980
16th to endDay
14%3112%37%30%
1980
October1st to 15thDay
17%3414%29%30%
1783
16th to endDay
15%2412%35%29%
1760
November1st to 15thDay
18%3219%32%24%
1723
16th to endDay
19%1217%30%28%
1620
December1st to 15thDay
28%27%20%26%12%
1620
16th to endDay
35%25%21%26%8%
1728
January1st to 15thNight
25%35%16%31%17%
2327
16th to endNight
28%1317%29%18%
2496
February1st to 15thNight
24%15%19%25%23%
2218
16th to endNight
26%2318%31%16%
1875
March1st to 15thNight
22%2214%34%23%
1980
16th to endNight
18%25%19%38%16%
2112
April1st to 15thNight
21%2317%34%21%
1945
16th to endNight
12%1315%37%30%
1704
May1st to 15thNight
14%2418%31%29%
1620
16th to endNight
11%1412%39%31%
1685
June1st to 15thNight
11%216%24%54%
1620
16th to endNight
10%225%18%61%
1620
July1st to 15thNight
23%7%13%14%17%22%
1530
16th to endNight
29%7%20%20%16%4
1593
August1st to 15thNight
24%8%11%21%17%17%
1611
16th to endNight
24%6%11%20%23%12%
1830
September1st to 15thNight
22%5%12%19%21%18%
1980
16th to endNight
12%2211%36%33%
1980
October1st to 15thNight
15%2417%28%32%
1974
16th to endNight
15%3411%28%37%
2112
November1st to 15thNight
17%2318%34%24%
2133
16th to endNight
20%1315%28%30%
2340
December1st to 15thNight
26%2420%26%18%
2340
16th to endNight
33%26%19%26%10%
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
33%6%30%23%5%1
90
16th to endDay
19%14%17%26%17%4
96
February1st to 15thDay
8%15%35%24%14%1
158
16th to endDay
18%29%27%17%6%
238
March1st to 15thDay
12%22%34%18%10%1
270
16th to endDay
11%24%34%20%8%1
288
April1st to 15thDay
13%23%37%15%8%1
269
16th to endDay
13%33%32%14%5%
270
May1st to 15thDay
9%25%38%20%42
288
16th to endDay
6%24%36%23%7%1
330
June1st to 15thDay
319%45%21%8%2
315
16th to endDay
3439%37%11%2
315
July1st to 15thDay
5%428%43%14%2
305
16th to endDay
8%114%46%20%7%
327
August1st to 15thDay
7%120%46%20%5%
315
16th to endDay
5%218%48%19%6%
332
September1st to 15thDay
8%5%29%39%14%3
315
16th to endDay
9%11%28%38%8%3
315
October1st to 15thDay
418%34%29%11%2
185
16th to endDay
10%7%27%35%17%2
96
November1st to 15thDay
8%5%27%32%22%3
90
16th to endDay
12%17%33%26%10%
90
December1st to 15thDay
8%425%42%16%2
90
16th to endDay
23%9%25%34%5%2
96
January1st to 15thNight
10%6%23%40%15%3
720
16th to endNight
13%6%20%37%18%2
768
February1st to 15thNight
8%6%19%42%20%1
704
16th to endNight
12%425%39%15%2
632
March1st to 15thNight
9%8%20%35%23%2
720
16th to endNight
48%19%39%24%3
768
April1st to 15thNight
7%7%24%37%20%1
686
16th to endNight
211%22%38%20%4
540
May1st to 15thNight
36%19%41%25%3
540
16th to endNight
35%16%37%32%4
563
June1st to 15thNight
3316%38%34%3
540
16th to endNight
118%35%48%5%
540
July1st to 15thNight
3426%55%9%
510
16th to endNight
3218%55%18%
564
August1st to 15thNight
4215%61%15%
539
16th to endNight
1220%56%18%
600
September1st to 15thNight
5%15%23%54%10%
720
16th to endNight
4111%33%38%10%
716
October1st to 15thNight
4418%40%27%4
684
16th to endNight
3314%40%30%6%
704
November1st to 15thNight
5%222%40%25%5%
700
16th to endNight
9%5%19%36%22%6%
720
December1st to 15thNight
12%5%19%39%22%2
720
16th to endNight
16%5%20%39%14%3
768
Page generated at 2017-10-07 11:07:54. Version ac04

Copyright 2017 A. Danko


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