Wagner Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wagner Observatory clear sky chart from 2005-11-05 to 2017-09-17.

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
57%
16039
19%
46982
15%
16001
62%
16001
27%
29435

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
47%
717
19%
2327
14%
716
55%
716
24%
1391
January16th to endNight
47%
768
26%
2388
19%
768
56%
768
27%
1411
February1st to 15thNight
48%
701
25%
2108
18%
700
56%
700
30%
1244
February16th to endNight
51%
631
29%
1809
16%
631
65%
631
36%
984
March1st to 15thNight
50%
720
30%
1980
19%
720
60%
720
40%
1064
March16th to endNight
53%
768
29%
2112
19%
768
62%
768
35%
1182
April1st to 15thNight
59%
718
23%
1976
16%
718
65%
718
39%
1069
April16th to endNight
51%
720
26%
1875
15%
720
59%
720
32%
1124
May1st to 15thNight
68%
635
25%
1715
17%
635
72%
635
43%
931
May16th to endNight
67%
561
19%
1683
15%
561
70%
561
30%
1027
June1st to 15thNight
55%
540
7%
1620
5%
540
57%
540
16%
1200
June16th to endNight
63%
540
7%
1620
4%
540
65%
540
18%
1181
July1st to 15thNight
66%
510
6%
1530
5%
510
66%
510
17%
1168
July16th to endNight
68%
564
6%
1595
6%
531
72%
531
24%
1105
August1st to 15thNight
67%
539
6%
1668
6%
536
67%
536
20%
1186
August16th to endNight
62%
750
5%
2087
5%
750
62%
750
17%
1579
September1st to 15thNight
64%
720
5%
1980
6%
720
64%
720
17%
1473
September16th to endNight
54%
665
5%
1837
4%
665
56%
665
13%
1445
October1st to 15thNight
64%
660
23%
1860
21%
660
67%
660
28%
1164
October16th to endNight
53%
704
23%
2112
19%
704
60%
704
26%
1329
November1st to 15thNight
56%
700
29%
2101
25%
700
63%
700
35%
1167
November16th to endNight
54%
720
29%
2163
21%
720
64%
720
30%
1262
December1st to 15thNight
52%
720
24%
2340
21%
720
60%
720
27%
1373
December16th to endNight
56%
768
24%
2496
21%
768
63%
768
31%
1376

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
7%425%6%46%7%7%9%38%
47777
Night
6%425%5%35%5%7%10%43%
47185
TransparencyDay
40%9%16%16%11%4
47478
Night
33%9%18%20%14%4
46988
SeeingDay
8%9%9%19%26%26%
5877
Night
7%15%11%27%26%11%
16048

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
8%4345%35%5%8%9%41%
1611
16th to endDay
8%4245%25%5%5%8%46%
1833
February1st to 15thDay
9%4244235%6%8%48%
1750
16th to endDay
5%41442445%9%53%
1661
March1st to 15thDay
32143345%6%9%54%
1980
16th to endDay
5%4144345%6%7%51%
2111
April1st to 15thDay
3213425%47%11%52%
1972
16th to endDay
4314435%5%5%9%50%
2085
May1st to 15thDay
32133245%6%10%56%
2244
16th to endDay
7%435%6%46%6%7%10%37%
2431
June1st to 15thDay
11%7%37%8%5%7%6%7%10%24%
2340
16th to endDay
9%425%9%5%8%10%9%11%23%
2340
July1st to 15thDay
7%6%28%9%6%11%9%9%10%18%
2340
16th to endDay
7%5%27%7%6%10%11%10%11%19%
2465
August1st to 15thDay
6%438%9%6%8%8%10%11%22%
2277
16th to endDay
9%5%38%7%5%9%9%8%10%20%
2101
September1st to 15thDay
5%6%38%10%6%8%8%8%11%22%
1980
16th to endDay
10%8%48%8%6%8%7%8%9%19%
1829
October1st to 15thDay
5%427%6%46%7%8%8%36%
1768
16th to endDay
9%5%235%25%6%6%8%42%
1760
November1st to 15thDay
5%414326%5%6%8%50%
1757
16th to endDay
6%4145%35%5%48%50%
1794
December1st to 15thDay
8%5%246%35%7%5%8%41%
1620
16th to endDay
5%335%5%25%6%6%10%46%
1728
January1st to 15thNight
7%5%345%2447%11%42%
2327
16th to endNight
8%3244246%7%9%45%
2388
February1st to 15thNight
9%5%25%423347%49%
2103
16th to endNight
42134345%5%10%55%
1809
March1st to 15thNight
42134245%5%8%58%
1980
16th to endNight
3313325%5%6%8%55%
2112
April1st to 15thNight
331332346%10%56%
1976
16th to endNight
43144245%6%8%51%
1875
May1st to 15thNight
2112225%5%6%10%58%
1715
16th to endNight
6%325%425%6%8%8%44%
1682
June1st to 15thNight
11%6%36%5%46%8%7%11%27%
1620
16th to endNight
5%427%6%5%7%7%9%13%29%
1620
July1st to 15thNight
6%437%7%47%8%9%11%29%
1620
16th to endNight
4325%7%47%8%9%14%32%
1703
August1st to 15thNight
6%5%26%6%48%7%9%11%31%
1679
16th to endNight
8%5%38%7%46%8%7%11%29%
2087
September1st to 15thNight
6%5%26%7%5%8%8%10%12%26%
1980
16th to endNight
9%7%37%7%5%8%7%8%12%21%
1837
October1st to 15thNight
5%5%25%426%6%6%9%44%
1860
16th to endNight
9%6%245%3445%8%43%
2112
November1st to 15thNight
6%42432435%7%53%
2101
16th to endNight
7%325%43446%9%49%
2163
December1st to 15thNight
6%5%25%42445%8%48%
2340
16th to endNight
6%41432446%9%50%
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
37%7%12%22%15%4
1612
16th to endDay
34%6%10%23%19%5%
1833
February1st to 15thDay
33%5%10%21%19%10%
1752
16th to endDay
27%6%12%24%19%8%
1661
March1st to 15thDay
25%5%14%26%21%6%
1980
16th to endDay
31%5%13%22%18%9%
2112
April1st to 15thDay
27%7%19%23%16%5%
1972
16th to endDay
30%7%14%20%21%4
2085
May1st to 15thDay
25%6%18%25%18%5%
2244
16th to endDay
41%9%18%19%11%
2435
June1st to 15thDay
55%10%20%11%2
2340
16th to endDay
50%16%21%10%1
2340
July1st to 15thDay
57%16%19%5%
2201
16th to endDay
51%17%22%8%
2310
August1st to 15thDay
49%16%26%7%
2264
16th to endDay
56%15%20%6%
2101
September1st to 15thDay
53%16%20%8%
1980
16th to endDay
58%13%16%9%2
1829
October1st to 15thDay
41%9%14%15%15%3
1768
16th to endDay
38%7%11%17%16%9%
1760
November1st to 15thDay
31%5%10%22%20%9%
1757
16th to endDay
32%6%9%20%18%11%
1794
December1st to 15thDay
39%7%14%18%14%5%
1620
16th to endDay
32%6%15%21%17%5%
1728
January1st to 15thNight
35%6%15%24%14%3
2327
16th to endNight
31%7%12%23%18%6%
2388
February1st to 15thNight
33%48%21%20%11%
2112
16th to endNight
24%5%15%24%21%8%
1809
March1st to 15thNight
23%414%30%21%5%
1980
16th to endNight
24%6%14%27%20%6%
2112
April1st to 15thNight
21%7%17%31%16%5%
1976
16th to endNight
27%7%13%22%23%4
1875
May1st to 15thNight
19%6%19%28%20%5%
1716
16th to endNight
31%8%20%25%14%
1684
June1st to 15thNight
46%13%23%12%3
1620
16th to endNight
41%15%27%12%3
1620
July1st to 15thNight
42%19%27%9%1
1530
16th to endNight
35%16%34%13%
1595
August1st to 15thNight
38%16%31%12%
1668
16th to endNight
43%18%28%8%1
2087
September1st to 15thNight
43%17%27%10%1
1980
16th to endNight
49%17%19%10%2
1837
October1st to 15thNight
32%9%18%18%17%3
1860
16th to endNight
37%6%11%17%19%6%
2112
November1st to 15thNight
29%412%22%23%8%
2101
16th to endNight
30%7%10%21%20%10%
2163
December1st to 15thNight
33%6%14%23%17%5%
2340
16th to endNight
28%6%16%22%20%4
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
16%6%27%30%16%2
90
16th to endDay
17%12%25%28%12%4
96
February1st to 15thDay
25%31%32%20%8%
90
16th to endDay
6%9%27%40%15%
162
March1st to 15thDay
314%22%34%20%4
270
16th to endDay
5%17%15%31%26%4
288
April1st to 15thDay
314%19%26%29%6%
270
16th to endDay
8%11%12%26%32%7%
270
May1st to 15thDay
5%10%10%25%30%17%
288
16th to endDay
310%415%35%30%
331
June1st to 15thDay
15%11%411%24%33%
315
16th to endDay
5%10%10%22%51%
315
July1st to 15thDay
46%423%60%
305
16th to endDay
9%10%26%24%47%
326
August1st to 15thDay
7%5%17%24%53%
313
16th to endDay
12%6%111%25%43%
332
September1st to 15thDay
7%6%25%32%45%
315
16th to endDay
12%6%27%28%41%
259
October1st to 15thDay
5%7%8%23%34%19%
255
16th to endDay
14%7%17%26%24%9%
272
November1st to 15thDay
8%10%10%27%29%13%
265
16th to endDay
6%11%18%33%25%4
264
December1st to 15thDay
24%114%37%21%1
90
16th to endDay
3113%39%33%9%
96
January1st to 15thNight
10%20%16%32%19%
720
16th to endNight
7%20%20%37%13%
768
February1st to 15thNight
7%19%18%38%15%
704
16th to endNight
5%18%20%40%15%
631
March1st to 15thNight
5%19%20%37%16%1
720
16th to endNight
5%19%17%38%18%
768
April1st to 15thNight
418%13%40%21%
718
16th to endNight
6%17%14%39%21%
720
May1st to 15thNight
317%8%38%29%2
636
16th to endNight
317%225%41%8%
563
June1st to 15thNight
10%17%213%37%18%
540
16th to endNight
417%110%33%32%
540
July1st to 15thNight
5%11%1336%41%
510
16th to endNight
316%15%30%42%
564
August1st to 15thNight
7%9%1436%39%
539
16th to endNight
10%8%39%36%30%
750
September1st to 15thNight
7%8%312%39%28%
720
16th to endNight
12%9%415%37%20%
665
October1st to 15thNight
8%9%6%28%36%10%
660
16th to endNight
13%10%14%30%24%6%
704
November1st to 15thNight
6%15%16%34%24%3
700
16th to endNight
6%17%14%36%21%2
720
December1st to 15thNight
7%19%14%32%23%1
720
16th to endNight
5%17%14%30%28%2
768
Page generated at 2017-09-18 08:38:29. Version ac04

Copyright 2017 A. Danko


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