Wayah Bald
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wayah Bald clear sky chart from 2005-11-05 to 2017-08-12.

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%
15411
19%
46556
13%
15368
52%
15368
22%
30715

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
27%
720
19%
2327
11%
716
40%
716
17%
1547
January16th to endNight
23%
768
20%
2496
9%
768
37%
768
17%
1657
February1st to 15thNight
27%
704
20%
2124
9%
701
40%
701
22%
1371
February16th to endNight
21%
631
20%
1893
9%
631
32%
631
16%
1319
March1st to 15thNight
28%
720
20%
2046
10%
720
37%
720
19%
1397
March16th to endNight
33%
768
15%
2112
9%
768
37%
768
21%
1448
April1st to 15thNight
36%
664
21%
1922
11%
664
46%
664
26%
1198
April16th to endNight
45%
540
22%
1659
14%
540
54%
540
26%
1035
May1st to 15thNight
46%
540
14%
1620
7%
540
52%
540
22%
1097
May16th to endNight
61%
561
16%
1683
11%
561
64%
561
24%
1123
June1st to 15thNight
65%
540
12%
1620
9%
540
67%
540
25%
1093
June16th to endNight
72%
540
15%
1620
13%
540
73%
540
31%
1001
July1st to 15thNight
68%
510
9%
1530
8%
510
69%
510
22%
1082
July16th to endNight
73%
564
12%
1595
11%
531
74%
531
23%
1101
August1st to 15thNight
65%
527
14%
1575
14%
524
65%
524
21%
1115
August16th to endNight
65%
525
15%
1711
16%
525
66%
525
20%
1173
September1st to 15thNight
62%
660
15%
1815
14%
660
63%
660
22%
1293
September16th to endNight
58%
657
19%
1815
16%
657
60%
657
26%
1222
October1st to 15thNight
51%
660
31%
1853
24%
660
59%
660
32%
1127
October16th to endNight
49%
704
30%
2112
22%
704
59%
704
31%
1239
November1st to 15thNight
50%
700
27%
2252
24%
700
58%
700
30%
1288
November16th to endNight
44%
720
24%
2340
19%
720
52%
720
24%
1454
December1st to 15thNight
36%
720
19%
2340
14%
720
44%
720
18%
1562
December16th to endNight
32%
768
18%
2496
12%
768
40%
768
15%
1773

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%7%36%6%35%5%5%7%34%
47417
Night
10%6%36%5%35%45%7%40%
46754
TransparencyDay
46%8%10%16%14%3
47118
Night
40%8%12%18%15%4
46557
SeeingDay
15%10%20%20%18%14%
5258
Night
14%10%20%27%22%4
15413

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
13%8%5%6%5%35%34439%
1611
16th to endDay
13%6%35%434445%44%
1728
February1st to 15thDay
12%8%27%6%35%446%38%
1736
16th to endDay
13%7%38%42345%7%39%
1580
March1st to 15thDay
14%7%36%5%2445%7%37%
1914
16th to endDay
15%8%45%5%3445%5%35%
2111
April1st to 15thDay
11%6%26%5%35%6%7%6%38%
2037
16th to endDay
14%6%36%5%34446%41%
2300
May1st to 15thDay
14%7%37%7%45%446%34%
2331
16th to endDay
13%7%37%6%45%5%6%8%30%
2431
June1st to 15thDay
10%5%38%8%5%7%7%7%8%26%
2340
16th to endDay
7%5%27%8%47%7%8%8%31%
2340
July1st to 15thDay
12%7%48%9%5%7%7%7%9%19%
2340
16th to endDay
11%6%38%8%5%8%8%7%8%22%
2465
August1st to 15thDay
10%6%47%9%5%8%7%6%10%22%
2288
16th to endDay
16%8%39%8%5%6%5%6%7%21%
2126
September1st to 15thDay
14%8%39%9%45%6%5%6%25%
1815
16th to endDay
19%6%25%6%345%5%7%33%
1815
October1st to 15thDay
13%5%23324435%50%
1777
16th to endDay
12%6%2432332454%
1760
November1st to 15thDay
11%433423335%53%
1604
16th to endDay
14%7%2442445%5%44%
1620
December1st to 15thDay
15%7%37%5%345%45%36%
1620
16th to endDay
17%9%36%5%33335%36%
1728
January1st to 15thNight
12%7%36%6%45%45%5%38%
2327
16th to endNight
11%7%47%7%34445%39%
2496
February1st to 15thNight
10%6%35%5%35%45%6%42%
2115
16th to endNight
11%6%5%8%6%35%445%36%
1893
March1st to 15thNight
11%8%47%5%35%446%38%
2046
16th to endNight
11%7%46%5%35%45%6%39%
2112
April1st to 15thNight
10%5%245%2446%6%46%
1922
16th to endNight
10%5%35%42435%7%45%
1659
May1st to 15thNight
13%5%35%6%3446%8%38%
1619
16th to endNight
7%5%25%6%45%6%7%8%40%
1682
June1st to 15thNight
7%335%5%36%6%9%11%36%
1620
16th to endNight
5%3245%36%5%8%12%43%
1620
July1st to 15thNight
8%5%25%7%47%7%7%11%32%
1620
16th to endNight
7%425%5%36%8%7%13%33%
1703
August1st to 15thNight
10%436%6%46%5%6%9%34%
1586
16th to endNight
10%6%36%5%35%6%9%9%32%
1711
September1st to 15thNight
9%5%38%6%46%7%8%8%31%
1815
16th to endNight
14%5%25%5%3445%8%39%
1815
October1st to 15thNight
12%5%23422336%51%
1853
16th to endNight
9%5%25%42333454%
2112
November1st to 15thNight
10%5%24423336%52%
2252
16th to endNight
12%7%345%34445%45%
2340
December1st to 15thNight
13%7%37%6%3445%6%37%
2340
16th to endNight
14%10%47%6%35%45%5%31%
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
46%5%8%15%18%5%
1612
16th to endDay
40%5%9%19%18%6%
1728
February1st to 15thDay
45%5%7%18%19%3
1738
16th to endDay
43%5%11%17%18%3
1580
March1st to 15thDay
45%5%9%17%17%5%
1914
16th to endDay
48%6%11%16%13%2
2112
April1st to 15thDay
40%7%12%20%16%3
2037
16th to endDay
43%6%9%20%17%3
2300
May1st to 15thDay
48%8%11%17%11%2
2331
16th to endDay
48%10%13%15%10%1
2435
June1st to 15thDay
49%12%15%17%4
2340
16th to endDay
44%12%14%16%11%1
2340
July1st to 15thDay
55%13%13%12%4
2201
16th to endDay
51%13%14%12%6%1
2310
August1st to 15thDay
50%13%12%14%6%1
2275
16th to endDay
57%10%12%12%6%1
2126
September1st to 15thDay
55%8%9%12%10%3
1815
16th to endDay
47%7%12%12%17%2
1815
October1st to 15thDay
35%6%9%17%24%6%
1777
16th to endDay
34%36%19%25%10%
1760
November1st to 15thDay
33%46%15%29%10%
1604
16th to endDay
40%47%16%24%6%
1620
December1st to 15thDay
46%7%6%14%17%6%
1620
16th to endDay
49%5%9%14%15%5%
1728
January1st to 15thNight
45%6%9%14%18%6%
2327
16th to endNight
46%5%7%15%19%5%
2496
February1st to 15thNight
41%5%11%17%19%4
2124
16th to endNight
47%6%8%18%16%2
1893
March1st to 15thNight
44%7%10%16%16%5%
2046
16th to endNight
42%7%13%19%13%1
2112
April1st to 15thNight
35%6%12%24%17%3
1922
16th to endNight
38%5%12%22%17%3
1659
May1st to 15thNight
41%9%15%20%11%1
1620
16th to endNight
37%12%16%22%9%1
1684
June1st to 15thNight
36%13%23%20%5%
1620
16th to endNight
30%12%21%22%11%1
1620
July1st to 15thNight
40%14%20%18%5%
1530
16th to endNight
36%16%22%16%6%1
1595
August1st to 15thNight
41%13%14%18%10%
1575
16th to endNight
41%12%18%18%7%1
1711
September1st to 15thNight
43%12%17%14%9%2
1815
16th to endNight
40%8%14%17%16%2
1815
October1st to 15thNight
33%6%10%21%24%4
1853
16th to endNight
33%46%19%26%8%
2112
November1st to 15thNight
33%37%17%26%10%
2252
16th to endNight
39%5%7%18%21%7%
2340
December1st to 15thNight
45%6%9%13%17%7%
2340
16th to endNight
51%6%8%13%14%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
25%20%40%10%31
90
16th to endDay
16%43%31%44
96
February1st to 15thDay
20%35%40%4
90
16th to endDay
28%29%33%7%1
81
March1st to 15thDay
24%12%29%21%11%
204
16th to endDay
18%15%28%21%12%2
288
April1st to 15thDay
17%15%24%24%14%3
270
16th to endDay
17%9%22%23%18%8%
270
May1st to 15thDay
12%21%23%16%14%11%
288
16th to endDay
15%8%18%22%16%18%
331
June1st to 15thDay
10%315%25%23%22%
315
16th to endDay
8%424%18%19%25%
315
July1st to 15thDay
9%419%21%20%23%
305
16th to endDay
7%9%22%27%32%
326
August1st to 15thDay
16%212%22%21%24%
297
16th to endDay
16%111%17%23%30%
268
September1st to 15thDay
12%38%16%35%22%
255
16th to endDay
19%314%22%27%12%
254
October1st to 15thDay
18%8%16%24%20%10%
255
16th to endDay
13%10%17%27%24%6%
272
November1st to 15thDay
18%8%28%25%13%4
112
16th to endDay
20%16%30%21%11%1
90
December1st to 15thDay
21%28%31%14%31
90
16th to endDay
25%22%39%9%3
96
January1st to 15thNight
21%18%27%24%7%
720
16th to endNight
18%18%33%26%3
768
February1st to 15thNight
19%17%31%28%3
704
16th to endNight
21%23%28%22%3
631
March1st to 15thNight
16%21%28%26%6%
720
16th to endNight
16%14%27%27%12%1
768
April1st to 15thNight
16%17%26%26%12%1
664
16th to endNight
13%9%22%32%19%2
540
May1st to 15thNight
14%7%23%27%23%3
540
16th to endNight
9%315%30%31%9%
563
June1st to 15thNight
7%112%30%37%10%
540
16th to endNight
5%11%26%43%11%
540
July1st to 15thNight
8%17%24%47%10%
510
16th to endNight
7%7%19%46%17%
564
August1st to 15thNight
11%7%25%41%13%
527
16th to endNight
11%26%20%46%12%
525
September1st to 15thNight
10%29%24%41%11%
660
16th to endNight
16%212%29%33%5%
657
October1st to 15thNight
14%8%18%24%26%7%
660
16th to endNight
12%11%21%31%19%4
704
November1st to 15thNight
12%10%19%30%22%5%
700
16th to endNight
15%14%19%33%15%1
720
December1st to 15thNight
18%14%22%32%12%1
720
16th to endNight
20%14%27%29%7%
768
Page generated at 2017-08-13 14:16:16. Version ac04

Copyright 2017 A. Danko


Wayah Bald Clear Sky Chart | Charts Home