Wolf Creek Observing Site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wolf Creek Observing Site clear sky chart from 2005-11-05 to 2017-09-24.

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
47%
15881
21%
47078
15%
15843
53%
15843
32%
27696

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
39%
717
18%
2327
13%
716
45%
716
24%
1469
January16th to endNight
39%
768
21%
2496
17%
768
47%
768
28%
1475
February1st to 15thNight
34%
697
17%
2288
11%
697
43%
697
24%
1416
February16th to endNight
30%
632
18%
1938
12%
632
39%
632
24%
1210
March1st to 15thNight
41%
720
19%
1992
12%
720
48%
720
33%
1199
March16th to endNight
37%
768
16%
2112
9%
768
42%
768
27%
1325
April1st to 15thNight
34%
624
15%
1883
9%
624
40%
624
24%
1173
April16th to endNight
37%
540
22%
1623
13%
540
45%
540
29%
944
May1st to 15thNight
44%
540
21%
1620
13%
540
50%
540
32%
934
May16th to endNight
48%
562
18%
1673
14%
561
52%
561
30%
994
June1st to 15thNight
51%
540
21%
1440
14%
540
57%
540
39%
826
June16th to endNight
59%
540
30%
1461
22%
540
67%
540
58%
713
July1st to 15thNight
67%
510
16%
1530
14%
510
70%
510
35%
875
July16th to endNight
70%
564
19%
1593
18%
531
71%
531
35%
929
August1st to 15thNight
64%
539
20%
1611
16%
536
67%
536
36%
905
August16th to endNight
73%
573
34%
1757
28%
573
77%
573
44%
894
September1st to 15thNight
70%
645
30%
1905
23%
645
77%
645
49%
971
September16th to endNight
65%
692
35%
1914
25%
692
71%
692
49%
1003
October1st to 15thNight
49%
660
26%
1944
18%
660
56%
660
38%
1083
October16th to endNight
50%
704
29%
2112
19%
704
60%
704
36%
1161
November1st to 15thNight
47%
700
24%
2245
19%
700
54%
700
32%
1266
November16th to endNight
41%
843
22%
2463
15%
843
48%
843
31%
1445
December1st to 15thNight
31%
900
12%
2520
7%
900
35%
900
26%
1634
December16th to endNight
30%
903
14%
2631
9%
903
35%
903
20%
1852

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%8%36%6%3445%6%44%
47844
Night
36%35%5%345%5%6%48%
47272
TransparencyDay
36%6%12%20%16%7%
47539
Night
29%8%15%23%17%6%
47078
SeeingDay
12%20%33%22%9%1
5628
Night
7%13%26%30%18%3
15892

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
28%47%9%3445%7%42%
1611
16th to endDay
312%5%7%5%34436%43%
1728
February1st to 15thDay
212%6%9%7%36%5%5%6%35%
1575
16th to endDay
313%10%10%6%24447%31%
1534
March1st to 15thDay
111%5%8%7%345%5%7%38%
1968
16th to endDay
313%5%9%8%35%5%5%6%32%
2112
April1st to 15thDay
413%5%8%5%35%446%37%
2064
16th to endDay
5%12%5%8%6%2445%6%37%
2335
May1st to 15thDay
7%10%36%6%35%5%5%6%39%
2331
16th to endDay
10%11%36%7%35%45%6%35%
2438
June1st to 15thDay
7%5%245%34346%51%
2520
16th to endDay
3312323335%66%
2495
July1st to 15thDay
9%5%25%5%35%5%5%5%46%
2340
16th to endDay
9%5%35%5%45%5%45%45%
2467
August1st to 15thDay
7%425%6%35%5%6%6%46%
2340
16th to endDay
7%3145%346%5%6%50%
2444
September1st to 15thDay
8%413434446%54%
2052
16th to endDay
8%413423335%59%
1904
October1st to 15thDay
9%9%25%423345%48%
1686
16th to endDay
6%6%36%42345%5%52%
1760
November1st to 15thDay
48%36%6%23345%50%
1613
16th to endDay
28%37%6%35%5%6%7%44%
1485
December1st to 15thDay
211%38%8%46%5%6%7%35%
1440
16th to endDay
312%5%12%8%4445%434%
1602
January1st to 15thNight
28%45%7%3446%7%43%
2327
16th to endNight
29%36%6%35%5%5%7%44%
2496
February1st to 15thNight
17%5%6%6%35%5%7%7%43%
2277
16th to endNight
29%47%7%35%5%6%8%39%
1938
March1st to 15thNight
25%46%6%35%7%5%7%45%
1992
16th to endNight
38%36%6%35%5%6%7%43%
2112
April1st to 15thNight
412%35%5%34446%45%
1883
16th to endNight
47%25%435%5%5%7%46%
1623
May1st to 15thNight
46%345%346%6%6%50%
1619
16th to endNight
6%6%25%5%35%5%7%7%44%
1672
June1st to 15thNight
432442435%6%56%
1440
16th to endNight
3112313345%69%
1461
July1st to 15thNight
44245%35%36%7%51%
1620
16th to endNight
4325%5%36%6%6%7%47%
1701
August1st to 15thNight
5%4245%35%46%7%50%
1620
16th to endNight
321433446%8%57%
1757
September1st to 15thNight
5%31331345%7%60%
1905
16th to endNight
8%413212335%65%
1914
October1st to 15thNight
5%5%25%424345%56%
1944
16th to endNight
46%2441345%7%54%
2112
November1st to 15thNight
26%26%6%345%6%6%50%
2245
16th to endNight
17%27%6%25%5%5%6%48%
2463
December1st to 15thNight
29%36%6%36%5%5%7%42%
2520
16th to endNight
311%5%9%9%35%6%5%5%34%
2631

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
34%13%21%20%9%
1612
16th to endDay
38%8%16%19%12%3
1728
February1st to 15thDay
42%14%13%18%8%3
1575
16th to endDay
47%8%15%20%6%
1534
March1st to 15thDay
40%7%19%20%10%2
1968
16th to endDay
46%8%18%17%7%2
2112
April1st to 15thDay
42%7%15%21%11%1
2064
16th to endDay
43%7%13%23%11%
2335
May1st to 15thDay
41%6%11%23%15%1
2331
16th to endDay
45%5%12%21%13%1
2441
June1st to 15thDay
31%49%21%26%6%
2520
16th to endDay
19%35%13%31%26%
2495
July1st to 15thDay
36%48%14%16%20%
2201
16th to endDay
36%5%7%13%18%18%
2312
August1st to 15thDay
33%5%10%15%15%18%
2325
16th to endDay
29%5%8%19%26%10%
2444
September1st to 15thDay
29%5%7%17%23%15%
2052
16th to endDay
26%47%24%29%7%
1904
October1st to 15thDay
35%5%11%26%19%2
1686
16th to endDay
30%411%30%20%2
1760
November1st to 15thDay
32%7%14%23%18%3
1613
16th to endDay
31%8%19%24%14%2
1485
December1st to 15thDay
40%12%19%20%6%
1440
16th to endDay
48%9%14%17%8%1
1602
January1st to 15thNight
32%13%18%21%11%2
2327
16th to endNight
30%9%19%21%12%5%
2496
February1st to 15thNight
31%13%18%20%14%1
2288
16th to endNight
35%8%17%24%11%1
1938
March1st to 15thNight
29%8%22%25%12%2
1992
16th to endNight
32%9%19%25%8%3
2112
April1st to 15thNight
34%8%16%22%14%2
1883
16th to endNight
30%6%18%29%13%
1623
May1st to 15thNight
27%9%14%30%15%2
1620
16th to endNight
33%6%16%28%14%1
1673
June1st to 15thNight
26%5%10%21%28%7%
1440
16th to endNight
16%25%15%28%31%
1461
July1st to 15thNight
30%5%10%14%16%21%
1530
16th to endNight
30%6%10%16%16%18%
1593
August1st to 15thNight
29%5%13%15%17%17%
1611
16th to endNight
22%5%8%21%30%11%
1757
September1st to 15thNight
21%410%20%26%16%
1905
16th to endNight
21%36%25%33%8%
1914
October1st to 15thNight
26%5%13%29%22%3
1944
16th to endNight
24%7%12%27%24%2
2112
November1st to 15thNight
28%7%16%24%17%5%
2245
16th to endNight
29%7%17%25%16%3
2463
December1st to 15thNight
33%11%22%22%9%
2520
16th to endNight
44%10%17%18%7%2
2631

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%20%28%23%10%1
90
16th to endDay
11%16%38%21%9%2
96
February1st to 15thDay
17%25%22%22%10%2
90
16th to endDay
16%35%33%10%31
193
March1st to 15thDay
12%36%32%14%3
270
16th to endDay
13%38%34%12%1
288
April1st to 15thDay
19%32%26%15%41
269
16th to endDay
23%31%28%14%1
270
May1st to 15thDay
17%26%35%12%6%1
288
16th to endDay
19%21%29%17%9%1
339
June1st to 15thDay
11%16%30%22%16%2
495
16th to endDay
5%12%36%26%16%2
470
July1st to 15thDay
8%11%36%31%10%1
305
16th to endDay
9%9%44%27%8%1
327
August1st to 15thDay
9%9%45%28%5%1
315
16th to endDay
9%6%34%34%10%3
332
September1st to 15thDay
7%17%36%24%9%4
315
16th to endDay
14%18%26%25%12%2
288
October1st to 15thDay
8%20%26%29%11%3
126
16th to endDay
28%12%23%21%12%1
96
November1st to 15thDay
7%13%24%27%21%5%
90
16th to endDay
18%20%36%18%32
90
December1st to 15thDay
7%28%37%23%2
90
16th to endDay
9%22%27%32%6%2
96
January1st to 15thNight
7%15%31%29%12%3
720
16th to endNight
6%17%31%27%13%3
768
February1st to 15thNight
6%18%34%25%12%2
704
16th to endNight
8%21%35%25%9%1
632
March1st to 15thNight
6%16%30%32%11%2
720
16th to endNight
7%19%31%29%11%1
768
April1st to 15thNight
9%21%30%26%11%
624
16th to endNight
8%21%28%26%12%1
540
May1st to 15thNight
6%12%32%30%16%1
540
16th to endNight
10%11%23%30%20%4
563
June1st to 15thNight
7%10%26%34%19%1
540
16th to endNight
5%5%27%34%25%2
540
July1st to 15thNight
7%212%34%38%4
510
16th to endNight
6%11%39%38%3
564
August1st to 15thNight
7%113%43%31%2
539
16th to endNight
4112%38%37%5%
573
September1st to 15thNight
5%216%35%31%8%
645
16th to endNight
8%7%14%28%30%9%
692
October1st to 15thNight
6%13%26%26%20%5%
660
16th to endNight
6%15%23%30%19%4
704
November1st to 15thNight
415%28%29%18%3
700
16th to endNight
8%17%26%29%13%3
843
December1st to 15thNight
7%20%37%24%9%1
900
16th to endNight
9%18%34%27%9%1
903
Page generated at 2017-09-25 07:02:29. Version ac04

Copyright 2017 A. Danko


Wolf Creek Observing Site Clear Sky Chart | Charts Home