Jeff Busby Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Jeff Busby Campground clear sky chart from 2005-11-05 to 2017-09-23.

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
49%
15456
25%
46934
18%
15412
57%
15412
31%
28167

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
29%
900
25%
2374
9%
895
41%
895
27%
1535
January16th to endNight
21%
888
24%
2424
7%
888
34%
888
24%
1624
February1st to 15thNight
27%
704
24%
2112
9%
701
40%
701
25%
1337
February16th to endNight
26%
631
26%
1893
10%
631
38%
631
24%
1203
March1st to 15thNight
30%
690
19%
2130
11%
690
38%
690
23%
1374
March16th to endNight
36%
576
25%
2004
16%
576
48%
576
26%
1163
April1st to 15thNight
39%
539
26%
1797
17%
539
53%
539
30%
1020
April16th to endNight
45%
540
27%
1800
20%
540
57%
540
33%
987
May1st to 15thNight
50%
540
20%
1788
15%
540
60%
540
30%
1041
May16th to endNight
64%
561
24%
1682
21%
561
69%
561
36%
988
June1st to 15thNight
73%
540
21%
1486
18%
540
75%
540
39%
897
June16th to endNight
74%
540
26%
1440
22%
540
76%
540
44%
823
July1st to 15thNight
79%
510
19%
1391
19%
510
80%
510
39%
837
July16th to endNight
79%
564
18%
1674
21%
531
80%
531
35%
974
August1st to 15thNight
81%
539
18%
1788
22%
536
81%
536
33%
1026
August16th to endNight
74%
573
24%
1910
29%
573
74%
573
28%
1183
September1st to 15thNight
65%
540
24%
1800
25%
540
67%
540
31%
1048
September16th to endNight
70%
680
31%
1894
26%
680
72%
680
39%
1103
October1st to 15thNight
63%
660
34%
1884
28%
660
68%
660
42%
1043
October16th to endNight
53%
704
34%
2112
27%
704
60%
704
37%
1177
November1st to 15thNight
48%
700
30%
2246
24%
700
58%
700
36%
1211
November16th to endNight
40%
720
28%
2340
20%
720
53%
720
31%
1333
December1st to 15thNight
35%
720
24%
2340
15%
720
47%
720
25%
1453
December16th to endNight
28%
897
20%
2625
10%
897
38%
897
21%
1787

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
11%5%25%5%35%5%5%7%42%
47951
Night
11%5%2442445%7%48%
47133
TransparencyDay
40%5%10%20%18%5%
47654
Night
35%410%21%20%7%
46936
SeeingDay
13%5%20%25%23%12%
5538
Night
14%7%23%28%21%4
15458

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
17%7%24323445%42%
1561
16th to endDay
16%5%2442334446%
1797
February1st to 15thDay
14%6%26%5%23345%43%
1750
16th to endDay
17%7%35%5%23235%42%
1580
March1st to 15thDay
15%8%36%6%24446%37%
1839
16th to endDay
12%6%36%5%35%45%5%41%
2218
April1st to 15thDay
12%5%24435%45%6%45%
2151
16th to endDay
10%4245%25%446%48%
2160
May1st to 15thDay
13%5%26%6%35%446%40%
2160
16th to endDay
9%425%7%46%6%6%7%38%
2431
June1st to 15thDay
5%425%7%47%6%7%9%38%
2469
16th to endDay
5%325%5%46%6%6%8%43%
2520
July1st to 15thDay
9%5%25%6%47%8%6%9%33%
2484
16th to endDay
7%5%26%7%5%8%7%8%10%30%
2376
August1st to 15thDay
6%426%6%48%7%8%9%34%
2160
16th to endDay
12%5%25%6%46%6%6%10%32%
2292
September1st to 15thDay
10%5%26%6%46%46%8%38%
2157
16th to endDay
13%5%14433445%49%
1894
October1st to 15thDay
8%424424346%53%
1744
16th to endDay
12%314322325%59%
1760
November1st to 15thDay
10%314413235%58%
1612
16th to endDay
15%6%24322335%50%
1620
December1st to 15thDay
16%8%44433346%39%
1620
16th to endDay
19%7%35%423245%40%
1596
January1st to 15thNight
15%5%24423335%48%
2374
16th to endNight
17%7%35%423335%42%
2424
February1st to 15thNight
15%6%25%424345%45%
2103
16th to endNight
15%6%25%333335%45%
1893
March1st to 15thNight
15%6%24425%45%7%41%
2130
16th to endNight
12%5%24424346%47%
2004
April1st to 15thNight
11%5%14424447%51%
1797
16th to endNight
8%32442446%8%51%
1800
May1st to 15thNight
10%42442446%8%47%
1787
16th to endNight
5%416%325%5%7%9%48%
1682
June1st to 15thNight
33145%35%5%6%9%49%
1486
16th to endNight
42144245%7%12%51%
1440
July1st to 15thNight
3324436%6%7%11%46%
1473
16th to endNight
43145%35%5%9%12%44%
1789
August1st to 15thNight
42145%35%6%8%12%44%
1800
16th to endNight
7%3245%35%5%7%10%42%
1910
September1st to 15thNight
10%4145%2445%8%48%
1800
16th to endNight
8%4133236%6%8%52%
1894
October1st to 15thNight
9%323322347%57%
1884
16th to endNight
14%5%1321222458%
2112
November1st to 15thNight
10%323313346%56%
2246
16th to endNight
15%424323235%52%
2340
December1st to 15thNight
16%6%25%423345%45%
2340
16th to endNight
16%9%26%424345%39%
2625

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
43%36%17%22%5%
1562
16th to endDay
41%3420%22%6%
1797
February1st to 15thDay
42%37%22%18%6%
1752
16th to endDay
46%35%17%21%6%
1580
March1st to 15thDay
48%47%18%15%5%
1839
16th to endDay
42%5%8%22%20%1
2220
April1st to 15thDay
38%48%20%20%6%
2151
16th to endDay
36%410%22%24%2
2160
May1st to 15thDay
43%5%8%19%18%4
2160
16th to endDay
41%7%13%21%13%1
2435
June1st to 15thDay
38%8%13%21%16%
2469
16th to endDay
35%8%13%20%18%3
2520
July1st to 15thDay
42%9%16%20%7%3
2338
16th to endDay
43%10%18%18%8%
2228
August1st to 15thDay
40%10%14%20%11%3
2148
16th to endDay
43%9%14%19%9%2
2292
September1st to 15thDay
41%7%12%19%13%5%
2157
16th to endDay
36%5%8%21%19%9%
1894
October1st to 15thDay
31%48%19%24%11%
1744
16th to endDay
29%3319%33%11%
1760
November1st to 15thDay
30%26%19%30%10%
1612
16th to endDay
37%26%19%25%9%
1620
December1st to 15thDay
46%37%19%14%7%
1620
16th to endDay
47%39%19%16%4
1596
January1st to 15thNight
39%36%17%26%5%
2374
16th to endNight
45%35%17%21%7%
2424
February1st to 15thNight
41%26%20%20%8%
2112
16th to endNight
42%35%19%21%8%
1893
March1st to 15thNight
42%49%17%17%8%
2130
16th to endNight
37%38%23%22%4
2004
April1st to 15thNight
33%48%23%21%8%
1797
16th to endNight
31%410%23%24%6%
1800
May1st to 15thNight
34%5%12%20%21%5%
1788
16th to endNight
30%6%15%25%17%3
1684
June1st to 15thNight
30%6%16%24%20%2
1486
16th to endNight
24%7%17%25%21%4
1440
July1st to 15thNight
26%10%19%28%10%4
1391
16th to endNight
27%9%23%26%10%1
1674
August1st to 15thNight
28%9%21%23%12%4
1788
16th to endNight
34%10%15%23%12%3
1910
September1st to 15thNight
33%6%12%24%16%7%
1800
16th to endNight
28%6%9%21%24%9%
1894
October1st to 15thNight
27%48%21%24%14%
1884
16th to endNight
32%1314%31%16%
2112
November1st to 15thNight
29%37%19%27%13%
2246
16th to endNight
35%25%19%25%12%
2340
December1st to 15thNight
41%38%20%19%6%
2340
16th to endNight
47%37%16%18%6%
2625

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
20%16%40%17%32
90
16th to endDay
28%22%37%7%22
96
February1st to 15thDay
17%24%40%12%5%
90
16th to endDay
24%13%43%17%1
81
March1st to 15thDay
24%26%36%11%1
90
16th to endDay
16%13%33%25%10%
204
April1st to 15thDay
19%11%31%22%13%1
270
16th to endDay
17%8%26%27%16%2
270
May1st to 15thDay
17%8%23%33%12%5%
288
16th to endDay
12%425%26%18%12%
331
June1st to 15thDay
7%117%29%28%15%
444
16th to endDay
7%113%31%30%15%
495
July1st to 15thDay
7%19%31%34%15%
475
16th to endDay
7%17%20%37%26%
425
August1st to 15thDay
8%12%21%32%24%
313
16th to endDay
16%6%25%26%23%
332
September1st to 15thDay
10%312%21%35%16%
315
16th to endDay
11%9%29%33%14%
283
October1st to 15thDay
10%421%26%27%8%
184
16th to endDay
17%428%21%21%6%
96
November1st to 15thDay
17%337%25%14%1
90
16th to endDay
16%12%37%18%11%3
90
December1st to 15thDay
23%17%37%13%6%1
90
16th to endDay
21%16%40%14%6%
96
January1st to 15thNight
21%16%30%24%7%
900
16th to endNight
22%12%38%22%2
888
February1st to 15thNight
19%14%35%24%6%
704
16th to endNight
20%15%34%26%3
631
March1st to 15thNight
20%13%32%28%5%
690
16th to endNight
14%12%32%26%13%
576
April1st to 15thNight
12%11%34%26%13%1
539
16th to endNight
11%9%30%33%13%1
540
May1st to 15thNight
13%426%36%17%2
540
16th to endNight
6%120%36%30%4
563
June1st to 15thNight
5%9%38%35%10%
540
16th to endNight
4111%27%43%11%
540
July1st to 15thNight
27%30%43%14%
510
16th to endNight
45%24%45%19%
564
August1st to 15thNight
6%228%44%17%
539
16th to endNight
8%1426%45%13%
573
September1st to 15thNight
11%212%26%39%8%
540
16th to endNight
9%12%31%38%6%
680
October1st to 15thNight
10%317%33%30%4
660
16th to endNight
17%6%19%29%25%2
704
November1st to 15thNight
12%6%28%27%21%3
700
16th to endNight
18%8%29%26%15%1
720
December1st to 15thNight
20%10%29%30%9%
720
16th to endNight
22%13%31%24%7%
897
Page generated at 2017-09-24 08:15:51. Version ac04

Copyright 2017 A. Danko


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