Lone Wolf Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lone Wolf 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
38%
16019
18%
47068
11%
15976
45%
15976
24%
31129

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
21%
900
15%
2506
5%
895
30%
895
19%
1790
January16th to endNight
21%
960
14%
2594
5%
960
28%
960
17%
1932
February1st to 15thNight
22%
824
13%
2235
3%
824
29%
824
19%
1616
February16th to endNight
25%
631
19%
1893
7%
631
35%
631
19%
1314
March1st to 15thNight
28%
719
15%
2159
8%
719
33%
719
19%
1493
March16th to endNight
28%
576
14%
1996
9%
576
37%
576
17%
1395
April1st to 15thNight
29%
539
16%
1797
10%
539
40%
539
21%
1187
April16th to endNight
37%
540
18%
1788
13%
540
45%
540
21%
1188
May1st to 15thNight
35%
540
17%
1569
10%
540
42%
540
23%
1084
May16th to endNight
49%
563
19%
1497
11%
561
55%
561
31%
982
June1st to 15thNight
58%
540
17%
1440
11%
540
61%
540
35%
915
June16th to endNight
50%
540
18%
1440
10%
540
55%
540
34%
923
July1st to 15thNight
64%
510
17%
1360
12%
510
66%
510
38%
828
July16th to endNight
73%
564
24%
1417
18%
531
76%
531
42%
825
August1st to 15thNight
75%
539
22%
1623
22%
536
76%
536
40%
899
August16th to endNight
69%
573
22%
1910
23%
573
73%
573
34%
1078
September1st to 15thNight
63%
540
29%
1800
29%
540
68%
540
37%
958
September16th to endNight
59%
693
28%
1956
20%
693
64%
693
38%
1136
October1st to 15thNight
47%
684
28%
2007
19%
684
54%
684
34%
1186
October16th to endNight
31%
704
20%
2197
12%
704
41%
704
24%
1394
November1st to 15thNight
32%
700
24%
2276
15%
700
44%
700
26%
1368
November16th to endNight
28%
780
18%
2400
10%
780
37%
780
21%
1601
December1st to 15thNight
21%
900
13%
2520
5%
900
28%
900
17%
1875
December16th to endNight
16%
960
11%
2688
3%
960
23%
960
12%
2162

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
14%7%36%5%3445%7%38%
48140
Night
14%7%35%5%24446%41%
47237
Cloud CoverDay
13%8%36%5%3445%7%37%
48148
Night
13%7%36%5%24446%41%
47242
TransparencyDay
45%5%12%21%12%1
47826
Night
43%5%11%22%14%2
47069
SeeingDay
15%6%24%27%19%6%
6032
Night
16%8%29%30%13%1
16022

By Month

Percentage Cloud Cover NE (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
15%12%49%7%36%346%25%
1432
16th to endDay
14%15%6%9%6%34445%25%
1629
February1st to 15thDay
14%12%5%9%5%25%345%30%
1626
16th to endDay
13%11%48%6%34345%32%
1580
March1st to 15thDay
16%11%46%433446%33%
1802
16th to endDay
18%10%36%5%345%5%7%28%
2226
April1st to 15thDay
18%9%45%424335%37%
2151
16th to endDay
22%7%25%5%34446%33%
2172
May1st to 15thDay
21%7%36%5%25%45%7%31%
2381
16th to endDay
16%5%26%5%35%45%6%37%
2617
June1st to 15thDay
10%425%5%35%5%6%8%42%
2520
16th to endDay
10%425%7%36%5%5%8%40%
2520
July1st to 15thDay
8%3245%345%6%10%45%
2520
16th to endDay
6%415%5%35%6%6%10%43%
2655
August1st to 15thDay
8%424425%5%6%9%45%
2326
16th to endDay
10%324425%5%6%8%45%
2292
September1st to 15thDay
12%3243245%47%49%
2160
16th to endDay
8%5%245%2445%7%48%
1992
October1st to 15thDay
15%6%24323445%46%
1749
16th to endDay
17%8%25%5%24345%40%
1675
November1st to 15thDay
14%8%2431345%6%44%
1582
16th to endDay
18%12%35%333336%37%
1557
December1st to 15thDay
19%12%5%6%6%34445%27%
1440
16th to endDay
21%12%6%9%5%23435%25%
1536
January1st to 15thNight
14%9%47%6%34346%34%
2506
16th to endNight
12%13%6%7%6%34346%31%
2594
February1st to 15thNight
15%10%5%7%5%33346%34%
2233
16th to endNight
16%9%46%424345%37%
1893
March1st to 15thNight
16%10%35%5%33336%37%
2146
16th to endNight
17%8%36%6%25%5%47%33%
1996
April1st to 15thNight
16%9%35%324446%39%
1797
16th to endNight
19%6%345%2345%6%37%
1788
May1st to 15thNight
18%6%25%5%2336%8%35%
1569
16th to endNight
10%4245%26%6%5%8%43%
1496
June1st to 15thNight
11%32442445%6%49%
1440
16th to endNight
8%3246%345%6%8%44%
1440
July1st to 15thNight
7%31442446%9%50%
1440
16th to endNight
4313335%5%6%8%52%
1513
August1st to 15thNight
3315%425%45%9%54%
1632
16th to endNight
7%42342445%8%52%
1910
September1st to 15thNight
12%313323436%56%
1800
16th to endNight
7%3144335%6%8%51%
1956
October1st to 15thNight
10%5%14423237%51%
2007
16th to endNight
17%8%24322336%44%
2197
November1st to 15thNight
12%7%34423446%48%
2276
16th to endNight
16%7%36%424346%40%
2400
December1st to 15thNight
20%11%47%5%2434432%
2520
16th to endNight
23%14%5%8%6%2433424%
2688

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
15%12%5%9%7%45%346%25%
1432
16th to endDay
14%15%6%10%6%34335%25%
1629
February1st to 15thDay
14%12%5%10%5%15%34430%
1626
16th to endDay
13%11%48%7%25%35%5%31%
1580
March1st to 15thDay
16%12%46%42345%5%32%
1812
16th to endDay
17%10%37%6%35%5%5%7%28%
2224
April1st to 15thDay
17%10%46%423346%36%
2151
16th to endDay
21%7%26%5%335%46%33%
2172
May1st to 15thDay
18%9%36%5%245%5%8%30%
2381
16th to endDay
15%6%25%6%35%45%7%37%
2617
June1st to 15thDay
9%435%5%35%5%6%7%42%
2520
16th to endDay
9%5%25%6%35%5%6%9%39%
2520
July1st to 15thDay
7%4245%345%6%10%45%
2520
16th to endDay
6%4245%36%6%6%10%42%
2655
August1st to 15thDay
7%425%4345%6%10%45%
2326
16th to endDay
9%424425%5%6%8%45%
2292
September1st to 15thDay
12%42342345%7%48%
2160
16th to endDay
7%5%245%2445%7%48%
1992
October1st to 15thDay
14%7%24323436%46%
1749
16th to endDay
16%8%25%5%24436%39%
1675
November1st to 15thDay
14%7%34414447%43%
1582
16th to endDay
18%11%45%323335%37%
1557
December1st to 15thDay
19%12%5%6%6%35%445%27%
1440
16th to endDay
20%12%6%7%6%24345%25%
1536
January1st to 15thNight
15%9%47%6%3435%5%34%
2506
16th to endNight
12%12%6%9%6%34345%31%
2594
February1st to 15thNight
14%11%5%7%6%33336%34%
2226
16th to endNight
15%9%46%5%24345%37%
1893
March1st to 15thNight
16%10%45%424336%36%
2159
16th to endNight
16%8%46%6%3445%7%32%
1996
April1st to 15thNight
16%8%35%42435%6%39%
1797
16th to endNight
18%7%25%5%23347%37%
1788
May1st to 15thNight
18%6%36%5%2446%8%35%
1568
16th to endNight
10%425%5%35%5%6%8%42%
1496
June1st to 15thNight
10%424424446%49%
1440
16th to endNight
7%325%6%35%5%5%8%45%
1440
July1st to 15thNight
7%31442436%10%50%
1440
16th to endNight
4313435%5%6%9%52%
1513
August1st to 15thNight
32245%25%5%6%7%54%
1632
16th to endNight
7%42442445%7%51%
1910
September1st to 15thNight
11%313314336%56%
1800
16th to endNight
7%3144345%5%9%50%
1956
October1st to 15thNight
10%5%25%423246%52%
2007
16th to endNight
17%9%24422336%43%
2197
November1st to 15thNight
11%7%24423345%47%
2276
16th to endNight
16%7%35%5%24445%40%
2400
December1st to 15thNight
20%10%48%5%14335%31%
2520
16th to endNight
22%14%5%9%6%2333423%
2688

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
60%411%13%9%
1433
16th to endDay
60%5%11%15%7%
1629
February1st to 15thDay
56%5%13%17%5%1
1628
16th to endDay
53%5%13%21%6%1
1580
March1st to 15thDay
52%5%15%19%6%
1812
16th to endDay
53%7%13%19%5%
2226
April1st to 15thDay
50%311%22%11%
2151
16th to endDay
50%5%12%16%11%3
2172
May1st to 15thDay
50%5%12%22%7%
2381
16th to endDay
45%6%11%20%14%1
2621
June1st to 15thDay
37%7%12%25%15%1
2520
16th to endDay
39%8%12%20%17%2
2520
July1st to 15thDay
34%7%13%25%15%2
2371
16th to endDay
33%7%18%24%13%1
2488
August1st to 15thDay
31%7%15%27%16%1
2311
16th to endDay
33%7%13%26%16%3
2292
September1st to 15thDay
34%5%10%24%19%5%
2160
16th to endDay
34%5%10%27%19%2
1992
October1st to 15thDay
39%5%10%26%16%1
1749
16th to endDay
46%312%23%11%2
1675
November1st to 15thDay
40%411%25%15%2
1582
16th to endDay
50%312%23%8%
1557
December1st to 15thDay
60%312%17%6%
1440
16th to endDay
62%411%12%8%
1536
January1st to 15thNight
50%412%18%12%
2506
16th to endNight
55%414%17%8%
2594
February1st to 15thNight
51%412%20%9%1
2235
16th to endNight
49%411%23%9%
1893
March1st to 15thNight
49%412%20%9%1
2159
16th to endNight
51%5%12%20%8%1
1996
April1st to 15thNight
46%410%23%13%2
1797
16th to endNight
45%5%10%21%11%5%
1788
May1st to 15thNight
46%5%11%22%13%
1569
16th to endNight
36%8%13%22%16%2
1498
June1st to 15thNight
34%6%10%25%19%3
1440
16th to endNight
34%7%13%22%18%3
1440
July1st to 15thNight
30%6%13%29%17%3
1360
16th to endNight
26%6%13%29%19%3
1417
August1st to 15thNight
26%6%14%29%19%3
1623
16th to endNight
30%7%10%27%19%4
1910
September1st to 15thNight
30%29%26%25%5%
1800
16th to endNight
29%5%12%28%21%3
1956
October1st to 15thNight
33%49%26%22%2
2007
16th to endNight
42%49%25%16%1
2197
November1st to 15thNight
38%49%24%17%5%
2276
16th to endNight
45%411%24%13%
2400
December1st to 15thNight
56%311%19%8%
2520
16th to endNight
65%38%14%6%
2688

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
28%18%26%20%5%
90
16th to endDay
16%15%37%20%9%
96
February1st to 15thDay
24%10%43%15%6%
90
16th to endDay
13%16%34%23%12%
81
March1st to 15thDay
31%21%27%17%2
90
16th to endDay
30%10%28%17%10%2
210
April1st to 15thDay
22%11%29%25%10%
270
16th to endDay
23%8%24%25%13%3
270
May1st to 15thDay
22%9%29%24%11%2
338
16th to endDay
18%8%29%24%14%5%
517
June1st to 15thDay
10%226%33%21%4
495
16th to endDay
11%6%30%28%18%4
495
July1st to 15thDay
10%322%30%22%10%
475
16th to endDay
7%217%31%27%12%
515
August1st to 15thDay
8%113%32%28%14%
427
16th to endDay
9%114%30%31%12%
332
September1st to 15thDay
10%314%30%32%9%
315
16th to endDay
7%418%27%32%9%
314
October1st to 15thDay
16%8%20%30%21%4
150
16th to endDay
23%440%25%6%
96
November1st to 15thDay
5%8%28%30%20%6%
90
16th to endDay
38%11%24%17%7%
90
December1st to 15thDay
20%17%28%28%4
90
16th to endDay
26%20%43%7%2
96
January1st to 15thNight
18%13%39%21%6%
900
16th to endNight
17%13%37%28%3
960
February1st to 15thNight
19%11%38%25%4
827
16th to endNight
21%11%36%24%5%
631
March1st to 15thNight
21%12%33%25%6%
719
16th to endNight
19%8%36%26%7%1
576
April1st to 15thNight
19%13%33%26%6%
539
16th to endNight
20%7%29%30%10%
540
May1st to 15thNight
21%6%32%30%8%1
540
16th to endNight
10%328%40%14%1
563
June1st to 15thNight
12%222%48%13%
540
16th to endNight
9%128%40%19%1
540
July1st to 15thNight
9%117%40%29%2
510
16th to endNight
4112%46%31%3
564
August1st to 15thNight
4110%44%32%6%
539
16th to endNight
8%114%37%33%3
573
September1st to 15thNight
12%314%36%29%4
540
16th to endNight
8%420%36%27%3
693
October1st to 15thNight
13%5%27%31%20%2
684
16th to endNight
22%10%31%26%8%
704
November1st to 15thNight
16%10%36%26%10%
700
16th to endNight
20%12%33%24%8%
780
December1st to 15thNight
24%11%34%24%5%
900
16th to endNight
29%11%33%22%3
960
Page generated at 2017-10-07 13:07:48. Version ac04

Copyright 2017 A. Danko


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