Pattony Pioneer Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Pattony Pioneer Observatory 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
52%
15948
27%
46941
18%
15906
61%
15906
40%
25958

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
52%
899
31%
2506
21%
895
61%
895
47%
1323
January16th to endNight
50%
820
33%
2548
24%
820
61%
820
41%
1355
February1st to 15thNight
45%
699
24%
2223
16%
698
55%
698
34%
1248
February16th to endNight
38%
632
34%
1894
15%
632
57%
632
38%
1037
March1st to 15thNight
45%
720
28%
2136
14%
720
58%
720
42%
1164
March16th to endNight
43%
665
28%
2009
14%
665
57%
665
39%
1120
April1st to 15thNight
35%
539
24%
1798
13%
539
50%
539
32%
994
April16th to endNight
40%
540
21%
1800
16%
540
50%
540
28%
1067
May1st to 15thNight
46%
540
19%
1625
14%
540
53%
540
27%
1034
May16th to endNight
46%
562
17%
1498
10%
561
53%
561
35%
924
June1st to 15thNight
58%
540
21%
1440
13%
540
64%
540
47%
778
June16th to endNight
66%
540
25%
1440
19%
540
70%
540
49%
769
July1st to 15thNight
65%
510
17%
1360
13%
510
68%
510
34%
845
July16th to endNight
67%
564
23%
1427
17%
531
70%
531
38%
857
August1st to 15thNight
65%
539
17%
1693
16%
536
68%
536
32%
977
August16th to endNight
66%
573
26%
1910
26%
573
72%
573
39%
1005
September1st to 15thNight
64%
540
27%
1800
27%
540
71%
540
38%
960
September16th to endNight
64%
519
34%
1881
31%
519
73%
519
45%
873
October1st to 15thNight
51%
627
29%
1947
19%
627
60%
627
39%
1057
October16th to endNight
61%
745
36%
2153
21%
745
70%
745
51%
1087
November1st to 15thNight
56%
875
34%
2275
19%
875
63%
875
51%
1223
November16th to endNight
55%
900
35%
2370
20%
900
62%
900
50%
1280
December1st to 15thNight
49%
900
27%
2520
15%
900
58%
900
43%
1391
December16th to endNight
43%
960
27%
2688
15%
960
54%
960
36%
1590

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%5%2442446%8%52%
48000
Night
45%2432445%7%55%
47115
Cloud CoverDay
5%42432445%8%52%
47998
Night
5%5%2432345%7%55%
47115
TransparencyDay
28%5%10%24%22%8%
47676
Night
27%5%11%26%22%7%
46941
SeeingDay
9%8%26%29%19%7%
5873
Night
7%429%40%16%1
15955

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
26%24313347%61%
1432
16th to endDay
25%24322347%61%
1686
February1st to 15thDay
17%36%424346%54%
1639
16th to endDay
27%2332335%7%56%
1580
March1st to 15thDay
35%34424347%54%
1821
16th to endDay
6%7%234245%6%8%49%
2214
April1st to 15thDay
8%6%1432445%7%50%
2150
16th to endDay
10%7%24325%46%6%45%
2160
May1st to 15thDay
9%7%245%3446%8%41%
2321
16th to endDay
8%324436%5%6%8%44%
2616
June1st to 15thDay
6%4134245%7%8%50%
2520
16th to endDay
32133345%7%9%54%
2520
July1st to 15thDay
7%313435%5%8%10%45%
2520
16th to endDay
44145%36%6%6%10%45%
2641
August1st to 15thDay
44245%36%6%6%9%46%
2256
16th to endDay
5%2144345%7%9%52%
2292
September1st to 15thDay
7%31332446%8%53%
2160
16th to endDay
4213323346%64%
1937
October1st to 15thDay
6%313313347%60%
1681
16th to endDay
5%423212245%66%
1707
November1st to 15thDay
142342445%6%60%
1583
16th to endDay
25%23313337%62%
1588
December1st to 15thDay
27%25%32445%7%55%
1440
16th to endDay
35%46%323447%53%
1536
January1st to 15thNight
1424413347%62%
2506
16th to endNight
25%25%423235%60%
2548
February1st to 15thNight
28%35%324348%52%
2213
16th to endNight
18%25%423346%57%
1894
March1st to 15thNight
46%2332346%6%56%
2136
16th to endNight
5%7%2332345%7%55%
2009
April1st to 15thNight
5%8%14424347%53%
1798
16th to endNight
13%8%24313346%48%
1800
May1st to 15thNight
13%6%2342446%8%43%
1624
16th to endNight
7%5%2442445%8%50%
1497
June1st to 15thNight
431322345%11%57%
1440
16th to endNight
22123245%7%8%59%
1440
July1st to 15thNight
6%324436%5%8%8%47%
1440
16th to endNight
5%314437%6%7%11%45%
1524
August1st to 15thNight
4424436%5%6%8%47%
1702
16th to endNight
5%3133245%7%9%53%
1910
September1st to 15thNight
7%42332437%8%53%
1800
16th to endNight
4313313345%65%
1881
October1st to 15thNight
6%5%13323445%58%
1947
16th to endNight
4413212348%62%
2153
November1st to 15thNight
2314223347%63%
2275
16th to endNight
35%23313337%62%
2370
December1st to 15thNight
26%35%32335%7%57%
2520
16th to endNight
28%45%424446%52%
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
26%25%213338%60%
1432
16th to endDay
25%24323337%61%
1686
February1st to 15thDay
17%36%434336%54%
1639
16th to endDay
27%2442345%6%56%
1580
March1st to 15thDay
45%25%424347%55%
1821
16th to endDay
6%7%2442445%8%49%
2212
April1st to 15thDay
7%6%1441346%8%51%
2150
16th to endDay
10%7%23425%5%6%6%45%
2160
May1st to 15thDay
9%7%25%4245%5%8%42%
2321
16th to endDay
8%424435%6%6%9%45%
2616
June1st to 15thDay
6%3143245%7%9%49%
2520
16th to endDay
3213335%5%7%10%55%
2520
July1st to 15thDay
7%313435%6%7%10%46%
2520
16th to endDay
43145%37%6%6%10%46%
2641
August1st to 15thDay
5%324435%6%7%10%46%
2256
16th to endDay
4213435%5%6%9%52%
2292
September1st to 15thDay
7%3134235%5%8%55%
2160
16th to endDay
4212223246%65%
1937
October1st to 15thDay
6%313223347%60%
1681
16th to endDay
5%413212245%65%
1707
November1st to 15thDay
25%23323447%59%
1583
16th to endDay
35%23312347%62%
1588
December1st to 15thDay
26%25%32345%6%55%
1440
16th to endDay
45%37%323448%52%
1536
January1st to 15thNight
2424422447%61%
2506
16th to endNight
26%25%5%23235%60%
2548
February1st to 15thNight
28%35%424348%52%
2213
16th to endNight
28%34423346%56%
1894
March1st to 15thNight
46%2332345%7%56%
2136
16th to endNight
6%6%2332335%8%54%
2009
April1st to 15thNight
6%7%24423347%52%
1798
16th to endNight
14%7%24323345%47%
1800
May1st to 15thNight
13%5%144245%6%7%44%
1624
16th to endNight
7%425%4235%6%7%50%
1497
June1st to 15thNight
421232446%11%55%
1440
16th to endNight
22133245%6%9%59%
1440
July1st to 15thNight
5%324436%6%8%8%46%
1440
16th to endNight
5%224427%5%8%11%45%
1524
August1st to 15thNight
44145%36%5%7%8%47%
1702
16th to endNight
5%3232145%7%9%53%
1910
September1st to 15thNight
7%41342337%8%53%
1800
16th to endNight
5%212323445%65%
1881
October1st to 15thNight
7%5%13323445%58%
1947
16th to endNight
5%41221335%7%62%
2153
November1st to 15thNight
2313323346%63%
2275
16th to endNight
35%24213237%62%
2370
December1st to 15thNight
26%34323347%56%
2520
16th to endNight
29%35%423446%51%
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
22%410%31%25%5%
1433
16th to endDay
23%39%32%23%8%
1686
February1st to 15thDay
30%410%34%15%4
1640
16th to endDay
26%46%29%25%7%
1580
March1st to 15thDay
28%49%24%24%8%
1821
16th to endDay
31%5%10%25%20%5%
2214
April1st to 15thDay
31%411%25%20%7%
2150
16th to endDay
36%6%11%23%17%4
2160
May1st to 15thDay
38%6%12%23%15%2
2321
16th to endDay
33%8%14%24%12%6%
2620
June1st to 15thDay
28%6%13%21%18%11%
2520
16th to endDay
21%5%10%21%28%11%
2520
July1st to 15thDay
31%7%12%20%16%11%
2371
16th to endDay
31%7%12%25%16%6%
2475
August1st to 15thDay
30%8%14%20%16%9%
2241
16th to endDay
26%6%10%24%25%7%
2292
September1st to 15thDay
25%5%10%22%21%14%
2160
16th to endDay
20%37%22%36%9%
1937
October1st to 15thDay
23%49%23%29%9%
1681
16th to endDay
20%27%27%30%10%
1707
November1st to 15thDay
22%49%24%24%14%
1583
16th to endDay
22%35%24%32%12%
1588
December1st to 15thDay
27%411%31%20%4
1440
16th to endDay
30%413%24%19%7%
1536
January1st to 15thNight
22%311%30%25%5%
2506
16th to endNight
26%47%27%23%9%
2548
February1st to 15thNight
32%311%31%17%4
2223
16th to endNight
28%35%31%23%8%
1894
March1st to 15thNight
26%39%27%26%7%
2136
16th to endNight
28%410%25%25%5%
2009
April1st to 15thNight
30%411%26%19%7%
1798
16th to endNight
37%411%25%16%4
1800
May1st to 15thNight
37%8%14%22%13%4
1625
16th to endNight
31%8%20%22%11%6%
1498
June1st to 15thNight
22%5%19%26%14%11%
1440
16th to endNight
19%7%12%25%26%9%
1440
July1st to 15thNight
31%8%15%20%14%9%
1360
16th to endNight
27%9%16%24%19%3
1427
August1st to 15thNight
31%7%17%22%14%7%
1693
16th to endNight
24%7%12%29%20%6%
1910
September1st to 15thNight
27%5%12%23%20%10%
1800
16th to endNight
20%49%27%30%7%
1881
October1st to 15thNight
26%5%12%20%25%9%
1947
16th to endNight
20%38%27%29%10%
2153
November1st to 15thNight
20%37%25%26%15%
2275
16th to endNight
23%27%24%31%10%
2370
December1st to 15thNight
26%412%30%20%5%
2520
16th to endNight
31%412%25%21%4
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
12%7%13%37%24%4
90
16th to endDay
6%6%31%37%17%1
96
February1st to 15thDay
28%48%33%6%
90
16th to endDay
412%37%23%22%
81
March1st to 15thDay
212%36%36%9%2
111
16th to endDay
15%19%36%20%6%1
288
April1st to 15thDay
13%18%34%21%8%2
269
16th to endDay
20%23%29%19%6%1
270
May1st to 15thDay
14%9%29%28%12%3
435
16th to endDay
14%9%24%26%17%6%
517
June1st to 15thDay
10%6%24%29%20%9%
495
16th to endDay
5%424%32%26%7%
495
July1st to 15thDay
10%315%29%29%11%
475
16th to endDay
7%213%29%34%12%
500
August1st to 15thDay
8%422%31%23%9%
315
16th to endDay
7%124%37%21%8%
332
September1st to 15thDay
7%5%31%28%16%10%
315
16th to endDay
7%6%27%23%19%15%
147
October1st to 15thDay
4225%24%27%15%
90
16th to endDay
7%426%30%25%7%
96
November1st to 15thDay
2416%41%26%8%
90
16th to endDay
8%8%40%26%15%
90
December1st to 15thDay
5%12%44%27%10%
90
16th to endDay
47%35%41%8%3
96
January1st to 15thNight
4433%42%13%2
900
16th to endNight
3433%45%10%1
820
February1st to 15thNight
5%5%36%42%9%
704
16th to endNight
46%42%37%7%
632
March1st to 15thNight
6%5%37%39%10%1
720
16th to endNight
8%7%35%38%8%
665
April1st to 15thNight
10%10%40%31%7%
539
16th to endNight
17%7%31%32%10%
540
May1st to 15thNight
15%5%27%39%11%
540
16th to endNight
10%330%35%17%1
563
June1st to 15thNight
4328%43%18%1
540
16th to endNight
3121%47%23%1
540
July1st to 15thNight
7%114%40%31%4
510
16th to endNight
6%115%39%35%2
564
August1st to 15thNight
6%115%43%29%2
539
16th to endNight
6%118%43%26%4
573
September1st to 15thNight
8%118%43%23%3
540
16th to endNight
6%121%44%23%3
519
October1st to 15thNight
9%429%37%15%3
627
16th to endNight
7%223%39%21%4
745
November1st to 15thNight
45%29%42%16%1
875
16th to endNight
6%5%29%41%15%2
900
December1st to 15thNight
5%434%43%10%1
900
16th to endNight
6%6%35%38%10%1
960
Page generated at 2017-09-25 07:02:22. Version ac04

Copyright 2017 A. Danko


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