Conner Preserve
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Conner Preserve clear sky chart from 2005-11-05 to

2017-09-12
.

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
61%
15836
21%
46893
18%
15795
66%
15795
31%
28808

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
47%
718
20%
2327
16%
716
54%
716
26%
1424
January16th to endNight
45%
768
24%
2403
18%
768
53%
768
27%
1491
February1st to 15thNight
47%
701
26%
2103
19%
698
55%
698
34%
1233
February16th to endNight
48%
631
25%
1865
16%
631
57%
631
32%
1118
March1st to 15thNight
49%
720
29%
1980
17%
720
59%
720
39%
1148
March16th to endNight
55%
768
27%
2112
21%
768
60%
768
40%
1217
April1st to 15thNight
61%
718
25%
1976
19%
718
65%
718
44%
1093
April16th to endNight
62%
696
27%
1854
19%
696
67%
696
43%
1068
May1st to 15thNight
78%
539
26%
1619
22%
539
80%
539
45%
865
May16th to endNight
76%
561
24%
1682
20%
561
78%
561
39%
957
June1st to 15thNight
72%
540
12%
1620
12%
540
72%
540
26%
1080
June16th to endNight
74%
540
10%
1620
9%
540
74%
540
25%
1103
July1st to 15thNight
74%
510
6%
1530
6%
510
74%
510
22%
1107
July16th to endNight
78%
564
7%
1595
7%
531
79%
531
24%
1107
August1st to 15thNight
75%
539
5%
1663
6%
536
75%
536
25%
1132
August16th to endNight
70%
687
9%
2024
10%
687
70%
687
22%
1410
September1st to 15thNight
65%
707
8%
1944
8%
707
65%
707
21%
1400
September16th to endNight
65%
657
14%
1815
13%
657
66%
657
23%
1269
October1st to 15thNight
71%
660
27%
1847
27%
660
73%
660
35%
1115
October16th to endNight
60%
704
29%
2112
28%
704
65%
704
35%
1223
November1st to 15thNight
64%
700
31%
2101
28%
700
70%
700
41%
1137
November16th to endNight
54%
720
29%
2265
24%
720
63%
720
34%
1283
December1st to 15thNight
53%
720
27%
2340
25%
720
60%
720
31%
1373
December16th to endNight
55%
768
24%
2496
23%
768
60%
768
30%
1455

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
8%5%25%6%36%6%6%8%38%
47741
Night
7%425%5%35%5%6%9%44%
47102
TransparencyDay
41%6%14%17%14%5%
47442
Night
34%7%16%20%15%5%
46905
SeeingDay
9%211%20%27%28%
5700
Night
9%315%33%28%9%
15844

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
12%5%25%43446%10%40%
1611
16th to endDay
10%5%245%34447%46%
1818
February1st to 15thDay
14%425%423446%46%
1750
16th to endDay
8%425%43435%7%50%
1607
March1st to 15thDay
6%32442445%8%52%
1980
16th to endDay
8%4245%35%35%6%50%
2111
April1st to 15thDay
7%325%5%35%5%6%7%47%
1972
16th to endDay
6%314436%5%5%7%49%
2110
May1st to 15thDay
6%3244245%5%8%52%
2331
16th to endDay
7%425%5%37%6%6%8%40%
2431
June1st to 15thDay
11%7%27%8%47%6%7%10%26%
2340
16th to endDay
8%7%36%8%49%7%8%9%25%
2340
July1st to 15thDay
9%6%37%8%5%9%8%9%10%21%
2340
16th to endDay
8%6%37%9%5%9%8%8%11%20%
2465
August1st to 15thDay
9%5%37%9%6%8%8%9%10%20%
2282
16th to endDay
11%6%38%8%5%9%7%7%9%23%
2163
September1st to 15thDay
10%6%38%9%6%7%6%8%9%22%
1936
16th to endDay
10%7%47%9%47%7%7%9%23%
1815
October1st to 15thDay
8%5%25%7%47%6%5%7%40%
1782
16th to endDay
8%5%24434447%48%
1760
November1st to 15thDay
6%424425%447%53%
1757
16th to endDay
8%425%425%5%48%47%
1692
December1st to 15thDay
9%6%35%5%36%45%8%42%
1620
16th to endDay
7%4245%35%5%6%8%46%
1728
January1st to 15thNight
11%6%26%4345%6%9%40%
2327
16th to endNight
13%5%25%425%45%8%41%
2403
February1st to 15thNight
11%6%2442245%6%50%
2103
16th to endNight
8%5%35%433348%48%
1865
March1st to 15thNight
6%424424447%54%
1980
16th to endNight
6%42442445%7%53%
2112
April1st to 15thNight
5%31332346%10%54%
1976
16th to endNight
6%314434447%56%
1854
May1st to 15thNight
421332345%9%57%
1619
16th to endNight
42135%25%5%6%9%51%
1682
June1st to 15thNight
9%435%5%46%6%6%11%37%
1620
16th to endNight
6%426%5%37%6%8%12%34%
1620
July1st to 15thNight
5%426%7%38%7%10%14%31%
1620
16th to endNight
4425%7%5%7%7%11%13%29%
1703
August1st to 15thNight
45%25%6%5%7%6%9%14%32%
1674
16th to endNight
7%5%35%6%36%7%9%11%33%
2024
September1st to 15thNight
8%5%36%7%46%6%9%12%29%
1944
16th to endNight
9%5%36%6%46%6%8%11%30%
1815
October1st to 15thNight
6%5%235%345%7%7%48%
1847
16th to endNight
9%6%2432335%7%51%
2112
November1st to 15thNight
6%32432445%7%54%
2101
16th to endNight
7%4245%245%48%50%
2265
December1st to 15thNight
9%434425%447%48%
2340
16th to endNight
7%5%245%25%5%6%9%44%
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
39%310%20%20%5%
1612
16th to endDay
37%38%17%24%9%
1818
February1st to 15thDay
38%46%15%20%15%
1752
16th to endDay
33%410%17%22%11%
1607
March1st to 15thDay
28%311%24%22%8%
1980
16th to endDay
34%210%21%20%9%
2112
April1st to 15thDay
33%5%11%19%22%8%
1972
16th to endDay
32%49%21%25%7%
2110
May1st to 15thDay
29%412%25%19%8%
2331
16th to endDay
38%5%14%21%16%2
2435
June1st to 15thDay
50%7%19%18%4
2340
16th to endDay
50%9%22%13%3
2340
July1st to 15thDay
53%12%25%8%1
2201
16th to endDay
51%13%22%10%1
2310
August1st to 15thDay
52%11%28%7%
2269
16th to endDay
54%11%19%13%
2163
September1st to 15thDay
54%10%20%10%3
1936
16th to endDay
50%10%14%15%6%2
1815
October1st to 15thDay
40%6%8%17%16%10%
1782
16th to endDay
34%48%17%21%13%
1760
November1st to 15thDay
30%38%25%22%10%
1757
16th to endDay
34%48%20%18%13%
1692
December1st to 15thDay
39%411%21%16%6%
1620
16th to endDay
33%5%11%22%18%7%
1728
January1st to 15thNight
39%412%20%17%5%
2327
16th to endNight
39%48%18%20%8%
2403
February1st to 15thNight
33%48%17%23%13%
2112
16th to endNight
35%412%18%22%7%
1865
March1st to 15thNight
29%411%27%19%7%
1980
16th to endNight
28%5%11%26%20%8%
2112
April1st to 15thNight
25%415%26%22%5%
1976
16th to endNight
27%413%25%22%6%
1854
May1st to 15thNight
23%5%16%28%19%7%
1620
16th to endNight
26%7%19%24%18%2
1684
June1st to 15thNight
38%10%24%19%6%
1620
16th to endNight
37%13%25%19%4
1620
July1st to 15thNight
38%16%31%10%1
1530
16th to endNight
38%14%33%12%1
1595
August1st to 15thNight
36%14%37%11%
1663
16th to endNight
40%13%27%16%1
2024
September1st to 15thNight
43%12%26%12%3
1944
16th to endNight
42%10%20%18%5%1
1815
October1st to 15thNight
31%7%11%21%19%8%
1847
16th to endNight
32%48%18%25%10%
2112
November1st to 15thNight
27%310%23%24%9%
2101
16th to endNight
32%39%22%18%12%
2265
December1st to 15thNight
35%410%27%16%5%
2340
16th to endNight
34%5%13%22%15%8%
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
13%8%33%23%17%3
90
16th to endDay
15%15%30%25%12%1
96
February1st to 15thDay
11%14%23%22%22%6%
90
16th to endDay
7%10%33%31%17%
108
March1st to 15thDay
7%6%31%31%20%2
270
16th to endDay
7%424%29%28%5%
288
April1st to 15thDay
9%419%31%28%7%
270
16th to endDay
6%111%31%34%14%
270
May1st to 15thDay
5%213%26%31%20%
288
16th to endDay
7%25%19%28%37%
331
June1st to 15thDay
16%229%25%42%
315
16th to endDay
7%18%29%52%
315
July1st to 15thDay
7%420%66%
305
16th to endDay
13%118%21%53%
326
August1st to 15thDay
11%17%21%58%
313
16th to endDay
8%129%27%51%
332
September1st to 15thDay
14%139%31%40%
299
16th to endDay
14%1111%36%34%
254
October1st to 15thDay
8%27%28%39%13%
255
16th to endDay
9%217%31%27%9%
272
November1st to 15thDay
7%113%33%32%11%
265
16th to endDay
6%121%41%22%6%
162
December1st to 15thDay
6%342%33%14%
90
16th to endDay
5%414%44%28%3
96
January1st to 15thNight
12%6%23%38%17%
720
16th to endNight
15%6%27%36%14%
768
February1st to 15thNight
14%5%27%37%14%
704
16th to endNight
10%5%26%45%11%
631
March1st to 15thNight
8%431%41%13%
720
16th to endNight
7%5%23%44%17%1
768
April1st to 15thNight
6%322%44%20%1
718
16th to endNight
8%319%44%23%
696
May1st to 15thNight
419%47%32%3
540
16th to endNight
48%37%39%8%
563
June1st to 15thNight
10%1320%47%16%
540
16th to endNight
6%1211%46%31%
540
July1st to 15thNight
6%16%46%38%
510
16th to endNight
5%15%46%39%
564
August1st to 15thNight
6%15%49%36%
539
16th to endNight
9%2214%42%28%
687
September1st to 15thNight
11%1418%43%21%
707
16th to endNight
10%1328%43%12%
657
October1st to 15thNight
9%17%40%35%6%
660
16th to endNight
10%316%35%30%2
704
November1st to 15thNight
6%218%46%22%3
700
16th to endNight
8%324%42%19%1
720
December1st to 15thNight
10%423%39%20%
720
16th to endNight
8%421%40%22%1
768
Page generated at 2017-09-13 07:39:13. Version ac04

Copyright 2017 A. Danko


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