Camp Perry
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Camp Perry clear sky chart from 2005-11-05 to 2017-09-21.

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%
15211
24%
47026
18%
15168
59%
15168
31%
28107

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
30%
720
26%
2279
12%
716
46%
716
26%
1378
January16th to endNight
30%
768
26%
2304
13%
768
42%
768
24%
1495
February1st to 15thNight
32%
704
26%
2112
11%
701
45%
701
28%
1283
February16th to endNight
31%
631
26%
1893
12%
631
43%
631
28%
1167
March1st to 15thNight
33%
720
22%
2160
12%
720
41%
720
28%
1314
March16th to endNight
43%
670
26%
2029
15%
670
53%
670
32%
1188
April1st to 15thNight
45%
539
25%
1797
18%
539
56%
539
31%
1012
April16th to endNight
52%
540
28%
1800
23%
540
63%
540
36%
959
May1st to 15thNight
55%
539
23%
1692
17%
539
63%
539
32%
996
May16th to endNight
70%
561
25%
1682
21%
561
73%
561
36%
973
June1st to 15thNight
71%
540
15%
1620
14%
540
72%
540
31%
1023
June16th to endNight
77%
540
19%
1620
19%
540
77%
540
35%
960
July1st to 15thNight
78%
510
14%
1530
13%
510
79%
510
32%
947
July16th to endNight
75%
564
14%
1693
15%
531
77%
531
29%
1064
August1st to 15thNight
77%
539
17%
1788
20%
536
78%
536
29%
1087
August16th to endNight
71%
573
19%
1910
24%
573
71%
573
23%
1256
September1st to 15thNight
63%
600
22%
1860
22%
600
64%
600
27%
1159
September16th to endNight
67%
681
29%
1881
23%
681
70%
681
38%
1123
October1st to 15thNight
62%
660
33%
1815
26%
660
67%
660
43%
1017
October16th to endNight
56%
704
35%
2109
28%
704
64%
704
40%
1138
November1st to 15thNight
53%
700
31%
2276
26%
700
64%
700
38%
1194
November16th to endNight
44%
720
29%
2340
20%
720
56%
720
32%
1304
December1st to 15thNight
40%
720
24%
2340
18%
720
50%
720
28%
1406
December16th to endNight
32%
768
20%
2496
15%
768
39%
768
20%
1664

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
12%5%25%5%35%5%5%7%42%
47818
Night
11%42442445%8%46%
47235
TransparencyDay
39%5%10%19%18%5%
47529
Night
35%410%19%21%8%
47028
SeeingDay
13%5%16%24%24%15%
5139
Night
13%6%21%29%23%5%
15214

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
19%5%3442343444%
1656
16th to endDay
17%5%3332444446%
1920
February1st to 15thDay
15%5%25%433447%43%
1750
16th to endDay
18%5%36%5%23335%42%
1580
March1st to 15thDay
16%6%25%424336%43%
1800
16th to endDay
13%5%25%435%346%44%
2203
April1st to 15thDay
12%5%2442445%7%45%
2151
16th to endDay
8%4145%25%447%49%
2160
May1st to 15thDay
10%5%25%5%245%6%7%43%
2256
16th to endDay
7%425%6%36%5%7%7%42%
2431
June1st to 15thDay
8%426%7%46%6%7%11%34%
2340
16th to endDay
7%3245%36%7%7%11%40%
2340
July1st to 15thDay
9%5%26%7%47%7%7%10%30%
2340
16th to endDay
7%425%7%49%7%9%10%30%
2355
August1st to 15thDay
7%426%7%5%6%7%9%12%32%
2160
16th to endDay
11%5%26%8%47%6%7%9%30%
2292
September1st to 15thDay
10%6%25%6%5%5%5%6%6%38%
2087
16th to endDay
12%426%5%3445%6%45%
1872
October1st to 15thDay
8%42443335%6%52%
1815
16th to endDay
10%324423235%57%
1760
November1st to 15thDay
13%313413345%56%
1582
16th to endDay
14%414413345%52%
1620
December1st to 15thDay
16%6%26%323446%42%
1620
16th to endDay
23%8%36%423235%36%
1728
January1st to 15thNight
16%5%25%313345%48%
2279
16th to endNight
18%6%25%5%32335%42%
2304
February1st to 15thNight
14%5%24333346%47%
2103
16th to endNight
16%5%24422335%49%
1893
March1st to 15thNight
16%424323447%46%
2160
16th to endNight
12%32442435%6%50%
2029
April1st to 15thNight
10%314425%5%5%9%47%
1797
16th to endNight
9%31332435%7%54%
1800
May1st to 15thNight
10%42442445%9%47%
1691
16th to endNight
4323436%6%7%9%48%
1682
June1st to 15thNight
5%3246%46%6%8%12%38%
1620
16th to endNight
43345%35%7%7%12%43%
1620
July1st to 15thNight
7%324437%5%8%12%39%
1620
16th to endNight
5%4245%38%7%8%11%38%
1810
August1st to 15thNight
6%3145%36%7%8%14%38%
1800
16th to endNight
7%5%36%6%5%6%6%6%9%37%
1910
September1st to 15thNight
9%6%35%5%3445%9%42%
1860
16th to endNight
8%32442446%6%51%
1881
October1st to 15thNight
9%314223348%55%
1815
16th to endNight
11%313213235%60%
2109
November1st to 15thNight
10%323322346%56%
2276
16th to endNight
12%424423345%52%
2340
December1st to 15thNight
14%6%34423446%46%
2340
16th to endNight
20%7%35%5%24345%37%
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
43%26%15%24%7%
1657
16th to endDay
40%35%18%23%8%
1920
February1st to 15thDay
40%25%22%20%7%
1752
16th to endDay
45%25%17%23%7%
1580
March1st to 15thDay
43%38%18%20%6%
1800
16th to endDay
40%310%20%21%4
2204
April1st to 15thDay
37%38%21%21%7%
2151
16th to endDay
32%49%22%25%4
2160
May1st to 15thDay
38%412%16%22%5%
2256
16th to endDay
36%6%14%23%16%3
2435
June1st to 15thDay
40%6%14%24%11%2
2340
16th to endDay
32%8%16%23%16%3
2340
July1st to 15thDay
42%9%17%20%7%1
2201
16th to endDay
41%10%20%19%7%
2209
August1st to 15thDay
38%8%19%18%11%2
2148
16th to endDay
45%8%14%17%10%3
2292
September1st to 15thDay
43%5%12%17%14%6%
2087
16th to endDay
39%48%19%19%7%
1872
October1st to 15thDay
31%38%17%26%12%
1815
16th to endDay
31%2416%31%15%
1760
November1st to 15thDay
31%25%19%28%11%
1582
16th to endDay
34%27%16%26%11%
1620
December1st to 15thDay
42%38%21%17%6%
1620
16th to endDay
51%27%18%15%5%
1728
January1st to 15thNight
38%26%16%27%7%
2279
16th to endNight
44%2316%23%9%
2304
February1st to 15thNight
39%16%18%22%11%
2112
16th to endNight
38%3417%24%10%
1893
March1st to 15thNight
38%29%18%22%8%
2160
16th to endNight
34%38%23%24%6%
2029
April1st to 15thNight
33%39%19%23%10%
1797
16th to endNight
28%49%22%26%8%
1800
May1st to 15thNight
34%411%17%22%8%
1692
16th to endNight
29%6%13%26%17%5%
1684
June1st to 15thNight
35%8%18%20%15%2
1620
16th to endNight
30%7%19%21%17%4
1620
July1st to 15thNight
31%10%23%23%9%2
1530
16th to endNight
34%9%25%21%7%
1693
August1st to 15thNight
32%10%17%24%10%4
1788
16th to endNight
40%9%15%17%13%3
1910
September1st to 15thNight
39%5%13%20%13%6%
1860
16th to endNight
30%5%11%20%23%8%
1881
October1st to 15thNight
26%48%18%25%17%
1815
16th to endNight
28%2411%32%20%
2109
November1st to 15thNight
28%25%17%28%17%
2276
16th to endNight
33%25%18%23%15%
2340
December1st to 15thNight
38%39%19%22%6%
2340
16th to endNight
49%27%17%18%5%
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
22%13%37%14%10%2
90
16th to endDay
20%23%38%13%21
96
February1st to 15thDay
16%24%31%25%2
90
16th to endDay
29%9%33%24%2
81
March1st to 15thDay
22%24%38%11%21
90
16th to endDay
19%8%26%26%19%
273
April1st to 15thDay
17%11%25%23%18%3
270
16th to endDay
8%6%25%33%21%4
270
May1st to 15thDay
12%8%21%27%21%8%
288
16th to endDay
9%417%32%19%16%
331
June1st to 15thDay
11%110%21%27%27%
315
16th to endDay
9%6%22%31%28%
315
July1st to 15thDay
5%1420%37%29%
305
16th to endDay
8%316%36%33%
326
August1st to 15thDay
11%15%21%33%27%
313
16th to endDay
13%15%21%32%25%
332
September1st to 15thDay
11%48%24%30%20%
315
16th to endDay
12%110%31%29%14%
275
October1st to 15thDay
9%318%32%29%6%
255
16th to endDay
15%321%28%21%9%
143
November1st to 15thDay
25%235%24%10%2
90
16th to endDay
12%11%35%27%11%2
90
December1st to 15thDay
22%18%34%20%22
90
16th to endDay
29%15%22%26%5%1
96
January1st to 15thNight
20%11%34%24%9%
720
16th to endNight
20%11%33%28%5%
768
February1st to 15thNight
18%10%33%30%6%
704
16th to endNight
19%12%33%28%4
631
March1st to 15thNight
17%11%33%26%9%
720
16th to endNight
15%9%27%29%17%
670
April1st to 15thNight
10%7%33%28%19%
539
16th to endNight
10%6%26%35%17%1
540
May1st to 15thNight
10%422%35%22%5%
540
16th to endNight
6%112%38%35%5%
563
June1st to 15thNight
7%7%32%41%9%
540
16th to endNight
5%15%23%48%14%
540
July1st to 15thNight
6%1327%43%17%
510
16th to endNight
6%1421%46%19%
564
August1st to 15thNight
7%1120%52%15%
539
16th to endNight
10%1425%41%16%
573
September1st to 15thNight
14%28%23%38%13%
600
16th to endNight
10%110%34%37%5%
681
October1st to 15thNight
12%218%33%30%3
660
16th to endNight
13%6%19%30%26%3
704
November1st to 15thNight
12%425%32%21%4
700
16th to endNight
13%9%28%33%12%1
720
December1st to 15thNight
17%9%27%32%11%
720
16th to endNight
23%10%26%30%7%
768
Page generated at 2017-09-22 06:35:38. Version ac04

Copyright 2017 A. Danko


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