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Cherry Springs State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cherry Springs State Park clear sky chart from 2005-11-05 to 2021-07-27.

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
28%
19863
14%
62276
8%
19825
36%
19825
16%
44132

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
12%
958
10%
3306
3%
956
22%
956
8%
2530
January16th to endNight
13%
1024
10%
3328
4%
1024
22%
1024
8%
2590
February1st to 15thNight
9%
944
10%
3067
2%
941
19%
941
7%
2414
February16th to endNight
13%
843
13%
2632
4%
843
24%
843
10%
1960
March1st to 15thNight
16%
960
16%
2664
6%
960
27%
960
12%
2012
March16th to endNight
19%
1024
18%
2797
7%
1024
29%
1024
17%
2002
April1st to 15thNight
19%
958
13%
2396
3%
958
25%
958
15%
1828
April16th to endNight
26%
883
16%
2309
5%
883
31%
883
22%
1591
May1st to 15thNight
31%
636
15%
2076
8%
636
38%
636
16%
1467
May16th to endNight
42%
502
14%
2009
14%
502
47%
502
16%
1294
June1st to 15thNight
42%
480
16%
1920
15%
480
53%
480
20%
1171
June16th to endNight
47%
480
15%
1920
18%
480
54%
480
22%
1146
July1st to 15thNight
53%
460
16%
1840
20%
460
58%
460
25%
1072
July16th to endNight
58%
634
17%
2028
16%
604
61%
604
28%
1232
August1st to 15thNight
57%
665
16%
1985
12%
662
60%
662
29%
1254
August16th to endNight
57%
871
20%
2305
11%
871
60%
871
32%
1478
September1st to 15thNight
45%
900
20%
2250
11%
900
49%
900
28%
1533
September16th to endNight
48%
897
23%
2485
17%
897
52%
897
30%
1588
October1st to 15thNight
35%
900
15%
2700
11%
900
43%
900
22%
1815
October16th to endNight
21%
960
15%
2880
6%
960
31%
960
15%
2102
November1st to 15thNight
27%
940
17%
3075
10%
940
36%
940
18%
2060
November16th to endNight
20%
960
12%
3360
7%
960
29%
960
11%
2494
December1st to 15thNight
15%
960
8%
3360
4%
960
21%
960
7%
2662
December16th to endNight
14%
1024
9%
3584
4%
1024
22%
1024
7%
2837

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
17%10%47%6%35%45%6%29%
63356
Night
15%10%47%6%35%45%6%31%
62455
Cloud CoverDay
17%9%47%6%35%45%6%30%
63366
Night
16%9%46%6%3445%6%32%
62459
TransparencyDay
53%5%10%18%10%1
63054
Night
51%6%12%19%10%1
62276
SeeingDay
26%16%26%17%9%3
10432
Night
23%16%27%22%9%1
19866

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
14%15%8%11%8%3444420%
1949
16th to endDay
12%16%8%13%9%45%34417%
2304
February1st to 15thDay
16%16%7%11%8%36%33417%
2115
16th to endDay
16%12%5%12%7%34335%25%
2005
March1st to 15thDay
15%12%5%9%6%34345%28%
2601
16th to endDay
17%11%5%7%6%2345%6%29%
2834
April1st to 15thDay
18%13%5%6%6%2345%5%28%
2872
16th to endDay
20%9%35%5%3444434%
2928
May1st to 15thDay
22%9%36%5%35%445%28%
3195
16th to endDay
18%6%35%6%35%45%7%32%
3514
June1st to 15thDay
16%7%36%6%45%5%5%7%32%
3360
16th to endDay
16%6%245%35%5%5%9%33%
3360
July1st to 15thDay
12%6%36%6%45%5%6%8%34%
3360
16th to endDay
13%6%26%6%36%6%5%8%33%
3345
August1st to 15thDay
14%6%37%6%46%5%6%8%31%
2877
16th to endDay
14%5%26%5%36%6%7%8%33%
2936
September1st to 15thDay
21%7%36%434445%34%
2700
16th to endDay
17%426%434446%41%
2464
October1st to 15thDay
20%7%36%4245%46%32%
2250
16th to endDay
23%11%36%6%34445%26%
2400
November1st to 15thDay
15%11%47%5%34447%32%
2099
16th to endDay
20%15%5%8%6%34445%23%
1920
December1st to 15thDay
18%16%7%13%6%35%34416%
1920
16th to endDay
19%16%7%10%7%35%45%414%
2048
January1st to 15thNight
16%13%5%10%8%36%5%46%19%
3306
16th to endNight
13%14%7%11%8%46%445%19%
3328
February1st to 15thNight
15%15%7%10%8%36%445%20%
3065
16th to endNight
15%11%5%10%8%35%446%23%
2632
March1st to 15thNight
15%11%5%8%6%45%446%28%
2652
16th to endNight
15%9%47%5%25%446%33%
2797
April1st to 15thNight
19%10%47%6%33446%28%
2396
16th to endNight
16%10%25%424346%37%
2309
May1st to 15thNight
19%8%37%5%35%445%33%
2076
16th to endNight
14%6%35%6%3445%7%37%
2007
June1st to 15thNight
14%5%245%3346%8%38%
1920
16th to endNight
12%5%25%435%5%5%8%41%
1920
July1st to 15thNight
9%5%25%43445%7%45%
1920
16th to endNight
10%5%245%3445%9%44%
2132
August1st to 15thNight
10%425%5%35%5%5%7%43%
1996
16th to endNight
11%5%2442446%8%44%
2305
September1st to 15thNight
16%6%25%5%23446%42%
2250
16th to endNight
15%5%25%433446%45%
2485
October1st to 15thNight
20%6%25%433346%38%
2700
16th to endNight
22%11%36%5%2335%6%29%
2880
November1st to 15thNight
15%9%35%6%35%446%35%
3075
16th to endNight
17%13%5%8%6%3445%6%23%
3360
December1st to 15thNight
18%15%6%9%6%36%5%5%5%17%
3360
16th to endNight
18%12%6%10%8%35%45%6%16%
3584

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
14%15%7%11%8%3435%5%21%
1949
16th to endDay
12%16%8%12%8%45%34418%
2304
February1st to 15thDay
17%16%6%10%9%35%34418%
2115
16th to endDay
16%12%412%7%24336%26%
2005
March1st to 15thDay
15%11%6%7%6%33445%29%
2612
16th to endDay
18%11%46%5%33446%30%
2833
April1st to 15thDay
18%13%5%6%434445%29%
2872
16th to endDay
20%9%36%5%34445%34%
2928
May1st to 15thDay
22%9%36%5%34446%28%
3195
16th to endDay
18%7%35%5%35%5%5%7%33%
3514
June1st to 15thDay
16%6%26%6%35%45%7%33%
3360
16th to endDay
15%5%25%6%35%5%5%9%34%
3360
July1st to 15thDay
12%6%36%6%45%5%6%8%35%
3360
16th to endDay
13%5%36%6%46%6%6%7%33%
3345
August1st to 15thDay
13%5%26%7%46%5%5%8%31%
2877
16th to endDay
13%6%25%6%45%6%6%8%33%
2936
September1st to 15thDay
20%7%25%434446%34%
2700
16th to endDay
17%425%5%34346%42%
2464
October1st to 15thDay
20%7%26%5%2345%7%33%
2250
16th to endDay
22%12%36%5%34445%28%
2400
November1st to 15thDay
15%12%36%6%35%445%34%
2099
16th to endDay
20%14%5%7%6%34345%24%
1920
December1st to 15thDay
18%16%6%11%6%35%345%18%
1920
16th to endDay
20%16%6%10%6%35%45%6%15%
2048
January1st to 15thNight
16%12%5%9%7%35%6%5%6%20%
3306
16th to endNight
13%12%6%10%8%45%5%5%5%21%
3328
February1st to 15thNight
15%14%6%9%7%45%445%21%
3058
16th to endNight
15%10%410%7%35%446%25%
2632
March1st to 15thNight
16%10%48%6%35%446%29%
2664
16th to endNight
15%9%46%5%34446%35%
2797
April1st to 15thNight
19%10%46%6%34445%29%
2396
16th to endNight
16%10%25%424346%38%
2309
May1st to 15thNight
20%7%35%6%34445%33%
2075
16th to endNight
14%7%25%5%35%45%7%37%
2007
June1st to 15thNight
14%5%25%425%5%5%8%40%
1920
16th to endNight
11%5%25%5%25%45%8%42%
1920
July1st to 15thNight
9%6%244245%5%9%45%
1920
16th to endNight
10%4245%245%5%9%44%
2132
August1st to 15thNight
9%6%245%35%5%5%8%43%
1996
16th to endNight
11%424444449%44%
2305
September1st to 15thNight
16%5%25%423446%42%
2250
16th to endNight
15%5%24423446%46%
2485
October1st to 15thNight
20%6%25%424346%39%
2700
16th to endNight
22%10%26%5%23446%30%
2880
November1st to 15thNight
15%9%35%5%3445%6%37%
3075
16th to endNight
17%12%47%6%35%446%25%
3360
December1st to 15thNight
18%13%6%8%5%35%5%5%6%19%
3360
16th to endNight
19%12%5%9%7%345%5%7%18%
3584

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
64%49%13%6%1
1950
16th to endDay
67%410%11%5%
2304
February1st to 15thDay
68%48%11%5%
2117
16th to endDay
60%37%18%7%1
2005
March1st to 15thDay
56%410%18%8%1
2612
16th to endDay
54%48%18%11%3
2834
April1st to 15thDay
56%5%9%17%10%1
2872
16th to endDay
51%5%7%18%15%2
2928
May1st to 15thDay
55%5%9%17%9%1
3195
16th to endDay
48%8%13%17%10%1
3518
June1st to 15thDay
48%7%11%19%11%
3360
16th to endDay
45%7%13%22%10%
3360
July1st to 15thDay
44%7%11%22%13%1
3211
16th to endDay
45%8%13%21%11%
3187
August1st to 15thDay
48%7%12%20%10%
2864
16th to endDay
45%7%12%20%12%1
2936
September1st to 15thDay
49%5%11%19%13%1
2700
16th to endDay
42%49%23%18%1
2464
October1st to 15thDay
50%5%10%19%13%1
2250
16th to endDay
57%411%18%7%1
2400
November1st to 15thDay
50%5%11%18%10%3
2099
16th to endDay
60%410%17%6%
1920
December1st to 15thDay
68%411%10%4
1920
16th to endDay
68%5%11%11%2
2048
January1st to 15thNight
61%5%11%13%6%
3306
16th to endNight
61%6%11%13%6%
3328
February1st to 15thNight
63%5%10%14%5%
3067
16th to endNight
57%410%17%8%1
2632
March1st to 15thNight
55%6%8%21%7%1
2664
16th to endNight
50%5%10%18%13%2
2797
April1st to 15thNight
55%6%9%18%10%
2396
16th to endNight
46%410%21%14%2
2309
May1st to 15thNight
51%5%10%20%11%1
2076
16th to endNight
44%7%13%19%12%2
2009
June1st to 15thNight
40%7%14%25%11%
1920
16th to endNight
37%8%13%26%13%
1920
July1st to 15thNight
35%7%13%26%15%1
1840
16th to endNight
35%7%15%21%18%1
2028
August1st to 15thNight
36%7%14%28%11%
1985
16th to endNight
36%6%13%27%14%1
2305
September1st to 15thNight
41%5%13%23%14%1
2250
16th to endNight
38%412%26%16%1
2485
October1st to 15thNight
45%5%13%19%15%1
2700
16th to endNight
53%5%14%17%8%
2880
November1st to 15thNight
46%5%14%18%11%3
3075
16th to endNight
58%5%11%17%6%
3360
December1st to 15thNight
63%6%11%13%3
3360
16th to endNight
64%6%11%14%3
3584

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
32%25%28%7%5%1
195
16th to endDay
37%26%26%8%1
288
February1st to 15thDay
40%30%26%2
270
16th to endDay
38%24%28%7%
346
March1st to 15thDay
28%25%30%12%3
510
16th to endDay
30%22%25%14%42
544
April1st to 15thDay
31%21%26%14%41
510
16th to endDay
28%22%26%11%7%2
499
May1st to 15thDay
36%19%22%10%7%3
528
16th to endDay
23%13%28%19%10%4
587
June1st to 15thDay
19%16%27%23%10%1
555
16th to endDay
19%12%33%22%9%2
555
July1st to 15thDay
13%8%26%27%16%7%
545
16th to endDay
16%6%28%27%15%5%
564
August1st to 15thDay
16%6%25%27%15%8%
478
16th to endDay
16%6%27%24%14%11%
524
September1st to 15thDay
23%9%19%23%16%8%
495
16th to endDay
17%10%20%22%20%8%
494
October1st to 15thDay
25%13%23%22%11%3
495
16th to endDay
33%19%27%14%4
528
November1st to 15thDay
28%17%26%16%9%1
370
16th to endDay
34%25%26%12%1
180
December1st to 15thDay
37%27%23%8%21
180
16th to endDay
42%27%22%6%1
192
January1st to 15thNight
26%25%30%13%3
960
16th to endNight
25%27%30%15%1
1024
February1st to 15thNight
30%23%33%11%1
944
16th to endNight
28%27%28%13%1
843
March1st to 15thNight
28%24%28%15%2
960
16th to endNight
23%21%31%17%5%
1024
April1st to 15thNight
27%19%30%19%3
958
16th to endNight
24%14%30%22%6%
883
May1st to 15thNight
24%11%26%25%11%
636
16th to endNight
16%10%25%32%14%
503
June1st to 15thNight
17%8%24%36%12%
480
16th to endNight
11%429%40%13%
480
July1st to 15thNight
11%323%36%22%1
460
16th to endNight
12%218%42%21%2
634
August1st to 15thNight
12%318%38%25%2
665
16th to endNight
13%418%34%25%3
871
September1st to 15thNight
19%6%21%30%20%2
900
16th to endNight
17%7%20%24%23%6%
897
October1st to 15thNight
23%11%24%23%15%1
900
16th to endNight
28%16%29%20%4
960
November1st to 15thNight
20%16%32%22%7%
940
16th to endNight
28%18%28%18%41
960
December1st to 15thNight
30%21%28%15%4
960
16th to endNight
30%23%27%16%2
1024
Page generated at 2021-07-28 18:31:18. Version ac04

Copyright 2021 A. Danko


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