Droop Mountain Battlefield State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Droop Mountain Battlefield State Park clear sky chart from 2005-11-05 to 2018-02-14.

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
40%
16354
16%
49076
11%
16316
46%
16316
21%
32760

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
19%
778
15%
2522
7%
776
29%
776
11%
1759
January16th to endNight
16%
832
14%
2704
5%
832
28%
832
13%
1843
February1st to 15thNight
19%
757
14%
2468
5%
757
30%
757
14%
1638
February16th to endNight
15%
631
14%
1894
5%
631
26%
631
13%
1347
March1st to 15thNight
25%
720
15%
1980
8%
720
32%
720
17%
1382
March16th to endNight
26%
768
14%
2112
8%
768
31%
768
17%
1530
April1st to 15thNight
30%
718
14%
1874
6%
718
36%
718
22%
1309
April16th to endNight
42%
620
18%
1700
9%
620
47%
620
24%
1126
May1st to 15thNight
39%
540
12%
1620
7%
540
44%
540
20%
1146
May16th to endNight
53%
561
13%
1684
10%
561
56%
561
24%
1128
June1st to 15thNight
62%
540
14%
1620
11%
540
65%
540
28%
1029
June16th to endNight
62%
540
16%
1620
11%
540
66%
540
30%
997
July1st to 15thNight
60%
510
10%
1530
9%
510
61%
510
24%
1031
July16th to endNight
73%
564
15%
1595
12%
531
75%
531
33%
969
August1st to 15thNight
66%
539
18%
1609
14%
536
66%
536
27%
1070
August16th to endNight
68%
659
20%
1805
16%
659
68%
659
33%
1150
September1st to 15thNight
61%
720
22%
1885
16%
720
63%
720
33%
1208
September16th to endNight
52%
717
21%
1980
17%
717
54%
717
27%
1318
October1st to 15thNight
50%
720
22%
2148
21%
720
55%
720
26%
1346
October16th to endNight
38%
768
24%
2304
16%
768
49%
768
24%
1441
November1st to 15thNight
42%
760
22%
2349
16%
760
51%
760
24%
1475
November16th to endNight
35%
780
20%
2607
14%
780
44%
780
19%
1641
December1st to 15thNight
24%
780
11%
2730
7%
780
29%
780
11%
1904
December16th to endNight
21%
832
15%
2736
7%
832
31%
832
12%
1973

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%6%36%6%35%5%5%7%33%
48975
Night
12%6%25%5%35%5%6%8%38%
49269
Cloud CoverDay
15%6%36%6%35%5%5%7%34%
48985
Night
13%5%25%5%35%5%6%7%39%
49273
TransparencyDay
47%7%12%18%11%1
48686
Night
42%7%15%20%12%2
49076
SeeingDay
20%12%21%21%15%8%
6018
Night
20%13%20%27%16%2
16361

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
13%7%48%8%45%6%46%28%
1746
16th to endDay
13%8%47%6%35%36%6%34%
1872
February1st to 15thDay
13%7%37%7%345%5%6%33%
1695
16th to endDay
13%8%49%5%35%5%46%32%
1575
March1st to 15thDay
14%6%37%5%2445%6%38%
1969
16th to endDay
16%9%46%5%34445%34%
2112
April1st to 15thDay
13%7%5%5%5%34447%40%
2074
16th to endDay
17%6%36%5%3445%7%35%
2270
May1st to 15thDay
20%7%36%7%36%45%7%28%
2331
16th to endDay
13%6%27%8%47%5%6%8%29%
2431
June1st to 15thDay
11%5%25%6%46%7%6%9%33%
2340
16th to endDay
10%5%37%7%47%5%7%7%32%
2340
July1st to 15thDay
14%6%36%7%46%7%6%8%27%
2340
16th to endDay
9%6%38%7%48%6%6%9%28%
2465
August1st to 15thDay
15%6%36%6%47%7%8%9%24%
2340
16th to endDay
10%5%38%7%5%7%6%7%8%29%
2384
September1st to 15thDay
14%6%26%5%345%5%7%36%
2072
16th to endDay
19%5%36%6%36%45%5%32%
1980
October1st to 15thDay
17%6%25%42335%6%40%
1812
16th to endDay
16%6%25%433345%44%
1920
November1st to 15thDay
12%6%25%43445%6%44%
1835
16th to endDay
13%6%36%6%345%45%40%
1679
December1st to 15thDay
16%9%35%5%36%45%6%32%
1560
16th to endDay
17%9%46%6%445%5%5%31%
1833
January1st to 15thNight
15%5%27%6%46%5%6%7%30%
2522
16th to endNight
13%7%36%6%35%5%5%8%33%
2704
February1st to 15thNight
11%6%36%6%346%6%8%35%
2466
16th to endNight
11%6%37%7%37%6%6%8%30%
1894
March1st to 15thNight
14%6%26%5%46%46%6%35%
1968
16th to endNight
14%7%26%6%35%5%6%7%34%
2112
April1st to 15thNight
12%5%35%6%35%45%9%37%
1874
16th to endNight
13%6%24435%5%5%9%40%
1700
May1st to 15thNight
18%7%35%5%345%47%36%
1620
16th to endNight
12%5%25%5%25%47%10%39%
1682
June1st to 15thNight
8%4235%25%5%7%11%44%
1620
16th to endNight
7%415%4245%7%9%46%
1620
July1st to 15thNight
10%5%25%5%35%6%6%8%40%
1620
16th to endNight
5%3145%35%5%7%12%44%
1703
August1st to 15thNight
13%3146%46%47%9%39%
1620
16th to endNight
9%6%2443446%7%45%
1805
September1st to 15thNight
12%41442446%6%47%
1885
16th to endNight
16%6%145%335%47%41%
1980
October1st to 15thNight
14%5%25%443446%44%
2148
16th to endNight
12%4245%346%46%43%
2304
November1st to 15thNight
11%6%35%42445%7%43%
2349
16th to endNight
14%5%35%5%35%5%46%40%
2607
December1st to 15thNight
14%7%37%7%46%5%5%6%30%
2730
16th to endNight
15%8%35%7%45%6%6%7%30%
2736

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%7%5%8%8%45%5%5%6%29%
1746
16th to endDay
14%8%48%5%3445%5%35%
1872
February1st to 15thDay
13%8%47%6%35%45%6%34%
1695
16th to endDay
14%9%49%6%25%446%32%
1575
March1st to 15thDay
15%6%37%425%35%6%39%
1980
16th to endDay
17%9%35%5%34445%35%
2111
April1st to 15thDay
13%7%45%42445%6%41%
2074
16th to endDay
18%5%25%5%345%5%7%36%
2270
May1st to 15thDay
20%6%36%6%35%5%5%6%29%
2331
16th to endDay
13%6%27%6%5%6%5%5%8%31%
2431
June1st to 15thDay
13%425%6%46%6%6%9%34%
2340
16th to endDay
11%5%36%7%47%6%7%7%32%
2340
July1st to 15thDay
15%6%36%7%35%7%5%9%28%
2340
16th to endDay
9%6%46%7%47%7%7%9%29%
2465
August1st to 15thDay
16%6%26%6%47%7%7%9%25%
2340
16th to endDay
11%5%27%7%47%6%7%8%30%
2384
September1st to 15thDay
15%5%25%5%35%6%5%8%37%
2072
16th to endDay
20%5%36%5%35%45%5%33%
1980
October1st to 15thDay
18%5%245%23346%41%
1812
16th to endDay
16%7%24423335%45%
1920
November1st to 15thDay
12%6%2443435%6%45%
1835
16th to endDay
14%6%35%5%3445%5%40%
1679
December1st to 15thDay
16%9%35%5%35%45%6%33%
1560
16th to endDay
18%8%36%5%4445%5%31%
1833
January1st to 15thNight
15%5%37%6%46%5%6%7%31%
2522
16th to endNight
13%7%47%6%35%45%7%34%
2704
February1st to 15thNight
12%6%27%6%345%5%8%36%
2459
16th to endNight
11%6%37%8%36%6%6%7%31%
1894
March1st to 15thNight
14%5%36%5%36%6%5%6%36%
1980
16th to endNight
14%6%36%6%245%5%7%35%
2112
April1st to 15thNight
12%6%35%6%35%45%8%38%
1874
16th to endNight
13%6%24435%46%8%40%
1700
May1st to 15thNight
17%7%25%42445%7%36%
1619
16th to endNight
12%5%25%5%2446%9%40%
1682
June1st to 15thNight
8%324435%5%7%10%45%
1620
16th to endNight
8%415%4245%7%10%46%
1620
July1st to 15thNight
10%5%15%5%35%6%6%8%40%
1620
16th to endNight
5%324435%5%7%11%46%
1703
August1st to 15thNight
12%4135%36%5%6%8%40%
1620
16th to endNight
10%5%25%5%3346%8%45%
1805
September1st to 15thNight
13%41442445%7%48%
1885
16th to endNight
16%6%24434447%42%
1980
October1st to 15thNight
14%5%14433446%46%
2148
16th to endNight
12%5%245%25%45%6%43%
2304
November1st to 15thNight
12%6%3442445%7%44%
2349
16th to endNight
15%434435%5%5%6%41%
2607
December1st to 15thNight
16%6%36%8%46%5%5%6%30%
2730
16th to endNight
16%7%36%7%345%6%7%30%
2736

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
54%6%12%15%9%1
1747
16th to endDay
49%414%18%11%1
1872
February1st to 15thDay
50%5%12%19%10%1
1697
16th to endDay
52%6%11%18%9%
1575
March1st to 15thDay
45%5%13%22%10%2
1980
16th to endDay
51%5%11%19%10%1
2112
April1st to 15thDay
43%6%11%21%13%3
2074
16th to endDay
47%6%11%17%14%3
2270
May1st to 15thDay
53%8%11%16%8%1
2331
16th to endDay
49%9%13%17%7%1
2435
June1st to 15thDay
44%10%14%19%11%
2340
16th to endDay
46%9%14%15%12%1
2340
July1st to 15thDay
50%10%11%13%11%2
2201
16th to endDay
46%11%12%16%11%
2310
August1st to 15thDay
50%9%15%15%8%
2327
16th to endDay
48%10%13%18%7%1
2384
September1st to 15thDay
43%7%11%19%16%2
2072
16th to endDay
50%6%8%17%15%1
1980
October1st to 15thDay
43%5%12%20%14%3
1812
16th to endDay
41%311%26%14%2
1920
November1st to 15thDay
39%5%12%19%18%5%
1835
16th to endDay
44%312%21%16%1
1679
December1st to 15thDay
49%6%13%16%11%2
1560
16th to endDay
53%5%13%19%7%1
1833
January1st to 15thNight
49%6%14%16%10%2
2522
16th to endNight
48%5%16%18%10%1
2704
February1st to 15thNight
44%6%16%20%10%1
2468
16th to endNight
48%7%15%18%8%
1894
March1st to 15thNight
46%6%14%21%9%1
1980
16th to endNight
46%9%13%18%10%1
2112
April1st to 15thNight
44%6%13%19%12%2
1874
16th to endNight
40%6%15%18%14%4
1700
May1st to 15thNight
47%8%16%15%11%
1620
16th to endNight
39%10%19%22%6%1
1684
June1st to 15thNight
32%12%18%23%12%
1620
16th to endNight
31%11%19%25%11%
1620
July1st to 15thNight
39%11%15%18%11%3
1530
16th to endNight
27%12%20%25%12%1
1595
August1st to 15thNight
38%9%16%21%12%
1609
16th to endNight
35%7%16%26%11%1
1805
September1st to 15thNight
34%8%15%19%20%2
1885
16th to endNight
40%7%11%24%16%
1980
October1st to 15thNight
39%412%24%15%3
2148
16th to endNight
39%412%25%16%2
2304
November1st to 15thNight
39%5%12%18%18%6%
2349
16th to endNight
42%413%20%16%2
2607
December1st to 15thNight
52%5%15%15%9%1
2730
16th to endNight
51%7%13%18%8%
2736

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
31%26%23%11%5%1
135
16th to endDay
39%22%25%10%2
144
February1st to 15thDay
35%34%23%6%
130
16th to endDay
27%26%27%16%2
111
March1st to 15thDay
29%18%24%20%7%
270
16th to endDay
23%21%25%20%7%1
288
April1st to 15thDay
18%22%21%23%12%1
270
16th to endDay
21%11%25%17%17%6%
270
May1st to 15thDay
26%16%23%13%13%5%
288
16th to endDay
19%10%19%21%18%11%
331
June1st to 15thDay
14%9%19%25%18%12%
315
16th to endDay
12%11%28%22%15%9%
315
July1st to 15thDay
18%5%29%21%14%11%
305
16th to endDay
10%216%31%20%18%
326
August1st to 15thDay
20%314%23%20%16%
313
16th to endDay
9%214%24%25%23%
332
September1st to 15thDay
15%6%14%22%25%15%
315
16th to endDay
19%7%14%23%23%11%
314
October1st to 15thDay
19%8%17%26%23%5%
315
16th to endDay
22%13%24%21%16%2
336
November1st to 15thDay
24%11%20%26%16%1
253
16th to endDay
26%22%24%19%5%
117
December1st to 15thDay
33%28%14%13%6%3
90
16th to endDay
39%28%21%10%
135
January1st to 15thNight
29%23%24%17%5%
780
16th to endNight
27%22%29%18%1
832
February1st to 15thNight
28%21%28%20%1
760
16th to endNight
22%27%31%17%1
631
March1st to 15thNight
24%19%27%24%4
720
16th to endNight
21%19%26%23%8%
768
April1st to 15thNight
18%20%26%26%7%
718
16th to endNight
20%10%21%30%15%1
620
May1st to 15thNight
23%8%22%31%12%1
540
16th to endNight
15%5%16%29%29%3
563
June1st to 15thNight
8%415%34%32%3
540
16th to endNight
9%316%39%28%2
540
July1st to 15thNight
13%212%37%31%2
510
16th to endNight
5%38%32%40%8%
564
August1st to 15thNight
15%9%38%32%3
539
16th to endNight
12%17%32%38%6%
659
September1st to 15thNight
15%412%30%31%5%
720
16th to endNight
19%414%27%28%4
717
October1st to 15thNight
17%10%15%30%23%3
720
16th to endNight
19%16%22%24%16%1
768
November1st to 15thNight
17%13%20%30%15%1
760
16th to endNight
24%16%20%28%9%1
780
December1st to 15thNight
25%21%23%22%6%
780
16th to endNight
28%17%27%22%3
832
Page generated at 2018-02-15 10:58:50. Version ac04

Copyright 2018 A. Danko


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