Deep Creek Lake State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Deep Creek Lake State Park clear sky chart from 2005-11-05 to 2017-09-17.

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
30%
15260
15%
46935
8%
15221
37%
15221
16%
33397

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
10%
716
11%
2327
3%
716
20%
716
5%
1860
January16th to endNight
7%
768
9%
2496
1%
768
17%
768
6%
1971
February1st to 15thNight
9%
704
10%
2287
3%
701
19%
701
8%
1708
February16th to endNight
9%
631
12%
1932
2%
631
20%
631
7%
1509
March1st to 15thNight
17%
720
14%
1980
6%
720
24%
720
12%
1510
March16th to endNight
18%
768
16%
2112
8%
768
26%
768
14%
1552
April1st to 15thNight
20%
718
13%
1835
4%
718
25%
718
17%
1362
April16th to endNight
32%
642
17%
1722
7%
642
37%
642
21%
1214
May1st to 15thNight
33%
540
14%
1620
7%
540
39%
540
17%
1175
May16th to endNight
46%
459
16%
1582
13%
459
51%
459
22%
1027
June1st to 15thNight
48%
360
16%
1440
16%
360
55%
360
20%
886
June16th to endNight
45%
360
16%
1440
13%
360
53%
360
21%
878
July1st to 15thNight
48%
439
11%
1459
10%
439
50%
439
21%
976
July16th to endNight
59%
564
15%
1595
12%
531
62%
531
30%
989
August1st to 15thNight
57%
539
18%
1609
13%
536
59%
536
28%
1024
August16th to endNight
63%
675
23%
1821
16%
675
65%
675
35%
1127
September1st to 15thNight
50%
720
23%
1823
12%
720
54%
720
30%
1210
September16th to endNight
49%
665
21%
1856
17%
665
52%
665
27%
1233
October1st to 15thNight
40%
660
21%
1980
15%
660
49%
660
22%
1311
October16th to endNight
25%
704
19%
2112
8%
704
39%
704
17%
1451
November1st to 15thNight
30%
700
21%
2182
13%
700
42%
700
20%
1443
November16th to endNight
20%
720
13%
2520
7%
720
30%
720
10%
1842
December1st to 15thNight
17%
720
8%
2520
5%
720
22%
720
7%
2003
December16th to endNight
10%
768
9%
2685
3%
768
19%
768
5%
2136

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%9%47%6%35%5%5%7%29%
47820
Night
12%7%47%7%35%5%5%7%33%
47127
Cloud CoverDay
13%9%48%6%45%5%5%7%29%
47830
Night
11%7%47%6%45%5%5%7%33%
47131
TransparencyDay
51%8%10%17%10%1
47530
Night
47%9%11%19%11%1
46935
SeeingDay
22%16%24%18%12%5%
5521
Night
22%18%24%22%11%1
15266

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
12%10%7%12%9%6%5%5%5%5%19%
1611
16th to endDay
11%13%7%11%9%345%5%7%20%
1728
February1st to 15thDay
11%12%5%10%10%345%6%7%21%
1575
16th to endDay
10%12%6%14%7%46%5%45%23%
1536
March1st to 15thDay
14%10%48%7%35%45%6%28%
1969
16th to endDay
16%11%48%6%3445%7%26%
2112
April1st to 15thDay
14%11%46%6%245%5%6%32%
2113
16th to endDay
17%8%47%5%33445%34%
2247
May1st to 15thDay
20%8%37%6%35%5%5%6%26%
2331
16th to endDay
16%7%36%6%36%5%5%8%31%
2530
June1st to 15thDay
12%6%35%6%36%6%6%8%33%
2520
16th to endDay
13%7%37%6%46%6%6%9%29%
2520
July1st to 15thDay
13%7%47%8%46%5%6%8%28%
2408
16th to endDay
10%6%37%7%47%6%7%9%29%
2465
August1st to 15thDay
10%7%37%7%5%6%6%8%8%26%
2340
16th to endDay
12%5%25%7%36%6%7%9%32%
2369
September1st to 15thDay
14%6%36%6%345%5%6%37%
2135
16th to endDay
15%9%37%5%25%346%35%
1810
October1st to 15thDay
16%10%35%42445%6%36%
1650
16th to endDay
15%12%47%6%24335%35%
1760
November1st to 15thDay
9%10%46%5%25%45%6%38%
1675
16th to endDay
15%12%5%8%6%45%35%5%26%
1440
December1st to 15thDay
15%13%6%11%8%36%34421%
1440
16th to endDay
15%12%7%11%8%45%45%419%
1536
January1st to 15thNight
11%8%6%11%11%5%7%5%45%21%
2327
16th to endNight
11%11%6%10%9%5%7%5%45%22%
2496
February1st to 15thNight
10%7%49%9%5%6%5%6%7%26%
2285
16th to endNight
8%9%6%11%10%47%7%5%6%23%
1932
March1st to 15thNight
14%8%48%6%45%5%5%8%28%
1968
16th to endNight
16%7%47%6%34446%33%
2112
April1st to 15thNight
12%9%5%8%6%3445%7%32%
1835
16th to endNight
12%8%47%5%34446%38%
1722
May1st to 15thNight
18%5%37%5%25%5%6%8%32%
1620
16th to endNight
11%6%25%5%2446%9%40%
1580
June1st to 15thNight
7%5%25%5%45%5%8%9%39%
1440
16th to endNight
9%5%25%5%25%6%6%10%39%
1440
July1st to 15thNight
9%5%35%6%35%5%6%9%38%
1548
16th to endNight
7%424435%6%7%9%43%
1703
August1st to 15thNight
6%5%246%5%46%6%9%41%
1620
16th to endNight
7%4244345%47%50%
1821
September1st to 15thNight
11%5%35%5%2345%6%45%
1823
16th to endNight
11%7%25%5%2445%7%42%
1856
October1st to 15thNight
14%6%34435%45%6%40%
1980
16th to endNight
14%8%36%5%3345%5%38%
2112
November1st to 15thNight
11%9%37%5%3445%5%40%
2182
16th to endNight
14%8%6%8%7%36%45%6%28%
2520
December1st to 15thNight
14%10%6%12%11%47%45%419%
2520
16th to endNight
12%10%6%11%8%46%5%5%5%21%
2685

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%10%6%12%8%6%5%5%5%6%19%
1611
16th to endDay
11%12%7%11%8%45%45%7%21%
1728
February1st to 15thDay
11%11%6%9%10%35%6%5%7%21%
1575
16th to endDay
10%11%6%13%7%46%5%45%23%
1536
March1st to 15thDay
14%10%5%8%6%45%45%6%28%
1980
16th to endDay
16%11%5%7%6%35%45%7%26%
2111
April1st to 15thDay
13%10%5%7%5%345%5%6%32%
2113
16th to endDay
17%7%5%7%5%34446%34%
2247
May1st to 15thDay
20%8%27%6%45%5%5%6%25%
2331
16th to endDay
16%6%36%6%35%5%5%8%31%
2530
June1st to 15thDay
12%6%35%6%36%7%7%8%32%
2520
16th to endDay
11%7%37%7%46%6%6%9%29%
2520
July1st to 15thDay
12%7%38%7%46%6%6%8%28%
2408
16th to endDay
9%6%47%7%47%7%7%9%28%
2465
August1st to 15thDay
10%6%48%7%5%7%7%7%8%26%
2340
16th to endDay
12%6%26%7%46%7%6%8%32%
2369
September1st to 15thDay
13%5%46%6%3445%6%37%
2135
16th to endDay
15%9%37%5%24446%35%
1810
October1st to 15thDay
15%11%25%5%34446%36%
1650
16th to endDay
15%11%37%6%3433435%
1760
November1st to 15thDay
9%9%46%5%25%5%46%38%
1675
16th to endDay
15%11%6%8%8%35%35%6%26%
1440
December1st to 15thDay
15%11%7%11%7%46%44422%
1440
16th to endDay
14%12%6%11%8%46%45%5%19%
1536
January1st to 15thNight
11%8%6%11%10%5%7%5%46%21%
2327
16th to endNight
11%10%5%10%8%5%7%6%5%5%23%
2496
February1st to 15thNight
10%7%48%9%5%7%6%6%7%26%
2278
16th to endNight
8%9%6%11%10%46%6%5%6%23%
1932
March1st to 15thNight
14%8%5%8%6%45%5%5%7%28%
1980
16th to endNight
15%8%47%6%25%446%33%
2112
April1st to 15thNight
12%8%5%8%5%45%447%32%
1835
16th to endNight
11%8%47%6%34346%38%
1722
May1st to 15thNight
17%5%36%5%35%46%8%31%
1619
16th to endNight
10%6%35%5%25%45%9%40%
1580
June1st to 15thNight
7%5%346%45%5%7%9%40%
1440
16th to endNight
8%5%25%5%35%5%7%11%38%
1440
July1st to 15thNight
9%6%25%6%35%6%6%8%38%
1548
16th to endNight
7%4246%25%6%7%9%42%
1703
August1st to 15thNight
6%5%25%6%5%5%46%9%41%
1620
16th to endNight
7%4245%335%5%7%50%
1821
September1st to 15thNight
10%5%26%4235%5%6%45%
1823
16th to endNight
11%7%36%43435%7%42%
1856
October1st to 15thNight
13%7%24435%5%47%40%
1980
16th to endNight
14%8%36%6%3345%6%37%
2112
November1st to 15thNight
11%8%35%6%35%445%40%
2182
16th to endNight
14%8%5%8%7%35%45%6%28%
2520
December1st to 15thNight
14%9%6%12%9%5%7%5%4420%
2520
16th to endNight
12%11%6%12%7%47%5%5%6%21%
2685

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
61%9%9%12%41
1612
16th to endDay
60%9%10%14%5%
1728
February1st to 15thDay
58%9%11%13%6%
1577
16th to endDay
59%9%9%13%7%
1536
March1st to 15thDay
53%8%10%17%8%1
1980
16th to endDay
55%7%9%17%9%
2112
April1st to 15thDay
49%8%9%16%13%1
2113
16th to endDay
50%6%8%18%14%2
2247
May1st to 15thDay
56%8%9%15%9%
2331
16th to endDay
49%10%11%18%8%1
2534
June1st to 15thDay
44%10%11%21%10%
2520
16th to endDay
48%10%11%19%8%1
2520
July1st to 15thDay
50%9%10%16%11%1
2268
16th to endDay
45%10%12%18%11%1
2310
August1st to 15thDay
50%9%12%17%9%
2327
16th to endDay
44%9%11%22%10%1
2369
September1st to 15thDay
45%6%9%18%17%1
2135
16th to endDay
48%5%9%21%14%
1810
October1st to 15thDay
47%6%9%21%12%1
1650
16th to endDay
50%5%9%21%12%
1760
November1st to 15thDay
42%8%9%17%15%6%
1675
16th to endDay
57%7%8%14%11%
1440
December1st to 15thDay
62%8%8%12%5%1
1440
16th to endDay
63%10%9%11%6%
1536
January1st to 15thNight
59%10%8%11%6%2
2327
16th to endNight
57%12%11%12%5%
2496
February1st to 15thNight
52%10%12%15%8%
2287
16th to endNight
56%11%9%15%6%
1932
March1st to 15thNight
51%10%9%19%6%1
1980
16th to endNight
49%9%9%20%10%1
2112
April1st to 15thNight
50%7%9%18%12%1
1835
16th to endNight
45%6%9%18%14%4
1722
May1st to 15thNight
48%9%11%18%10%1
1620
16th to endNight
40%8%14%22%12%1
1582
June1st to 15thNight
37%9%12%27%11%
1440
16th to endNight
37%9%15%23%12%1
1440
July1st to 15thNight
40%11%13%19%11%2
1459
16th to endNight
31%11%16%24%14%2
1595
August1st to 15thNight
35%9%15%23%14%
1609
16th to endNight
31%8%12%31%14%1
1821
September1st to 15thNight
36%8%12%21%18%2
1823
16th to endNight
40%6%9%23%19%
1856
October1st to 15thNight
41%7%9%23%15%1
1980
16th to endNight
43%9%9%24%12%1
2112
November1st to 15thNight
43%6%10%18%14%6%
2182
16th to endNight
53%8%8%15%11%1
2520
December1st to 15thNight
61%10%9%11%5%1
2520
16th to endNight
60%11%11%12%4
2685

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
33%34%18%6%5%1
90
16th to endDay
42%32%16%6%2
96
February1st to 15thDay
38%37%22%1
90
16th to endDay
31%29%31%6%
132
March1st to 15thDay
31%27%22%14%4
270
16th to endDay
27%24%27%14%5%1
288
April1st to 15thDay
23%23%24%18%8%
270
16th to endDay
25%15%25%17%10%4
270
May1st to 15thDay
35%17%19%14%9%4
288
16th to endDay
23%16%19%20%11%8%
331
June1st to 15thDay
14%16%25%25%14%4
315
16th to endDay
15%18%30%16%13%5%
315
July1st to 15thDay
16%11%33%21%10%6%
305
16th to endDay
7%7%25%28%18%11%
326
August1st to 15thDay
14%7%24%21%21%9%
313
16th to endDay
12%6%21%23%18%17%
332
September1st to 15thDay
17%8%21%20%19%11%
315
16th to endDay
21%11%18%15%23%9%
259
October1st to 15thDay
22%12%20%24%17%2
255
16th to endDay
27%22%25%16%7%
272
November1st to 15thDay
22%13%25%20%15%1
205
16th to endDay
33%30%16%10%6%3
60
December1st to 15thDay
48%21%15%10%5%
60
16th to endDay
40%21%31%6%
64
January1st to 15thNight
32%30%23%10%2
720
16th to endNight
31%32%24%10%
768
February1st to 15thNight
31%29%26%12%
704
16th to endNight
24%35%27%11%
631
March1st to 15thNight
29%23%26%16%3
720
16th to endNight
23%23%30%15%5%
768
April1st to 15thNight
21%24%31%17%4
718
16th to endNight
22%14%25%27%10%1
642
May1st to 15thNight
21%13%26%27%11%
540
16th to endNight
15%9%22%27%22%2
461
June1st to 15thNight
10%9%27%34%17%1
360
16th to endNight
11%7%30%34%16%
360
July1st to 15thNight
11%7%24%35%19%1
439
16th to endNight
8%6%19%31%29%4
564
August1st to 15thNight
10%320%37%25%2
539
16th to endNight
10%316%38%27%3
675
September1st to 15thNight
15%7%21%30%21%3
720
16th to endNight
16%10%18%26%23%4
665
October1st to 15thNight
20%12%23%24%16%2
660
16th to endNight
26%20%25%21%5%
704
November1st to 15thNight
20%18%25%22%10%1
700
16th to endNight
30%20%24%17%5%1
720
December1st to 15thNight
30%23%23%16%5%
720
16th to endNight
30%29%25%13%1
768
Page generated at 2017-09-18 08:38:23. Version ac04

Copyright 2017 A. Danko


Deep Creek Lake State Park Clear Sky Chart | Charts Home