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Staunton River State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Staunton River State Park clear sky chart from 2005-11-05 to 2017-09-10.

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
43%
15671
22%
46966
13%
15634
52%
15634
27%
29563

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
26%
717
23%
2327
10%
716
43%
716
20%
1433
January16th to endNight
23%
768
24%
2496
12%
768
39%
768
23%
1521
February1st to 15thNight
23%
701
22%
2287
8%
701
42%
701
23%
1353
February16th to endNight
21%
631
28%
1874
10%
631
41%
631
26%
1131
March1st to 15thNight
29%
720
25%
1980
12%
720
41%
720
27%
1255
March16th to endNight
29%
768
21%
2112
10%
768
38%
768
25%
1406
April1st to 15thNight
32%
718
22%
1829
7%
718
42%
718
31%
1174
April16th to endNight
40%
720
21%
1800
8%
720
45%
720
32%
1192
May1st to 15thNight
38%
556
17%
1636
8%
556
44%
556
23%
1097
May16th to endNight
59%
561
17%
1683
13%
561
63%
561
30%
1069
June1st to 15thNight
65%
387
18%
1467
20%
387
68%
387
27%
859
June16th to endNight
68%
447
17%
1527
17%
447
70%
447
29%
942
July1st to 15thNight
65%
510
13%
1530
12%
510
67%
510
28%
994
July16th to endNight
69%
564
16%
1595
13%
531
72%
531
30%
1006
August1st to 15thNight
66%
539
18%
1609
14%
536
67%
536
25%
1081
August16th to endNight
64%
735
17%
1881
12%
735
65%
735
28%
1319
September1st to 15thNight
63%
700
25%
1752
18%
700
65%
700
33%
1171
September16th to endNight
48%
657
16%
1846
13%
657
52%
657
22%
1315
October1st to 15thNight
49%
660
27%
1980
24%
660
56%
660
29%
1235
October16th to endNight
45%
704
33%
2112
21%
704
62%
704
35%
1186
November1st to 15thNight
45%
700
27%
2101
18%
700
57%
700
33%
1226
November16th to endNight
41%
720
24%
2436
17%
720
52%
720
27%
1401
December1st to 15thNight
32%
720
21%
2520
12%
720
45%
720
21%
1553
December16th to endNight
27%
768
23%
2586
12%
768
42%
768
19%
1644

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
13%5%244245%5%7%43%
47630
Night
13%5%2442445%7%45%
47160
Cloud CoverDay
13%424435%45%7%43%
47640
Night
13%5%2442445%7%45%
47164
TransparencyDay
38%6%12%21%16%3
47341
Night
38%6%10%21%19%4
46967
SeeingDay
16%8%23%24%19%7%
5673
Night
16%8%25%30%17%1
15679

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
17%6%24424346%44%
1611
16th to endDay
17%6%23413346%47%
1728
February1st to 15thDay
14%6%244335%36%45%
1575
16th to endDay
15%4244245%47%44%
1595
March1st to 15thDay
14%5%33333446%47%
1969
16th to endDay
18%6%24434445%42%
2112
April1st to 15thDay
10%42331345%7%52%
2119
16th to endDay
14%425%5%245%46%43%
2160
May1st to 15thDay
17%5%25%5%3445%8%36%
2325
16th to endDay
12%3145%35%5%7%9%40%
2431
June1st to 15thDay
8%323436%6%7%10%43%
2487
16th to endDay
7%425%5%35%7%7%9%42%
2427
July1st to 15thDay
8%426%6%47%6%8%11%34%
2340
16th to endDay
6%5%16%6%47%8%8%11%33%
2465
August1st to 15thDay
10%6%36%6%36%6%6%10%33%
2340
16th to endDay
11%5%25%6%46%6%6%9%35%
2309
September1st to 15thDay
9%324435%5%6%8%44%
2095
16th to endDay
22%6%25%5%24445%35%
1782
October1st to 15thDay
18%423312225%52%
1650
16th to endDay
12%414413235%55%
1760
November1st to 15thDay
14%423324235%52%
1757
16th to endDay
14%42342345%5%49%
1518
December1st to 15thDay
15%42332445%5%47%
1440
16th to endDay
21%6%24314337%41%
1635
January1st to 15thNight
15%5%24424436%45%
2327
16th to endNight
16%5%24324245%47%
2496
February1st to 15thNight
16%5%2332335%5%48%
2285
16th to endNight
11%7%24324346%49%
1874
March1st to 15thNight
14%5%2442345%6%47%
1968
16th to endNight
17%5%25%423445%43%
2112
April1st to 15thNight
13%42431445%6%48%
1829
16th to endNight
13%5%1442445%6%45%
1800
May1st to 15thNight
15%5%25%4245%5%7%38%
1636
16th to endNight
11%415%4245%6%9%44%
1682
June1st to 15thNight
9%314435%5%5%11%45%
1467
16th to endNight
6%3246%36%6%7%10%43%
1527
July1st to 15thNight
8%325%6%35%7%7%10%39%
1620
16th to endNight
5%4245%47%6%7%12%38%
1703
August1st to 15thNight
9%435%6%46%47%9%38%
1620
16th to endNight
8%425%7%45%6%7%11%35%
1881
September1st to 15thNight
10%5%3442445%7%46%
1752
16th to endNight
20%7%25%42445%437%
1846
October1st to 15thNight
17%5%24323336%48%
1980
16th to endNight
12%313323345%56%
2112
November1st to 15thNight
12%5%24312345%53%
2101
16th to endNight
15%414323446%50%
2436
December1st to 15thNight
15%6%25%5%24345%44%
2520
16th to endNight
20%6%34423346%40%
2586

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
17%6%24414346%44%
1611
16th to endDay
17%6%23323346%47%
1728
February1st to 15thDay
14%6%145%235%37%45%
1575
16th to endDay
15%425%43345%7%44%
1595
March1st to 15thDay
14%5%23333446%47%
1980
16th to endDay
17%6%24434345%43%
2111
April1st to 15thDay
10%42331345%8%52%
2119
16th to endDay
14%425%425%5%46%44%
2160
May1st to 15thDay
17%426%5%25%45%8%36%
2325
16th to endDay
11%3245%35%5%7%9%40%
2431
June1st to 15thDay
8%324436%6%6%10%44%
2487
16th to endDay
6%425%5%35%6%7%9%42%
2427
July1st to 15thDay
8%426%6%47%6%7%11%34%
2340
16th to endDay
6%425%7%47%7%9%10%34%
2465
August1st to 15thDay
10%5%36%6%5%6%6%6%10%33%
2340
16th to endDay
10%5%25%6%36%6%6%9%34%
2309
September1st to 15thDay
9%424436%5%5%8%44%
2095
16th to endDay
21%6%35%424445%35%
1782
October1st to 15thDay
18%423312235%52%
1650
16th to endDay
12%414323235%55%
1760
November1st to 15thDay
14%423323335%51%
1757
16th to endDay
14%32332445%5%49%
1518
December1st to 15thDay
15%423324446%46%
1440
16th to endDay
21%6%23414346%41%
1635
January1st to 15thNight
15%5%24424336%45%
2327
16th to endNight
16%5%24423345%47%
2496
February1st to 15thNight
15%5%23323445%48%
2278
16th to endNight
12%6%24423445%49%
1874
March1st to 15thNight
14%5%23333446%47%
1980
16th to endNight
17%5%25%5%23446%43%
2112
April1st to 15thNight
12%5%2341445%6%48%
1829
16th to endNight
14%4244245%5%6%45%
1800
May1st to 15thNight
15%5%25%4245%5%7%39%
1635
16th to endNight
11%4244245%6%9%44%
1682
June1st to 15thNight
9%3144445%5%10%45%
1467
16th to endNight
6%3246%36%6%7%10%43%
1527
July1st to 15thNight
8%325%6%35%7%7%10%39%
1620
16th to endNight
5%4345%36%6%7%11%38%
1703
August1st to 15thNight
9%436%6%46%5%7%8%37%
1620
16th to endNight
8%5%25%7%447%8%11%34%
1881
September1st to 15thNight
11%5%344245%6%6%46%
1752
16th to endNight
19%7%25%43444437%
1846
October1st to 15thNight
16%5%14422336%48%
1980
16th to endNight
12%313323345%56%
2112
November1st to 15thNight
12%5%24322345%53%
2101
16th to endNight
15%423323436%50%
2436
December1st to 15thNight
15%6%25%5%24345%44%
2520
16th to endNight
20%6%35%42335%6%40%
2586

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
41%49%20%19%3
1612
16th to endDay
38%39%25%17%5%
1728
February1st to 15thDay
39%48%22%20%4
1577
16th to endDay
38%5%12%22%18%3
1595
March1st to 15thDay
37%5%9%22%19%5%
1980
16th to endDay
43%5%9%21%15%4
2112
April1st to 15thDay
30%411%27%18%7%
2119
16th to endDay
40%5%11%18%18%6%
2160
May1st to 15thDay
45%5%13%20%12%2
2325
16th to endDay
37%7%16%25%10%1
2435
June1st to 15thDay
33%8%17%24%14%1
2487
16th to endDay
34%10%16%19%16%2
2427
July1st to 15thDay
39%10%15%17%13%3
2201
16th to endDay
38%10%17%20%11%
2310
August1st to 15thDay
43%10%12%21%10%1
2327
16th to endDay
42%8%14%20%11%1
2309
September1st to 15thDay
36%8%13%16%22%3
2095
16th to endDay
48%6%8%16%18%2
1782
October1st to 15thDay
36%48%25%20%4
1650
16th to endDay
33%45%27%22%6%
1760
November1st to 15thDay
35%38%20%25%7%
1757
16th to endDay
35%5%9%22%23%4
1518
December1st to 15thDay
37%5%9%24%18%4
1440
16th to endDay
44%410%20%17%3
1635
January1st to 15thNight
40%48%17%22%6%
2327
16th to endNight
39%38%23%20%4
2496
February1st to 15thNight
37%36%23%22%5%
2287
16th to endNight
36%38%24%21%4
1874
March1st to 15thNight
37%5%9%23%20%4
1980
16th to endNight
42%48%21%19%3
2112
April1st to 15thNight
35%5%9%21%21%6%
1829
16th to endNight
38%410%19%17%8%
1800
May1st to 15thNight
41%8%11%20%14%2
1636
16th to endNight
35%8%15%25%13%2
1684
June1st to 15thNight
33%8%15%24%15%2
1467
16th to endNight
34%9%14%20%17%3
1527
July1st to 15thNight
34%11%15%20%13%4
1530
16th to endNight
33%10%18%23%12%1
1595
August1st to 15thNight
40%10%15%16%16%1
1609
16th to endNight
39%11%16%19%10%2
1881
September1st to 15thNight
36%7%11%19%18%5%
1752
16th to endNight
48%6%8%12%20%2
1846
October1st to 15thNight
38%47%23%20%4
1980
16th to endNight
30%36%25%25%8%
2112
November1st to 15thNight
33%38%18%26%10%
2101
16th to endNight
34%48%20%23%8%
2436
December1st to 15thNight
41%49%20%19%4
2520
16th to endNight
45%310%20%16%4
2586

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
26%20%42%11%
90
16th to endDay
21%36%30%11%
96
February1st to 15thDay
17%34%42%41
90
16th to endDay
18%21%34%22%3
185
March1st to 15thDay
19%17%34%19%8%
270
16th to endDay
18%12%37%21%8%1
288
April1st to 15thDay
14%15%31%24%11%2
270
16th to endDay
19%6%28%27%12%4
270
May1st to 15thDay
20%14%29%20%10%3
288
16th to endDay
18%319%25%25%7%
331
June1st to 15thDay
10%322%26%26%11%
315
16th to endDay
10%322%28%26%7%
315
July1st to 15thDay
11%18%34%28%6%
305
16th to endDay
5%112%29%35%15%
326
August1st to 15thDay
13%215%24%27%15%
313
16th to endDay
11%19%31%30%17%
332
September1st to 15thDay
12%412%26%24%18%
294
16th to endDay
34%115%16%20%10%
254
October1st to 15thDay
23%7%20%21%20%7%
255
16th to endDay
14%7%25%31%18%2
272
November1st to 15thDay
20%6%27%25%18%2
265
16th to endDay
13%14%18%34%14%3
108
December1st to 15thDay
20%16%36%15%6%5%
60
16th to endDay
37%17%25%16%3
81
January1st to 15thNight
18%18%32%25%5%
720
16th to endNight
19%14%37%25%2
768
February1st to 15thNight
21%15%36%25%1
704
16th to endNight
17%16%40%22%3
631
March1st to 15thNight
18%14%34%27%5%
720
16th to endNight
19%10%36%24%8%
768
April1st to 15thNight
15%15%35%25%8%
718
16th to endNight
16%6%32%30%13%
720
May1st to 15thNight
18%7%28%32%13%
556
16th to endNight
13%117%33%30%2
563
June1st to 15thNight
10%116%41%28%1
387
16th to endNight
7%114%44%29%2
447
July1st to 15thNight
7%13%38%35%4
510
16th to endNight
6%12%35%39%5%
564
August1st to 15thNight
11%10%38%34%4
539
16th to endNight
11%111%32%36%6%
735
September1st to 15thNight
14%112%33%33%4
700
16th to endNight
24%315%29%26%1
657
October1st to 15thNight
20%420%28%22%2
660
16th to endNight
14%8%28%28%17%2
704
November1st to 15thNight
15%8%26%31%16%1
700
16th to endNight
17%11%26%29%14%1
720
December1st to 15thNight
20%11%31%27%9%
720
16th to endNight
24%12%29%29%4
768
Page generated at 2017-09-11 19:35:26. Version ac04

Copyright 2017 A. Danko


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