Bluerock Campground
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bluerock Campground clear sky chart from 2005-11-05 to 2017-09-19.

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%
15151
13%
46821
6%
15118
38%
15118
19%
30791

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
15%
900
12%
2685
3%
895
23%
895
14%
1878
January16th to endNight
18%
783
17%
2703
7%
783
33%
783
15%
1741
February1st to 15thNight
26%
701
13%
2426
7%
697
36%
697
16%
1559
February16th to endNight
28%
632
15%
1953
8%
632
38%
632
18%
1323
March1st to 15thNight
19%
720
14%
2130
3%
720
32%
720
17%
1414
March16th to endNight
26%
768
11%
2070
2%
768
33%
768
16%
1511
April1st to 15thNight
30%
646
10%
1726
3%
646
34%
646
15%
1262
April16th to endNight
33%
540
10%
1620
7%
540
37%
540
16%
1152
May1st to 15thNight
41%
410
9%
1440
10%
410
43%
410
16%
960
May16th to endNight
41%
374
5%
1309
4%
374
43%
374
14%
959
June1st to 15thNight
37%
360
2%
1260
0%
360
37%
360
15%
889
June16th to endNight
44%
360
2%
1260
0%
360
44%
360
19%
812
July1st to 15thNight
50%
340
4%
1190
0%
340
52%
340
26%
704
July16th to endNight
57%
376
10%
1315
11%
354
62%
354
30%
714
August1st to 15thNight
60%
390
16%
1462
18%
388
65%
388
28%
817
August16th to endNight
54%
573
21%
1719
18%
573
57%
573
37%
929
September1st to 15thNight
51%
690
17%
1825
9%
690
54%
690
35%
1105
September16th to endNight
40%
671
18%
1856
9%
671
48%
671
28%
1147
October1st to 15thNight
32%
660
15%
1943
7%
660
41%
660
17%
1351
October16th to endNight
27%
704
19%
2288
7%
704
43%
704
19%
1457
November1st to 15thNight
14%
793
16%
2368
3%
793
27%
793
16%
1521
November16th to endNight
18%
900
13%
2693
3%
900
26%
900
16%
1802
December1st to 15thNight
21%
900
14%
2700
6%
900
28%
900
16%
1830
December16th to endNight
18%
960
15%
2880
3%
960
30%
960
15%
1954

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
8%9%47%6%35%5%6%8%31%
48031
Night
47%37%5%35%5%6%9%39%
46975
Cloud CoverDay
9%9%47%5%35%5%6%8%34%
48032
Night
5%7%36%5%35%5%6%8%41%
46978
TransparencyDay
46%10%16%18%7%1
47689
Night
38%10%18%21%9%1
46821
SeeingDay
17%19%30%20%8%2
5990
Night
10%19%32%23%10%2
15156

By Month

Percentage Cloud Cover NW (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
447%6%36%7%7%12%38%
1253
16th to endDay
5%5%8%6%46%5%6%12%35%
1530
February1st to 15thDay
15%5%8%8%47%7%8%10%33%
1437
16th to endDay
16%7%12%8%46%7%7%10%27%
1521
March1st to 15thDay
5%5%9%8%46%6%9%11%32%
1829
16th to endDay
314%5%12%9%47%6%7%8%19%
2152
April1st to 15thDay
6%17%7%9%5%46%6%7%9%20%
2221
16th to endDay
9%19%7%7%4345%6%8%24%
2340
May1st to 15thDay
8%15%47%6%45%5%6%7%28%
2510
16th to endDay
22%13%37%7%35%5%46%19%
2802
June1st to 15thDay
20%10%5%8%7%46%45%6%20%
2700
16th to endDay
14%9%47%7%5%6%5%5%7%26%
2700
July1st to 15thDay
10%6%26%6%47%6%7%8%32%
2700
16th to endDay
7%5%25%7%46%5%6%7%41%
2761
August1st to 15thDay
11%6%37%6%45%6%6%7%33%
2490
16th to endDay
10%5%25%5%345%6%8%42%
2483
September1st to 15thDay
12%8%24434446%44%
2134
16th to endDay
10%6%25%425%46%8%43%
1849
October1st to 15thDay
8%14%46%7%345%5%7%32%
1686
16th to endDay
49%37%5%246%8%9%36%
1584
November1st to 15thDay
37%35%5%45%6%7%12%38%
1479
16th to endDay
18%47%7%245%6%11%40%
1266
December1st to 15thDay
16%47%7%36%6%7%12%35%
1260
16th to endDay
5%49%6%5%5%47%11%38%
1344
January1st to 15thNight
5%49%7%45%6%8%12%34%
2685
16th to endNight
6%48%7%45%5%5%10%39%
2703
February1st to 15thNight
16%46%6%45%7%8%12%36%
2415
16th to endNight
17%48%6%46%7%6%8%37%
1953
March1st to 15thNight
447%6%45%5%8%10%40%
2130
16th to endNight
19%5%10%7%35%5%8%11%31%
2067
April1st to 15thNight
6%13%6%7%425%46%8%32%
1726
16th to endNight
5%12%6%9%5%3345%7%34%
1620
May1st to 15thNight
7%11%5%6%5%35%6%6%7%35%
1439
16th to endNight
18%11%36%5%35%5%5%6%28%
1309
June1st to 15thNight
15%8%46%6%34447%33%
1260
16th to endNight
11%7%25%445%6%6%6%40%
1260
July1st to 15thNight
6%6%35%5%2445%8%47%
1260
16th to endNight
5%414435%5%6%8%51%
1406
August1st to 15thNight
9%4244345%5%8%48%
1470
16th to endNight
8%3122135%5%8%54%
1719
September1st to 15thNight
11%7%14313347%50%
1825
16th to endNight
10%4244235%5%7%48%
1856
October1st to 15thNight
7%10%46%5%35%6%6%7%35%
1943
16th to endNight
37%47%5%346%7%10%40%
2288
November1st to 15thNight
16%36%5%35%5%7%10%44%
2368
16th to endNight
16%5%7%6%35%5%7%11%38%
2693
December1st to 15thNight
15%39%7%46%5%7%10%37%
2700
16th to endNight
5%410%7%46%6%7%9%37%
2880

Percentage Cloud Cover SW (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
6%37%5%35%6%7%12%40%
1253
16th to endDay
6%48%6%36%6%6%10%38%
1530
February1st to 15thDay
15%5%8%7%36%7%8%11%34%
1437
16th to endDay
17%5%12%7%47%6%6%10%30%
1521
March1st to 15thDay
6%5%8%6%36%6%8%10%36%
1829
16th to endDay
414%6%11%6%5%6%5%6%8%23%
2153
April1st to 15thDay
8%16%6%7%5%346%7%8%24%
2221
16th to endDay
10%19%5%7%43445%8%27%
2340
May1st to 15thDay
8%15%47%5%35%45%7%29%
2510
16th to endDay
23%12%37%6%35%5%5%6%20%
2802
June1st to 15thDay
20%11%47%6%46%35%7%22%
2700
16th to endDay
15%8%47%6%35%5%6%7%28%
2700
July1st to 15thDay
11%6%36%6%47%6%6%8%33%
2700
16th to endDay
6%5%245%35%7%6%7%44%
2761
August1st to 15thDay
11%7%25%5%35%6%7%8%34%
2490
16th to endDay
10%4244345%6%7%45%
2483
September1st to 15thDay
12%7%15%423335%48%
2134
16th to endDay
10%6%14425%46%8%45%
1849
October1st to 15thDay
9%13%36%7%2436%9%32%
1686
16th to endDay
5%9%36%5%346%8%9%37%
1584
November1st to 15thDay
37%46%5%35%5%6%9%42%
1479
16th to endDay
28%48%6%2445%9%42%
1266
December1st to 15thDay
17%47%7%36%5%8%11%35%
1260
16th to endDay
6%5%10%5%35%5%7%9%40%
1344
January1st to 15thNight
16%39%6%45%6%7%10%36%
2685
16th to endNight
16%47%7%46%5%6%8%40%
2703
February1st to 15thNight
17%37%6%35%6%7%9%39%
2415
16th to endNight
18%48%6%35%6%6%8%38%
1953
March1st to 15thNight
15%47%6%46%5%7%10%40%
2130
16th to endNight
28%6%9%6%35%6%6%9%34%
2070
April1st to 15thNight
6%14%6%7%43337%8%33%
1726
16th to endNight
6%12%6%6%6%3445%8%35%
1620
May1st to 15thNight
7%10%5%6%5%345%6%6%37%
1439
16th to endNight
21%8%26%5%35%46%6%29%
1309
June1st to 15thNight
15%7%47%5%245%46%34%
1260
16th to endNight
12%5%24435%6%6%6%41%
1260
July1st to 15thNight
8%5%246%2435%8%48%
1260
16th to endNight
6%31342446%8%52%
1406
August1st to 15thNight
9%5%14325%45%7%49%
1470
16th to endNight
8%41221346%8%55%
1719
September1st to 15thNight
12%6%13313346%52%
1825
16th to endNight
10%4244235%6%7%49%
1856
October1st to 15thNight
8%10%45%5%35%5%48%37%
1943
16th to endNight
48%36%425%5%6%9%43%
2288
November1st to 15thNight
16%45%5%35%46%9%46%
2368
16th to endNight
27%47%6%345%6%11%40%
2693
December1st to 15thNight
16%5%7%7%36%6%7%9%38%
2700
16th to endNight
6%410%6%46%6%7%8%38%
2880

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
35%13%22%21%5%2
1253
16th to endDay
39%11%18%18%9%2
1530
February1st to 15thDay
38%11%22%18%7%2
1437
16th to endDay
47%11%16%16%7%
1521
March1st to 15thDay
39%13%22%19%5%
1829
16th to endDay
56%11%15%11%3
2153
April1st to 15thDay
54%10%16%11%5%
2221
16th to endDay
55%7%16%14%4
2340
May1st to 15thDay
53%7%15%17%5%
2510
16th to endDay
64%7%12%11%4
2807
June1st to 15thDay
61%9%11%11%6%
2700
16th to endDay
53%9%13%15%6%1
2700
July1st to 15thDay
45%10%15%18%9%1
2541
16th to endDay
37%10%13%22%13%2
2589
August1st to 15thDay
43%11%15%20%7%1
2473
16th to endDay
35%9%14%28%11%1
2483
September1st to 15thDay
38%7%13%22%15%1
2134
16th to endDay
35%9%15%27%10%1
1849
October1st to 15thDay
47%10%14%17%9%
1686
16th to endDay
38%12%19%21%7%
1584
November1st to 15thDay
36%12%22%19%7%
1479
16th to endDay
37%12%20%19%7%3
1266
December1st to 15thDay
40%13%21%16%7%
1260
16th to endDay
38%10%18%21%10%1
1344
January1st to 15thNight
40%14%21%15%6%2
2685
16th to endNight
38%11%16%18%11%3
2703
February1st to 15thNight
38%11%19%19%9%2
2426
16th to endNight
41%10%15%18%12%1
1953
March1st to 15thNight
35%13%24%19%6%
2130
16th to endNight
44%12%19%17%6%
2070
April1st to 15thNight
47%9%17%17%7%
1726
16th to endNight
47%9%17%19%5%1
1620
May1st to 15thNight
44%10%14%24%6%
1440
16th to endNight
53%8%16%15%5%
1309
June1st to 15thNight
49%9%14%18%8%
1260
16th to endNight
39%11%16%23%9%
1260
July1st to 15thNight
35%7%16%29%10%1
1190
16th to endNight
27%9%17%28%15%1
1315
August1st to 15thNight
32%7%17%31%10%1
1462
16th to endNight
24%6%18%34%14%1
1719
September1st to 15thNight
32%418%25%16%2
1825
16th to endNight
32%8%18%26%12%2
1856
October1st to 15thNight
43%10%14%20%10%
1943
16th to endNight
35%11%17%25%9%
2288
November1st to 15thNight
34%12%20%22%10%
2368
16th to endNight
37%13%21%16%8%3
2693
December1st to 15thNight
39%12%19%19%6%1
2700
16th to endNight
40%11%18%20%9%
2880

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
5%6%33%35%10%10%
60
16th to endDay
431%29%21%47%
64
February1st to 15thDay
237%38%13%5%1
67
16th to endDay
423%33%28%9%
180
March1st to 15thDay
8%38%38%12%1
270
16th to endDay
14%33%32%15%2
288
April1st to 15thDay
21%25%32%17%3
269
16th to endDay
30%20%27%14%5%2
270
May1st to 15thDay
19%16%30%21%9%2
339
16th to endDay
28%10%18%19%17%4
517
June1st to 15thDay
22%18%25%20%10%2
495
16th to endDay
16%18%31%20%9%3
495
July1st to 15thDay
16%11%29%23%15%3
475
16th to endDay
11%17%34%22%10%2
430
August1st to 15thDay
18%10%31%26%10%2
315
16th to endDay
16%18%30%25%6%2
332
September1st to 15thDay
20%17%32%20%6%2
315
16th to endDay
18%25%32%18%5%
268
October1st to 15thDay
23%22%29%18%5%
170
16th to endDay
9%17%34%22%9%6%
96
November1st to 15thDay
13%31%38%12%22
90
16th to endDay
11%22%26%13%13%13%
61
December1st to 15thDay
128%28%25%13%3
60
16th to endDay
12%18%32%25%7%3
64
January1st to 15thNight
8%29%42%15%31
900
16th to endNight
6%29%38%18%5%1
783
February1st to 15thNight
5%25%34%20%11%2
704
16th to endNight
6%15%40%25%10%
632
March1st to 15thNight
5%25%42%18%6%1
720
16th to endNight
8%18%36%26%8%1
768
April1st to 15thNight
13%20%28%28%7%2
646
16th to endNight
13%14%30%27%11%2
540
May1st to 15thNight
11%12%25%32%15%2
411
16th to endNight
24%8%19%24%20%2
375
June1st to 15thNight
20%10%23%27%16%1
360
16th to endNight
13%10%26%27%19%1
360
July1st to 15thNight
13%6%20%33%24%1
340
16th to endNight
9%6%21%37%23%1
376
August1st to 15thNight
14%215%33%30%3
390
16th to endNight
11%10%20%35%19%2
573
September1st to 15thNight
16%8%20%26%18%8%
690
16th to endNight
13%16%25%27%10%5%
671
October1st to 15thNight
15%17%28%25%10%2
660
16th to endNight
10%21%34%25%6%2
704
November1st to 15thNight
10%30%41%11%41
793
16th to endNight
8%28%41%16%41
900
December1st to 15thNight
6%25%40%17%8%2
900
16th to endNight
5%28%39%18%6%1
960
Page generated at 2017-09-20 02:49:56. Version ac04

Copyright 2017 A. Danko


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