Dogwood Ridge Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dogwood Ridge Observatory clear sky chart from 2005-11-06 to 2024-01-14.

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
41%
23769
22%
74673
13%
23720
51%
23720
26%
46146

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 10thNight
24%
757
25%
2459
9%
757
43%
757
24%
1503
January11th to 20thNight
25%
735
24%
2386
10%
735
43%
735
20%
1537
January21st to endNight
24%
792
27%
2574
12%
792
44%
792
26%
1544
February1st to 10thNight
28%
720
20%
2340
10%
720
42%
720
23%
1451
February11th to 20thNight
17%
701
21%
2268
7%
699
35%
699
20%
1443
February21st to endNight
22%
592
28%
1709
10%
592
41%
592
25%
1098
March1st to 10thNight
27%
720
27%
1980
11%
720
42%
720
30%
1200
March11th to 20thNight
25%
720
21%
1980
10%
720
36%
720
24%
1308
March21st to endNight
28%
792
21%
2178
8%
792
40%
792
25%
1437
April1st to 10thNight
28%
720
22%
1829
6%
720
38%
720
29%
1194
April11th to 20thNight
35%
711
23%
1775
8%
711
43%
711
35%
1114
April21st to endNight
40%
720
23%
1800
10%
720
46%
720
33%
1175
May1st to 10thNight
36%
549
19%
1629
8%
549
44%
549
26%
1044
May11th to 20thNight
46%
531
16%
1593
10%
531
50%
531
25%
1048
May21st to endNight
55%
458
16%
1620
16%
458
58%
458
24%
1020
June1st to 10thNight
62%
360
21%
1440
23%
360
67%
360
27%
802
June11th to 20thNight
56%
360
16%
1440
17%
360
59%
360
23%
853
June21st to endNight
61%
360
20%
1440
22%
360
67%
360
27%
806
July1st to 10thNight
63%
461
15%
1511
14%
461
64%
461
25%
960
July11th to 20thNight
73%
522
16%
1566
12%
522
75%
522
33%
934
July21st to endNight
65%
591
18%
1672
14%
558
67%
558
31%
1036
August1st to 10thNight
64%
537
17%
1600
13%
534
65%
534
28%
1041
August11th to 20thNight
61%
570
18%
1634
13%
570
62%
570
26%
1104
August21st to endNight
60%
792
17%
1980
11%
792
62%
792
31%
1343
September1st to 10thNight
61%
720
23%
1800
15%
720
63%
720
33%
1190
September11th to 20thNight
62%
720
27%
1860
22%
720
64%
720
34%
1198
September21st to endNight
46%
720
20%
2047
16%
720
52%
720
25%
1396
October1st to 10thNight
52%
720
23%
2160
21%
720
58%
720
30%
1336
October11th to 20thNight
45%
720
27%
2160
21%
720
55%
720
29%
1313
October21st to endNight
42%
792
30%
2376
20%
792
56%
792
33%
1377
November1st to 10thNight
44%
740
28%
2221
19%
740
55%
740
31%
1316
November11th to 20thNight
36%
760
27%
2465
15%
760
51%
760
28%
1429
November21st to endNight
39%
760
25%
2660
17%
760
53%
760
29%
1478
December1st to 10thNight
29%
760
22%
2660
10%
760
45%
760
21%
1647
December11th to 20thNight
35%
760
24%
3172
14%
758
51%
758
22%
1832
December21st to endNight
32%
826
16%
4689
13%
817
46%
817
14%
2639

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%5%25%5%35%5%6%8%43%
74614
Night
14%6%25%5%35%45%7%44%
75125
TransparencyDay
39%411%24%17%4
74335
Night
40%410%23%18%4
74923
SeeingDay
19%10%25%25%15%6%
13924
Night
17%8%26%32%15%2
23786

By Month

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 10thDay
16%6%345%345%5%5%46%
1706
11th to 20thDay
17%6%36%5%34346%42%
1647
21st to endDay
16%7%24425%5%47%43%
1782
February1st to 10thDay
13%8%35%5%35%6%6%7%40%
1620
11th to 20thDay
20%5%25%5%2345%5%44%
1577
21st to endDay
18%8%26%5%345%47%37%
1542
March1st to 10thDay
14%5%25%423347%51%
1980
11th to 20thDay
18%5%25%5%35%45%7%40%
1980
21st to endDay
17%6%37%6%34447%39%
2178
April1st to 10thDay
11%5%245%345%5%7%51%
2130
11th to 20thDay
12%5%25%4345%5%6%49%
2134
21st to endDay
18%5%25%5%445%5%7%42%
2166
May1st to 10thDay
14%6%25%436%5%6%8%40%
2340
11th to 20thDay
17%5%35%6%45%5%6%8%36%
2301
21st to endDay
14%435%5%35%5%5%10%40%
2651
June1st to 10thDay
10%4245%45%5%7%10%44%
2520
11th to 20thDay
11%426%5%45%6%8%10%40%
2520
21st to endDay
8%4245%46%6%8%11%43%
2520
July1st to 10thDay
10%435%5%46%6%7%10%41%
2397
11th to 20thDay
6%325%6%46%7%8%12%41%
2340
21st to endDay
9%5%25%7%46%7%7%11%37%
2547
August1st to 10thDay
11%5%36%6%46%7%7%10%36%
2327
11th to 20thDay
12%6%35%6%46%6%8%9%35%
2248
21st to endDay
10%5%25%6%35%6%6%10%43%
2376
September1st to 10thDay
12%435%5%345%5%7%46%
2160
11th to 20thDay
12%5%35%43446%8%46%
2097
21st to endDay
21%5%345%3446%6%38%
1913
October1st to 10thDay
15%5%25%424445%50%
1800
11th to 20thDay
16%42443445%5%51%
1800
21st to endDay
14%5%35%32335%5%53%
1980
November1st to 10thDay
13%423434436%55%
1857
11th to 20thDay
15%5%2442445%6%51%
1710
21st to endDay
15%41342445%6%51%
1520
December1st to 10thDay
17%7%33435%47%7%41%
1520
11th to 20thDay
17%5%23423345%51%
1910
21st to endDay
19%6%35%6%2445%7%39%
2818
January1st to 10thNight
16%6%25%434446%46%
2459
11th to 20thNight
17%7%35%5%35%446%41%
2386
21st to endNight
15%6%34435%445%48%
2574
February1st to 10thNight
15%7%25%43446%7%42%
2340
11th to 20thNight
20%7%235%34345%43%
2268
21st to endNight
17%6%34325%45%6%45%
1709
March1st to 10thNight
13%424424446%51%
1980
11th to 20thNight
19%6%25%43446%8%40%
1980
21st to endNight
16%6%36%4245%46%44%
2178
April1st to 10thNight
15%5%245%2445%7%46%
1829
11th to 20thNight
12%5%25%42345%9%49%
1775
21st to endNight
16%5%2343446%7%45%
1800
May1st to 10thNight
15%6%35%43445%8%42%
1629
11th to 20thNight
17%6%34435%5%6%9%37%
1592
21st to endNight
14%5%25%6%45%5%5%8%41%
1620
June1st to 10thNight
11%5%15%435%5%8%9%44%
1440
11th to 20thNight
9%6%25%6%36%5%7%8%42%
1440
21st to endNight
8%425%5%35%5%7%10%45%
1440
July1st to 10thNight
10%5%35%6%45%5%5%9%42%
1556
11th to 20thNight
5%425%5%46%7%9%11%43%
1620
21st to endNight
7%426%6%47%6%8%11%39%
1771
August1st to 10thNight
10%5%26%6%36%6%8%9%39%
1611
11th to 20thNight
12%6%37%5%36%7%6%8%36%
1634
21st to endNight
9%7%36%6%5%5%6%6%10%38%
1980
September1st to 10thNight
13%5%25%445%46%7%45%
1800
11th to 20thNight
12%5%25%5%35%5%6%7%45%
1860
21st to endNight
22%7%3442445%6%39%
2047
October1st to 10thNight
17%5%35%334346%47%
2160
11th to 20thNight
16%425%42445%6%48%
2160
21st to endNight
14%42342445%6%52%
2376
November1st to 10thNight
13%5%25%434235%53%
2221
11th to 20thNight
13%5%245%34446%50%
2465
21st to endNight
13%424435%45%6%51%
2660
December1st to 10thNight
16%8%35%5%3445%5%43%
2660
11th to 20thNight
17%6%2442345%5%47%
3285
21st to endNight
17%6%25%435%5%6%7%41%
4820

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 10thDay
40%39%23%19%6%
1707
11th to 20thDay
45%29%22%19%3
1647
21st to endDay
41%38%24%19%5%
1782
February1st to 10thDay
44%410%25%14%4
1620
11th to 20thDay
43%37%22%21%5%
1586
21st to endDay
48%410%15%17%6%
1542
March1st to 10thDay
36%39%24%22%6%
1980
11th to 20thDay
43%410%19%17%7%
1980
21st to endDay
46%49%20%16%5%
2178
April1st to 10thDay
34%311%24%20%9%
2130
11th to 20thDay
36%410%21%22%6%
2134
21st to endDay
43%410%23%15%5%
2166
May1st to 10thDay
41%5%14%21%16%3
2340
11th to 20thDay
44%6%15%22%11%2
2305
21st to endDay
40%6%14%26%13%
2651
June1st to 10thDay
35%6%16%26%16%1
2520
11th to 20thDay
38%7%16%22%16%2
2520
21st to endDay
33%7%16%28%15%1
2520
July1st to 10thDay
38%7%14%21%17%3
2332
11th to 20thDay
33%6%18%26%15%2
2271
21st to endDay
39%7%13%26%14%1
2405
August1st to 10thDay
42%6%15%26%10%1
2314
11th to 20thDay
42%7%15%23%12%1
2248
21st to endDay
36%5%17%26%13%3
2376
September1st to 10thDay
38%414%19%20%4
2160
11th to 20thDay
36%5%7%27%20%4
2097
21st to endDay
46%48%20%19%3
1913
October1st to 10thDay
37%48%27%20%4
1800
11th to 20thDay
36%38%26%23%4
1800
21st to endDay
36%26%27%23%6%
1980
November1st to 10thDay
33%37%23%28%5%
1857
11th to 20thDay
35%39%23%22%8%
1710
21st to endDay
35%38%25%24%5%
1520
December1st to 10thDay
42%311%24%15%5%
1520
11th to 20thDay
37%27%29%17%8%
1906
21st to endDay
46%29%27%14%1
2818
January1st to 10thNight
40%38%21%21%7%
2459
11th to 20thNight
45%48%20%18%4
2386
21st to endNight
39%27%25%22%4
2574
February1st to 10thNight
41%410%25%17%3
2340
11th to 20thNight
45%27%20%19%7%
2270
21st to endNight
42%29%22%19%7%
1709
March1st to 10thNight
34%48%25%23%5%
1980
11th to 20thNight
42%48%21%20%4
1980
21st to endNight
42%5%9%21%17%6%
2178
April1st to 10thNight
39%49%19%22%7%
1829
11th to 20thNight
34%312%21%23%6%
1775
21st to endNight
38%411%24%17%6%
1800
May1st to 10thNight
41%413%23%14%4
1629
11th to 20thNight
44%5%14%22%13%3
1593
21st to endNight
42%6%15%25%12%1
1621
June1st to 10thNight
35%5%13%29%16%1
1440
11th to 20thNight
38%7%17%21%15%2
1440
21st to endNight
34%6%15%24%17%4
1440
July1st to 10thNight
41%6%16%17%15%4
1511
11th to 20thNight
31%8%21%25%12%2
1566
21st to endNight
36%7%17%27%13%1
1672
August1st to 10thNight
40%7%18%24%11%1
1600
11th to 20thNight
43%7%15%22%12%1
1634
21st to endNight
41%6%16%23%11%3
1980
September1st to 10thNight
38%5%13%22%16%6%
1800
11th to 20thNight
37%5%10%25%20%3
1860
21st to endNight
46%5%8%21%16%4
2047
October1st to 10thNight
39%48%26%20%4
2160
11th to 20thNight
38%36%24%23%5%
2160
21st to endNight
34%37%25%24%6%
2376
November1st to 10thNight
36%37%22%26%6%
2221
11th to 20thNight
37%37%21%25%8%
2465
21st to endNight
35%39%25%22%6%
2660
December1st to 10thNight
44%38%24%17%4
2660
11th to 20thNight
40%39%21%21%7%
3288
21st to endNight
44%210%25%17%2
4820

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 10thDay
25%20%30%20%4
270
11th to 20thDay
28%24%33%13%2
249
21st to endDay
28%22%34%12%4
264
February1st to 10thDay
27%20%38%11%4
240
11th to 20thDay
38%22%31%9%
244
21st to endDay
30%15%31%21%3
346
March1st to 10thDay
23%18%31%23%5%
420
11th to 20thDay
23%19%33%18%6%1
420
21st to endDay
23%15%36%20%6%1
462
April1st to 10thDay
21%17%31%20%9%1
420
11th to 20thDay
18%15%30%20%11%6%
412
21st to endDay
26%11%30%22%9%2
420
May1st to 10thDay
21%15%29%24%9%3
423
11th to 20thDay
21%7%29%28%12%4
447
21st to endDay
19%421%30%21%5%
485
June1st to 10thDay
13%6%24%29%24%5%
450
11th to 20thDay
14%7%23%30%16%10%
450
21st to endDay
11%423%34%20%8%
450
July1st to 10thDay
12%217%29%28%12%
445
11th to 20thDay
7%214%35%31%12%
444
21st to endDay
11%418%31%22%14%
488
August1st to 10thDay
14%316%26%29%12%
446
11th to 20thDay
13%315%27%28%15%
439
21st to endDay
11%216%29%25%16%
495
September1st to 10thDay
15%415%27%21%18%
450
11th to 20thDay
15%312%35%23%11%
450
21st to endDay
27%5%20%28%15%5%
450
October1st to 10thDay
20%5%22%28%19%7%
450
11th to 20thDay
16%9%24%28%20%3
450
21st to endDay
17%11%32%26%11%3
495
November1st to 10thDay
17%10%25%31%13%4
455
11th to 20thDay
19%13%30%24%12%2
342
21st to endDay
18%17%29%26%8%2
180
December1st to 10thDay
23%13%39%17%7%2
180
11th to 20thDay
26%13%31%21%7%2
180
21st to endDay
28%15%30%17%9%1
213
January1st to 10thNight
19%13%38%26%3
760
11th to 20thNight
21%12%35%28%4
735
21st to endNight
18%13%41%26%3
792
February1st to 10thNight
19%12%36%31%3
720
11th to 20thNight
25%14%39%21%1
703
21st to endNight
23%14%36%24%3
592
March1st to 10thNight
17%15%37%26%5%
720
11th to 20thNight
22%15%33%24%5%1
720
21st to endNight
20%11%35%28%6%
792
April1st to 10thNight
17%14%38%26%6%
720
11th to 20thNight
14%12%34%30%10%
711
21st to endNight
18%8%29%36%9%
720
May1st to 10thNight
19%9%30%30%13%
549
11th to 20thNight
20%321%37%17%1
531
21st to endNight
17%116%40%23%3
460
June1st to 10thNight
10%217%45%24%1
360
11th to 20thNight
12%416%39%27%1
360
21st to endNight
9%217%50%20%2
360
July1st to 10thNight
11%212%36%33%5%
461
11th to 20thNight
7%110%41%36%6%
522
21st to endNight
8%214%42%28%5%
591
August1st to 10thNight
14%19%39%33%4
537
11th to 20thNight
15%29%36%34%4
570
21st to endNight
12%212%36%33%5%
792
September1st to 10thNight
17%210%32%33%7%
720
11th to 20thNight
13%314%34%31%4
720
21st to endNight
25%317%31%22%2
720
October1st to 10thNight
19%418%32%23%4
720
11th to 20thNight
18%7%24%33%17%1
720
21st to endNight
16%7%29%34%13%1
792
November1st to 10thNight
16%7%25%36%14%1
740
11th to 20thNight
17%9%31%31%11%
760
21st to endNight
14%9%32%33%11%
760
December1st to 10thNight
21%10%33%28%8%
760
11th to 20thNight
18%9%31%36%6%
760
21st to endNight
20%10%30%36%3
836
Page generated at 2024-01-11 04:22:37. Version ac07

Copyright 2024 Attilla Danko


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