Doghouse Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Doghouse Observatory clear sky chart from 2005-11-06 to 2024-01-16.

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
20%
23453
13%
74706
5%
23389
29%
23389
14%
54346

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
12%
850
11%
2838
1%
847
23%
847
9%
2122
January11th to 20thNight
15%
823
11%
2638
2%
823
25%
823
9%
2022
January21st to endNight
18%
792
18%
2574
5%
792
33%
792
14%
1778
February1st to 10thNight
14%
720
13%
2340
3%
720
26%
720
12%
1700
February11th to 20thNight
11%
703
12%
2276
2%
700
24%
700
10%
1702
February21st to endNight
18%
592
17%
1922
5%
592
32%
592
14%
1359
March1st to 10thNight
14%
720
16%
1994
4%
720
24%
720
14%
1517
March11th to 20thNight
18%
720
15%
1980
5%
720
27%
720
15%
1501
March21st to endNight
17%
792
15%
2178
4%
792
27%
792
15%
1635
April1st to 10thNight
16%
547
11%
1807
4%
547
23%
547
10%
1384
April11th to 20thNight
21%
534
17%
1671
7%
534
30%
534
16%
1182
April21st to endNight
21%
540
14%
1620
4%
540
30%
540
15%
1207
May1st to 10thNight
25%
540
14%
1531
7%
540
31%
540
16%
1136
May11th to 20thNight
25%
532
15%
1417
5%
532
34%
532
19%
1020
May21st to endNight
19%
583
12%
1551
4%
582
26%
582
21%
1103
June1st to 10thNight
24%
464
9%
1364
5%
464
27%
464
16%
1021
June11th to 20thNight
27%
360
13%
1260
6%
360
35%
360
18%
862
June21st to endNight
26%
360
7%
1260
3%
360
32%
360
15%
915
July1st to 10thNight
27%
350
12%
1225
5%
350
36%
350
21%
787
July11th to 20thNight
33%
414
11%
1284
7%
414
38%
414
21%
865
July21st to endNight
29%
590
11%
1511
7%
558
33%
558
22%
1085
August1st to 10thNight
34%
538
11%
1600
5%
534
40%
534
25%
1048
August11th to 20thNight
36%
532
12%
1596
6%
532
40%
532
22%
1083
August21st to endNight
39%
594
16%
1854
10%
594
45%
594
27%
1156
September1st to 10thNight
30%
540
16%
1800
9%
540
40%
540
24%
1117
September11th to 20thNight
35%
610
20%
1870
13%
610
44%
610
23%
1209
September21st to endNight
28%
720
20%
2034
9%
720
38%
720
24%
1337
October1st to 10thNight
29%
720
18%
2160
9%
720
36%
720
21%
1456
October11th to 20thNight
23%
720
17%
2160
6%
720
33%
720
18%
1512
October21st to endNight
16%
796
14%
2386
5%
796
26%
796
12%
1802
November1st to 10thNight
17%
830
12%
2593
4%
830
25%
830
11%
1959
November11th to 20thNight
17%
850
14%
2660
5%
850
27%
850
11%
2003
November21st to endNight
14%
850
10%
2660
2%
850
22%
850
9%
2061
December1st to 10thNight
12%
850
11%
2660
1%
850
21%
850
8%
2151
December11th to 20thNight
7%
850
10%
3242
1%
849
15%
849
5%
2648
December21st to endNight
10%
927
6%
5190
1%
907
21%
907
4%
3901

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
19%10%47%6%3445%7%32%
74849
Night
20%11%47%6%3445%6%31%
74947
TransparencyDay
53%5%12%20%9%1
74544
Night
55%5%11%19%9%1
74787
SeeingDay
26%16%33%19%6%1
15820
Night
26%16%32%21%6%
23461

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 10thDay
17%17%6%10%6%33345%27%
1327
11th to 20thDay
19%13%6%12%7%3444425%
1441
21st to endDay
11%11%47%8%35%45%7%35%
1782
February1st to 10thDay
16%13%5%8%6%35%445%31%
1620
11th to 20thDay
17%13%410%6%35%5%46%27%
1573
21st to endDay
10%13%6%7%6%35%36%8%34%
1333
March1st to 10thDay
16%15%6%8%6%245%5%5%28%
1962
11th to 20thDay
14%12%7%11%5%3445%6%29%
1980
21st to endDay
19%14%6%8%5%34435%29%
2178
April1st to 10thDay
21%12%5%8%6%35%446%27%
2151
11th to 20thDay
20%12%35%5%35%447%32%
2235
21st to endDay
22%11%36%435%45%7%28%
2340
May1st to 10thDay
26%9%38%6%3445%6%27%
2426
11th to 20thDay
23%9%25%42445%6%35%
2478
21st to endDay
20%9%36%5%3445%8%32%
2724
June1st to 10thDay
27%9%26%6%345%5%6%26%
2610
11th to 20thDay
20%7%37%6%445%6%6%33%
2700
21st to endDay
25%8%37%5%34447%30%
2700
July1st to 10thDay
17%6%35%6%35%6%6%9%36%
2700
11th to 20thDay
13%6%36%6%45%6%7%10%35%
2615
21st to endDay
15%7%37%7%46%6%6%9%31%
2716
August1st to 10thDay
16%6%25%5%45%5%6%9%37%
2327
11th to 20thDay
15%5%36%6%45%6%7%9%34%
2304
21st to endDay
13%6%35%5%345%6%8%43%
2502
September1st to 10thDay
17%5%24325%5%5%8%42%
2160
11th to 20thDay
19%7%36%43345%7%39%
2088
21st to endDay
20%5%244235%5%6%42%
1926
October1st to 10thDay
19%7%36%5%2445%8%37%
1800
11th to 20thDay
19%11%35%5%35%5%47%32%
1800
21st to endDay
22%10%26%6%45%446%29%
1969
November1st to 10thDay
19%13%49%5%44446%29%
1485
11th to 20thDay
19%13%46%6%35%5%46%30%
1520
21st to endDay
18%15%5%7%7%3445%5%26%
1520
December1st to 10thDay
23%15%48%6%35%445%23%
1520
11th to 20thDay
19%18%6%10%6%4434423%
1906
21st to endDay
19%14%7%12%6%34345%23%
2431
January1st to 10thNight
17%15%5%8%6%4445%5%27%
2838
11th to 20thNight
17%13%5%8%7%4445%5%26%
2638
21st to endNight
13%11%5%7%6%345%5%6%33%
2574
February1st to 10thNight
17%12%48%6%4445%6%29%
2340
11th to 20thNight
18%14%49%7%35%446%26%
2273
21st to endNight
13%13%5%9%6%35%5%5%5%32%
1922
March1st to 10thNight
18%13%49%7%35%345%28%
1985
11th to 20thNight
17%12%6%7%7%44445%30%
1979
21st to endNight
20%14%5%8%424335%31%
2178
April1st to 10thNight
23%12%47%6%35%44426%
1807
11th to 20thNight
22%11%36%6%34335%33%
1671
21st to endNight
23%12%47%5%34345%29%
1620
May1st to 10thNight
26%8%36%5%345%5%5%30%
1531
11th to 20thNight
23%10%35%5%34346%35%
1416
21st to endNight
18%7%27%5%445%5%8%35%
1550
June1st to 10thNight
27%7%35%5%35%46%8%26%
1364
11th to 20thNight
22%7%35%5%345%5%6%35%
1260
21st to endNight
22%10%46%5%345%5%6%31%
1260
July1st to 10thNight
17%8%35%6%435%5%9%35%
1260
11th to 20thNight
14%7%36%6%35%7%7%10%32%
1326
21st to endNight
15%7%37%8%36%45%8%32%
1599
August1st to 10thNight
14%436%6%35%6%7%7%39%
1612
11th to 20thNight
15%8%27%6%46%5%6%8%34%
1596
21st to endNight
15%5%25%5%345%6%10%40%
1854
September1st to 10thNight
16%6%25%43445%7%44%
1800
11th to 20thNight
17%6%26%5%2435%6%43%
1870
21st to endNight
18%6%25%5%3435%6%42%
2034
October1st to 10thNight
20%7%36%5%24445%39%
2160
11th to 20thNight
19%7%36%5%35%46%6%35%
2160
21st to endNight
27%8%36%5%4435%5%29%
2386
November1st to 10thNight
21%14%36%5%3445%5%30%
2593
11th to 20thNight
19%11%48%6%35%446%29%
2660
21st to endNight
22%14%37%6%3445%5%27%
2660
December1st to 10thNight
23%14%5%8%6%4445%5%22%
2660
11th to 20thNight
23%17%6%9%6%2434323%
3293
21st to endNight
24%14%5%10%5%3334425%
5218

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
62%5%9%13%10%1
1328
11th to 20thDay
65%5%7%13%9%1
1441
21st to endDay
51%410%18%16%1
1782
February1st to 10thDay
57%311%17%12%1
1620
11th to 20thDay
60%39%18%9%1
1581
21st to endDay
50%412%20%13%2
1333
March1st to 10thDay
58%29%20%9%1
1966
11th to 20thDay
57%410%18%9%2
1980
21st to endDay
59%39%17%9%3
2178
April1st to 10thDay
59%38%17%10%3
2151
11th to 20thDay
52%410%21%12%1
2235
21st to endDay
55%411%17%11%2
2340
May1st to 10thDay
58%49%17%11%1
2426
11th to 20thDay
51%39%25%11%
2482
21st to endDay
51%6%14%21%8%1
2724
June1st to 10thDay
58%412%20%6%
2610
11th to 20thDay
51%412%23%9%1
2700
21st to endDay
55%5%13%18%9%1
2700
July1st to 10thDay
42%5%18%25%9%
2625
11th to 20thDay
43%5%19%24%9%1
2534
21st to endDay
48%6%17%22%7%
2564
August1st to 10thDay
42%6%17%28%7%
2314
11th to 20thDay
44%7%17%25%6%
2304
21st to endDay
39%5%17%29%11%
2502
September1st to 10thDay
39%5%18%26%13%
2160
11th to 20thDay
45%412%25%13%1
2088
21st to endDay
43%411%28%14%1
1926
October1st to 10thDay
47%412%27%10%1
1800
11th to 20thDay
53%5%13%22%7%1
1800
21st to endDay
57%5%11%19%9%
1969
November1st to 10thDay
57%5%10%19%9%
1485
11th to 20thDay
56%7%12%14%10%1
1520
21st to endDay
59%8%12%14%7%
1520
December1st to 10thDay
66%7%9%13%5%
1520
11th to 20thDay
67%6%7%13%7%1
1905
21st to endDay
66%6%12%10%5%1
2431
January1st to 10thNight
59%5%10%18%8%1
2838
11th to 20thNight
61%6%11%13%9%1
2638
21st to endNight
51%5%10%22%10%2
2574
February1st to 10thNight
56%410%15%12%2
2340
11th to 20thNight
60%38%15%11%1
2276
21st to endNight
54%48%18%14%2
1922
March1st to 10thNight
59%38%17%11%2
1994
11th to 20thNight
57%47%19%10%3
1980
21st to endNight
57%47%18%12%2
2178
April1st to 10thNight
61%5%8%13%10%3
1807
11th to 20thNight
54%38%20%13%1
1671
21st to endNight
58%39%17%12%1
1620
May1st to 10thNight
55%5%9%19%10%2
1531
11th to 20thNight
51%410%23%11%1
1417
21st to endNight
48%5%15%21%9%1
1551
June1st to 10thNight
57%412%19%8%
1364
11th to 20thNight
50%5%10%24%10%1
1260
21st to endNight
55%6%14%15%10%1
1260
July1st to 10thNight
46%5%17%26%7%
1225
11th to 20thNight
45%7%15%23%9%
1284
21st to endNight
50%5%18%20%7%
1511
August1st to 10thNight
42%6%18%26%8%
1600
11th to 20thNight
47%5%19%24%5%
1596
21st to endNight
39%5%19%28%9%
1854
September1st to 10thNight
41%5%12%31%11%
1800
11th to 20thNight
44%412%27%13%1
1870
21st to endNight
44%411%28%14%1
2034
October1st to 10thNight
47%5%11%26%12%
2160
11th to 20thNight
48%6%13%26%6%
2160
21st to endNight
58%5%10%16%11%
2386
November1st to 10thNight
59%5%10%16%9%1
2593
11th to 20thNight
57%7%10%16%10%1
2660
21st to endNight
59%8%12%14%6%
2660
December1st to 10thNight
64%8%8%14%5%
2660
11th to 20thNight
67%6%6%15%7%
3295
21st to endNight
64%6%12%12%6%1
5218

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
29%23%36%10%2
180
11th to 20thDay
26%23%32%14%4
303
21st to endDay
18%22%39%17%31
374
February1st to 10thDay
29%22%33%14%21
340
11th to 20thDay
28%24%32%13%3
336
21st to endDay
20%22%36%18%41
280
March1st to 10thDay
27%20%37%12%3
414
11th to 20thDay
23%22%35%15%41
420
21st to endDay
29%22%33%13%31
462
April1st to 10thDay
32%25%31%9%2
420
11th to 20thDay
29%23%28%15%41
412
21st to endDay
31%16%31%16%5%
420
May1st to 10thDay
36%14%28%17%41
509
11th to 20thDay
27%14%31%20%8%1
624
21st to endDay
27%15%34%20%41
680
June1st to 10thDay
36%10%30%18%6%1
630
11th to 20thDay
25%11%35%21%7%1
630
21st to endDay
27%6%33%26%6%2
630
July1st to 10thDay
20%7%40%23%8%1
620
11th to 20thDay
18%5%37%29%10%2
618
21st to endDay
19%6%36%28%9%1
656
August1st to 10thDay
15%6%35%33%11%1
446
11th to 20thDay
18%7%33%26%14%2
439
21st to endDay
17%11%30%29%9%3
495
September1st to 10thDay
15%11%42%21%9%2
450
11th to 20thDay
24%16%29%23%6%2
450
21st to endDay
24%13%34%19%8%3
423
October1st to 10thDay
23%14%33%18%11%2
360
11th to 20thDay
25%18%30%20%6%2
360
21st to endDay
27%23%28%18%41
396
November1st to 10thDay
30%21%30%13%5%1
365
11th to 20thDay
30%23%32%11%41
370
21st to endDay
32%23%29%12%3
370
December1st to 10thDay
35%19%29%13%3
370
11th to 20thDay
33%29%29%8%1
370
21st to endDay
22%31%34%12%2
198
January1st to 10thNight
26%21%32%17%4
850
11th to 20thNight
25%21%32%18%4
823
21st to endNight
20%22%33%19%5%1
792
February1st to 10thNight
25%21%33%17%3
720
11th to 20thNight
29%22%32%13%41
703
21st to endNight
23%18%35%18%5%1
592
March1st to 10thNight
25%18%37%17%3
720
11th to 20thNight
24%18%30%21%6%1
720
21st to endNight
28%16%30%19%6%1
792
April1st to 10thNight
32%17%29%19%3
547
11th to 20thNight
29%13%31%21%6%1
534
21st to endNight
31%12%29%18%8%1
540
May1st to 10thNight
30%12%28%24%6%1
540
11th to 20thNight
28%12%27%25%7%1
532
21st to endNight
22%15%39%21%3
583
June1st to 10thNight
32%8%31%24%5%
464
11th to 20thNight
26%8%34%26%7%1
360
21st to endNight
25%5%33%29%8%1
360
July1st to 10thNight
21%6%40%24%9%1
350
11th to 20thNight
16%7%38%31%7%
414
21st to endNight
18%5%36%32%9%
590
August1st to 10thNight
16%439%29%11%1
538
11th to 20thNight
18%6%31%32%12%1
532
21st to endNight
17%7%31%32%13%1
594
September1st to 10thNight
19%9%38%24%9%1
540
11th to 20thNight
23%9%27%30%10%1
610
21st to endNight
22%14%33%23%8%
720
October1st to 10thNight
24%11%30%24%10%
720
11th to 20thNight
23%13%37%19%8%1
720
21st to endNight
31%20%28%17%3
796
November1st to 10thNight
32%18%27%17%5%1
830
11th to 20thNight
30%21%26%17%5%1
850
21st to endNight
31%22%28%15%3
850
December1st to 10thNight
33%18%29%16%3
850
11th to 20thNight
30%24%31%11%3
850
21st to endNight
30%23%28%15%31
935
Page generated at 2024-01-13 20:28:31. Version ac07

Copyright 2024 Attilla Danko


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