Bearcat Observatory
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bearcat Observatory clear sky chart from 2005-11-06 to 2024-02-15.

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
39%
24723
21%
80141
12%
24618
47%
24618
26%
50213

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
28%
941
15%
4112
9%
926
39%
926
15%
2965
January11th to 20thNight
24%
950
21%
4018
7%
930
35%
930
15%
2612
January21st to endNight
24%
1034
11%
4504
6%
1023
33%
1023
13%
3310
February1st to 10thNight
25%
950
16%
2470
6%
950
30%
950
23%
1724
February11th to 20thNight
27%
901
19%
2333
7%
897
34%
897
28%
1560
February21st to endNight
23%
602
23%
1786
6%
602
37%
602
25%
1140
March1st to 10thNight
28%
540
23%
1980
12%
540
42%
540
25%
1153
March11th to 20thNight
31%
540
20%
1980
12%
540
42%
540
20%
1243
March21st to endNight
21%
594
11%
2178
6%
594
29%
594
13%
1563
April1st to 10thNight
29%
540
20%
1872
12%
540
42%
540
26%
1085
April11th to 20thNight
28%
533
21%
1775
12%
533
42%
533
23%
1109
April21st to endNight
30%
540
21%
1626
13%
540
43%
540
24%
1068
May1st to 10thNight
35%
540
16%
1620
11%
540
44%
540
22%
1092
May11th to 20thNight
39%
531
19%
1594
13%
531
47%
531
28%
1009
May21st to endNight
45%
584
16%
1584
10%
582
51%
582
30%
1031
June1st to 10thNight
62%
540
22%
1440
12%
540
67%
540
43%
821
June11th to 20thNight
58%
540
21%
1440
11%
540
61%
540
43%
832
June21st to endNight
56%
540
22%
1440
11%
540
61%
540
48%
803
July1st to 10thNight
70%
525
19%
1449
13%
525
71%
525
44%
813
July11th to 20thNight
71%
522
21%
1566
17%
522
74%
522
45%
812
July21st to endNight
71%
591
25%
1673
23%
558
75%
558
44%
891
August1st to 10thNight
66%
537
21%
1601
21%
534
70%
534
41%
886
August11th to 20thNight
68%
534
28%
1600
31%
534
71%
534
41%
869
August21st to endNight
69%
594
28%
1898
30%
594
73%
594
41%
974
September1st to 10thNight
60%
540
26%
1800
25%
540
67%
540
36%
972
September11th to 20thNight
59%
540
30%
1952
28%
540
66%
540
35%
1014
September21st to endNight
51%
540
29%
1980
23%
540
62%
540
36%
998
October1st to 10thNight
45%
715
24%
2155
17%
715
50%
715
34%
1254
October11th to 20thNight
33%
720
26%
2160
12%
720
44%
720
33%
1258
October21st to endNight
32%
792
25%
2376
12%
792
42%
792
29%
1426
November1st to 10thNight
41%
792
30%
2272
14%
792
54%
792
39%
1247
November11th to 20thNight
30%
950
26%
2611
9%
950
44%
950
33%
1574
November21st to endNight
32%
950
22%
2660
9%
950
42%
950
30%
1667
December1st to 10thNight
30%
950
19%
2660
7%
950
40%
950
27%
1724
December11th to 20thNight
27%
948
21%
3136
7%
948
36%
948
21%
1957
December21st to endNight
23%
1043
12%
4840
7%
1026
35%
1026
11%
3757

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
12%8%36%6%345%5%7%42%
78450
Night
11%7%36%5%3445%7%45%
80683
TransparencyDay
42%6%13%24%14%2
78171
Night
39%6%12%25%16%3
80483
SeeingDay
14%9%29%28%15%4
14686
Night
14%9%33%32%11%1
24748

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
11%11%411%11%45%5%5%6%27%
2818
11th to 20thDay
9%13%5%8%7%38%446%33%
2850
21st to endDay
12%13%6%14%9%5%5%345%24%
3135
February1st to 10thDay
11%11%48%7%45%5%5%7%33%
1710
11th to 20thDay
11%8%5%7%4445%7%8%38%
1610
21st to endDay
12%10%36%6%3445%7%39%
1485
March1st to 10thDay
13%10%5%6%6%24445%41%
1980
11th to 20thDay
17%11%47%5%23447%37%
1980
21st to endDay
20%14%37%5%345%5%6%28%
2178
April1st to 10thDay
16%8%35%5%23446%43%
2087
11th to 20thDay
16%8%36%6%235%5%7%38%
2134
21st to endDay
21%7%25%434447%37%
2330
May1st to 10thDay
16%7%47%6%35%5%6%7%35%
2340
11th to 20thDay
15%7%35%6%445%5%6%40%
2302
21st to endDay
15%8%36%6%445%5%8%36%
2691
June1st to 10thDay
7%5%25%6%346%6%9%48%
2520
11th to 20thDay
7%5%345%345%6%9%48%
2520
21st to endDay
8%5%245%36%6%6%9%46%
2520
July1st to 10thDay
8%424435%6%7%10%47%
2464
11th to 20thDay
7%424435%5%6%9%51%
2340
21st to endDay
6%425%4345%7%10%49%
2546
August1st to 10thDay
8%5%25%6%35%6%7%9%43%
2328
11th to 20thDay
10%4244346%6%9%48%
2301
21st to endDay
8%5%36%5%34446%52%
2458
September1st to 10thDay
12%5%245%3345%6%52%
2160
11th to 20thDay
10%42443445%8%52%
2004
21st to endDay
11%42442345%6%56%
1967
October1st to 10thDay
14%6%35%423446%49%
1800
11th to 20thDay
13%8%33422435%54%
1800
21st to endDay
13%8%35%4235%5%5%46%
1980
November1st to 10thDay
9%6%25%43335%8%53%
1803
11th to 20thDay
11%8%36%5%24346%48%
1568
21st to endDay
15%8%46%32345%6%42%
1520
December1st to 10thDay
9%7%37%7%345%5%7%44%
1520
11th to 20thDay
11%10%48%7%3446%6%38%
1918
21st to endDay
18%12%6%13%7%34445%23%
2783
January1st to 10thNight
8%8%5%15%10%5%5%5%5%6%30%
4135
11th to 20thNight
10%10%5%7%5%38%5%7%5%36%
4120
21st to endNight
13%14%5%12%6%44445%30%
4532
February1st to 10thNight
13%9%48%5%35%45%6%38%
2470
11th to 20thNight
11%8%46%5%345%5%6%43%
2332
21st to endNight
10%8%46%5%3445%5%45%
1786
March1st to 10thNight
11%7%35%5%3335%6%49%
1980
11th to 20thNight
16%7%36%43445%6%43%
1980
21st to endNight
22%10%36%5%35%45%7%29%
2178
April1st to 10thNight
10%7%25%33445%7%49%
1872
11th to 20thNight
13%8%26%43345%5%46%
1775
21st to endNight
15%9%35%433445%44%
1626
May1st to 10thNight
14%7%37%43445%8%40%
1620
11th to 20thNight
13%6%145%34449%47%
1593
21st to endNight
10%7%27%5%4445%8%46%
1583
June1st to 10thNight
5%2234246%6%9%56%
1440
11th to 20thNight
6%323325%6%8%11%52%
1440
21st to endNight
5%3133245%6%10%58%
1440
July1st to 10thNight
7%3233245%7%10%55%
1491
11th to 20thNight
432342435%9%60%
1620
21st to endNight
5%323435%47%10%54%
1772
August1st to 10thNight
5%325%4345%6%11%53%
1611
11th to 20thNight
8%32441435%8%58%
1600
21st to endNight
7%32432345%8%59%
1898
September1st to 10thNight
10%32342445%8%55%
1800
11th to 20thNight
11%324424447%56%
1952
21st to endNight
9%424323446%59%
1980
October1st to 10thNight
14%6%2432345%6%52%
2155
11th to 20thNight
14%7%23233335%55%
2160
21st to endNight
16%6%24333345%51%
2376
November1st to 10thNight
8%32433435%7%58%
2272
11th to 20thNight
10%6%25%5%3345%7%50%
2611
21st to endNight
14%7%4442335%6%49%
2660
December1st to 10thNight
10%8%35%5%35%45%6%45%
2660
11th to 20thNight
12%8%47%5%33346%46%
3279
21st to endNight
19%15%7%11%5%2333426%
4884

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
56%6%13%15%8%1
2819
11th to 20thDay
54%5%13%19%9%
2850
21st to endDay
62%5%11%14%7%
3135
February1st to 10thDay
50%6%12%19%10%2
1710
11th to 20thDay
44%6%13%22%12%2
1619
21st to endDay
45%5%13%23%13%2
1485
March1st to 10thDay
46%411%24%12%2
1980
11th to 20thDay
49%6%9%22%12%2
1980
21st to endDay
57%6%12%17%7%1
2178
April1st to 10thDay
43%6%11%26%13%2
2087
11th to 20thDay
46%5%12%22%14%1
2134
21st to endDay
47%6%10%25%11%1
2330
May1st to 10thDay
48%7%13%19%12%1
2340
11th to 20thDay
44%7%13%23%12%
2306
21st to endDay
46%8%14%20%11%2
2691
June1st to 10thDay
32%9%15%28%14%2
2520
11th to 20thDay
32%8%14%27%18%2
2520
21st to endDay
33%8%15%27%14%3
2520
July1st to 10thDay
30%7%16%31%12%4
2398
11th to 20thDay
29%8%13%27%18%4
2271
21st to endDay
27%7%17%32%15%2
2405
August1st to 10thDay
34%9%18%25%12%2
2314
11th to 20thDay
31%8%14%28%18%1
2301
21st to endDay
32%6%10%28%18%6%
2458
September1st to 10thDay
32%6%11%28%19%5%
2160
11th to 20thDay
31%6%12%29%21%2
2004
21st to endDay
29%5%9%31%23%2
1967
October1st to 10thDay
37%411%26%20%2
1800
11th to 20thDay
34%48%26%23%5%
1800
21st to endDay
38%5%11%24%16%5%
1980
November1st to 10thDay
31%415%27%20%3
1803
11th to 20thDay
38%312%27%17%2
1568
21st to endDay
42%5%12%26%15%1
1520
December1st to 10thDay
39%7%15%25%12%1
1520
11th to 20thDay
46%5%17%26%5%1
1915
21st to endDay
64%5%10%15%6%1
2783
January1st to 10thNight
53%6%11%19%10%1
4135
11th to 20thNight
47%5%12%24%11%1
4120
21st to endNight
57%5%14%15%8%1
4532
February1st to 10thNight
47%5%12%19%14%3
2470
11th to 20thNight
41%5%12%23%16%2
2333
21st to endNight
41%412%21%17%5%
1786
March1st to 10thNight
37%5%11%28%17%2
1980
11th to 20thNight
43%6%10%24%16%2
1980
21st to endNight
55%6%11%18%8%2
2178
April1st to 10thNight
34%7%12%27%17%3
1872
11th to 20thNight
39%7%9%27%15%2
1775
21st to endNight
42%6%9%24%16%2
1626
May1st to 10thNight
42%9%11%23%13%2
1620
11th to 20thNight
37%7%13%25%16%1
1594
21st to endNight
38%7%16%25%11%3
1584
June1st to 10thNight
22%9%18%31%16%3
1440
11th to 20thNight
23%9%17%28%20%4
1440
21st to endNight
21%8%19%30%18%4
1440
July1st to 10thNight
24%7%16%31%17%4
1449
11th to 20thNight
21%7%16%32%19%4
1566
21st to endNight
23%7%13%36%19%2
1673
August1st to 10thNight
25%7%20%31%15%1
1601
11th to 20thNight
26%6%14%34%18%3
1600
21st to endNight
23%6%13%26%22%9%
1898
September1st to 10thNight
28%6%11%26%22%7%
1800
11th to 20thNight
28%5%10%32%22%3
1952
21st to endNight
27%5%8%32%26%3
1980
October1st to 10thNight
33%410%26%23%4
2155
11th to 20thNight
33%49%24%23%7%
2160
21st to endNight
36%5%10%23%23%3
2376
November1st to 10thNight
25%5%15%26%24%5%
2272
11th to 20thNight
33%410%30%19%3
2611
21st to endNight
37%5%10%28%18%2
2660
December1st to 10thNight
40%5%13%28%13%1
2660
11th to 20thNight
42%412%31%10%1
3281
21st to endNight
63%48%17%8%1
4884

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
21%13%35%23%8%
270
11th to 20thDay
21%19%35%21%5%
270
21st to endDay
16%10%43%26%4
297
February1st to 10thDay
16%18%43%20%31
270
11th to 20thDay
14%19%40%21%5%
252
21st to endDay
17%20%43%18%2
198
March1st to 10thDay
19%15%42%21%21
240
11th to 20thDay
31%10%32%23%31
240
21st to endDay
35%20%27%14%5%
264
April1st to 10thDay
24%13%36%20%6%1
347
11th to 20thDay
18%15%35%24%7%
412
21st to endDay
24%16%33%18%8%1
590
May1st to 10thDay
18%14%32%26%8%1
603
11th to 20thDay
19%11%32%24%12%2
625
21st to endDay
19%9%26%27%17%3
679
June1st to 10thDay
8%422%33%25%8%
630
11th to 20thDay
7%5%27%37%20%4
630
21st to endDay
8%6%35%32%15%3
630
July1st to 10thDay
9%216%32%29%11%
621
11th to 20thDay
7%321%37%24%7%
618
21st to endDay
6%214%44%28%5%
684
August1st to 10thDay
9%218%41%25%6%
626
11th to 20thDay
9%319%36%27%6%
615
21st to endDay
8%319%33%30%8%
577
September1st to 10thDay
14%422%30%24%5%
450
11th to 20thDay
9%420%38%21%8%
294
21st to endDay
14%7%30%29%17%3
270
October1st to 10thDay
19%9%27%27%12%6%
270
11th to 20thDay
13%21%40%19%6%1
270
21st to endDay
17%18%32%24%7%2
297
November1st to 10thDay
13%12%40%25%8%2
270
11th to 20thDay
18%14%39%21%7%1
270
21st to endDay
23%11%36%22%8%
270
December1st to 10thDay
8%18%39%27%6%2
270
11th to 20thDay
18%15%34%25%7%1
270
21st to endDay
22%19%40%17%2
297
January1st to 10thNight
11%13%39%29%7%
950
11th to 20thNight
15%14%38%26%6%
950
21st to endNight
14%12%41%28%5%
1045
February1st to 10thNight
17%11%42%26%4
950
11th to 20thNight
16%11%40%27%5%
902
21st to endNight
16%16%42%19%6%1
602
March1st to 10thNight
15%14%40%26%6%
540
11th to 20thNight
21%8%35%29%6%
540
21st to endNight
27%12%36%19%6%
594
April1st to 10thNight
14%13%41%27%5%
540
11th to 20thNight
17%12%38%26%6%
533
21st to endNight
20%11%35%28%6%1
540
May1st to 10thNight
15%10%35%33%6%1
540
11th to 20thNight
17%9%32%30%11%1
531
21st to endNight
13%7%30%35%14%1
584
June1st to 10thNight
5%424%45%21%1
540
11th to 20thNight
8%326%45%18%
540
21st to endNight
5%332%44%15%1
540
July1st to 10thNight
7%215%42%31%3
525
11th to 20thNight
5%116%47%29%2
522
21st to endNight
4216%48%28%1
591
August1st to 10thNight
5%121%47%25%1
537
11th to 20thNight
9%213%48%26%2
534
21st to endNight
9%216%42%29%3
594
September1st to 10thNight
11%221%39%23%2
540
11th to 20thNight
13%321%40%23%1
540
21st to endNight
10%429%41%15%1
540
October1st to 10thNight
16%6%29%33%14%2
715
11th to 20thNight
18%8%39%28%8%
720
21st to endNight
19%10%36%28%7%
792
November1st to 10thNight
9%11%35%36%9%
792
11th to 20thNight
13%14%39%28%6%
950
21st to endNight
18%10%35%28%8%
950
December1st to 10thNight
15%12%38%28%6%1
950
11th to 20thNight
19%9%36%30%7%
950
21st to endNight
20%14%38%24%4
1045
Page generated at 2024-02-12 05:35:33. Version ac07

Copyright 2024 Attilla Danko


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