Bass Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bass Lake clear sky chart from 2005-11-06 to 2024-03-06.

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
32%
24929
11%
80922
8%
24828
36%
24828
14%
61641

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
11%
946
3%
4415
1%
926
14%
926
3%
3888
January11th to 20thNight
11%
948
2%
4440
1%
930
13%
930
2%
4171
January21st to endNight
10%
1037
1%
4880
1%
1023
11%
1023
2%
4520
February1st to 10thNight
15%
869
7%
2499
3%
869
19%
869
7%
2141
February11th to 20thNight
16%
740
8%
2219
3%
740
21%
740
7%
1877
February21st to endNight
16%
628
7%
1884
2%
628
22%
628
10%
1525
March1st to 10thNight
29%
743
13%
2227
7%
743
34%
743
17%
1608
March11th to 20thNight
30%
720
19%
2070
9%
720
37%
720
20%
1451
March21st to endNight
34%
679
16%
2065
12%
679
40%
679
18%
1460
April1st to 10thNight
27%
540
13%
1800
8%
540
35%
540
16%
1262
April11th to 20thNight
34%
533
18%
1740
14%
533
41%
533
19%
1186
April21st to endNight
37%
540
17%
1620
10%
540
43%
540
21%
1098
May1st to 10thNight
37%
540
14%
1620
9%
540
42%
540
21%
1117
May11th to 20thNight
45%
531
18%
1499
12%
531
52%
531
25%
1039
May21st to endNight
50%
583
15%
1552
10%
582
55%
582
32%
1007
June1st to 10thNight
53%
540
15%
1440
10%
540
56%
540
31%
935
June11th to 20thNight
53%
540
16%
1440
10%
540
56%
540
32%
914
June21st to endNight
60%
540
16%
1440
10%
540
63%
540
33%
903
July1st to 10thNight
69%
525
16%
1400
12%
525
70%
525
42%
818
July11th to 20thNight
61%
522
19%
1392
13%
522
64%
522
40%
837
July21st to endNight
60%
591
18%
1487
13%
558
63%
558
36%
930
August1st to 10thNight
64%
537
21%
1498
17%
534
65%
534
36%
898
August11th to 20thNight
65%
534
23%
1598
20%
534
70%
534
38%
912
August21st to endNight
58%
594
21%
1970
19%
594
63%
594
29%
1149
September1st to 10thNight
54%
540
19%
1800
18%
540
57%
540
27%
1080
September11th to 20thNight
58%
693
26%
1953
20%
693
63%
693
36%
1194
September21st to endNight
48%
720
18%
1980
14%
720
50%
720
26%
1343
October1st to 10thNight
43%
720
20%
1980
15%
720
47%
720
26%
1340
October11th to 20thNight
26%
720
11%
2240
5%
720
34%
720
14%
1681
October21st to endNight
21%
792
10%
2574
7%
792
26%
792
11%
2012
November1st to 10thNight
25%
740
15%
2406
10%
740
33%
740
14%
1731
November11th to 20thNight
16%
760
9%
2470
5%
760
21%
760
8%
2030
November21st to endNight
16%
807
7%
2517
3%
807
20%
807
8%
2067
December1st to 10thNight
10%
950
3%
2660
1%
950
12%
950
5%
2370
December11th to 20thNight
12%
950
4%
3281
2%
949
14%
949
4%
2915
December21st to endNight
8%
1037
3%
4866
1%
1026
11%
1026
3%
4232

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%11%5%8%6%3445%6%34%
78438
Night
16%13%6%9%7%34445%29%
81137
TransparencyDay
51%7%12%19%10%1
78139
Night
57%7%10%16%8%1
80957
SeeingDay
18%13%28%26%12%3
14882
Night
21%12%27%27%12%2
24955

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
13%28%14%15%8%332228%
2527
11th to 20thDay
13%17%10%16%16%9%5%3335%
2530
21st to endDay
18%21%11%14%9%45%3349%
2783
February1st to 10thDay
10%15%8%13%15%5%5%34416%
1678
11th to 20thDay
14%14%8%16%12%5%5%33417%
1848
21st to endDay
13%14%7%12%9%36%45%6%22%
1570
March1st to 10thDay
13%10%6%8%7%45%5%5%5%32%
1850
11th to 20thDay
12%9%5%8%7%35%5%5%7%34%
1890
21st to endDay
17%10%47%6%345%6%7%31%
2308
April1st to 10thDay
18%12%5%5%5%25%5%46%32%
2160
11th to 20thDay
21%9%35%5%345%5%6%35%
2169
21st to endDay
16%9%36%6%35%5%5%6%36%
2340
May1st to 10thDay
14%8%36%5%3446%8%40%
2340
11th to 20thDay
17%6%2442446%8%43%
2393
21st to endDay
11%5%25%5%35%5%6%8%46%
2725
June1st to 10thDay
12%5%25%435%45%8%48%
2520
11th to 20thDay
13%425%43445%9%47%
2520
21st to endDay
11%425%43446%9%47%
2520
July1st to 10thDay
6%41432346%9%57%
2520
11th to 20thDay
9%42442445%8%54%
2520
21st to endDay
9%3244345%6%9%52%
2743
August1st to 10thDay
9%324435%5%6%10%49%
2428
11th to 20thDay
9%425%4345%5%7%52%
2303
21st to endDay
11%5%244345%5%7%50%
2384
September1st to 10thDay
14%5%26%444446%46%
2160
11th to 20thDay
12%5%25%5%3436%7%48%
1988
21st to endDay
15%7%26%5%345%5%8%40%
1980
October1st to 10thDay
16%7%36%5%3445%7%40%
1980
11th to 20thDay
26%12%37%7%345%5%6%22%
1718
21st to endDay
26%14%37%5%3445%6%23%
1782
November1st to 10thDay
16%15%46%6%44446%32%
1672
11th to 20thDay
15%23%8%10%5%4445%5%18%
1710
21st to endDay
21%21%8%10%6%2334417%
1658
December1st to 10thDay
16%22%15%15%6%3423312%
1520
11th to 20thDay
16%22%11%15%9%23345%10%
1918
21st to endDay
20%22%10%12%9%4433310%
2783
January1st to 10thNight
15%25%12%14%9%3322312%
4428
11th to 20thNight
13%19%10%18%13%9%43237%
4440
21st to endNight
17%23%12%15%10%442338%
4884
February1st to 10thNight
12%17%8%14%13%5%443417%
2499
11th to 20thNight
13%12%9%15%11%5%5%445%18%
2218
21st to endNight
15%15%6%12%8%44346%22%
1884
March1st to 10thNight
15%10%5%9%6%34447%34%
2227
11th to 20thNight
12%10%47%6%2445%7%38%
2070
21st to endNight
18%9%46%5%35%45%6%34%
2065
April1st to 10thNight
17%11%46%5%3446%7%33%
1800
11th to 20thNight
21%8%34435%46%6%36%
1740
21st to endNight
18%9%36%5%2445%6%38%
1620
May1st to 10thNight
15%7%26%6%36%5%6%7%35%
1620
11th to 20thNight
15%6%36%6%445%5%7%39%
1498
21st to endNight
13%6%35%5%2445%10%44%
1551
June1st to 10thNight
12%5%25%425%47%8%44%
1440
11th to 20thNight
11%6%25%5%3445%8%46%
1440
21st to endNight
9%5%345%35%5%7%10%46%
1440
July1st to 10thNight
7%3134446%5%10%53%
1440
11th to 20thNight
8%425%5%245%6%9%51%
1440
21st to endNight
8%425%5%35%5%5%7%51%
1575
August1st to 10thNight
8%4245%25%5%7%8%49%
1507
11th to 20thNight
8%324435%5%6%7%54%
1598
21st to endNight
12%4235%3445%6%51%
1970
September1st to 10thNight
12%5%25%5%3445%6%49%
1800
11th to 20thNight
12%5%2442345%6%54%
1953
21st to endNight
17%6%25%5%35%5%5%7%42%
1980
October1st to 10thNight
18%7%25%424347%44%
1980
11th to 20thNight
26%11%36%6%33345%31%
2240
21st to endNight
27%13%27%5%34446%25%
2574
November1st to 10thNight
15%15%47%6%34346%33%
2406
11th to 20thNight
17%21%7%10%5%3444420%
2470
21st to endNight
20%21%8%8%5%3334420%
2517
December1st to 10thNight
17%24%13%11%6%3434413%
2660
11th to 20thNight
16%22%9%13%7%3444413%
3279
21st to endNight
24%23%9%11%6%3334412%
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
85%5%441
2528
11th to 20thDay
89%4431
2530
21st to endDay
82%8%7%31
2783
February1st to 10thDay
73%7%6%12%2
1678
11th to 20thDay
73%5%9%9%5%
1858
21st to endDay
65%7%11%12%4
1570
March1st to 10thDay
54%7%14%17%6%
1850
11th to 20thDay
48%7%15%18%10%2
1890
21st to endDay
52%7%12%19%9%1
2308
April1st to 10thDay
53%6%13%18%10%
2160
11th to 20thDay
50%5%10%19%14%2
2169
21st to endDay
48%6%13%17%14%2
2340
May1st to 10thDay
43%7%12%25%12%1
2340
11th to 20thDay
40%7%13%22%16%2
2397
21st to endDay
35%9%14%26%15%1
2725
June1st to 10thDay
35%8%12%26%17%2
2520
11th to 20thDay
35%7%14%24%19%1
2520
21st to endDay
33%9%17%24%16%1
2520
July1st to 10thDay
25%6%15%33%19%3
2451
11th to 20thDay
29%7%15%30%17%2
2445
21st to endDay
28%8%14%29%17%3
2591
August1st to 10thDay
29%9%18%31%12%1
2413
11th to 20thDay
31%8%18%28%14%2
2303
21st to endDay
33%8%14%26%17%2
2384
September1st to 10thDay
40%6%14%24%14%2
2160
11th to 20thDay
36%7%14%31%11%1
1988
21st to endDay
43%8%13%26%10%
1980
October1st to 10thDay
44%8%10%25%12%
1980
11th to 20thDay
62%7%12%15%4
1718
21st to endDay
63%7%13%12%6%
1782
November1st to 10thDay
53%8%11%19%10%
1672
11th to 20thDay
69%6%11%11%4
1710
21st to endDay
71%6%12%7%3
1658
December1st to 10thDay
80%5%6%8%2
1520
11th to 20thDay
77%7%11%41
1915
21st to endDay
80%6%6%5%2
2783
January1st to 10thNight
78%7%7%7%1
4428
11th to 20thNight
85%6%5%31
4440
21st to endNight
83%7%6%31
4884
February1st to 10thNight
72%6%6%11%4
2499
11th to 20thNight
70%7%7%11%4
2219
21st to endNight
65%6%10%13%5%
1884
March1st to 10thNight
51%7%14%21%7%1
2227
11th to 20thNight
46%8%12%20%12%2
2070
21st to endNight
50%7%10%23%9%1
2065
April1st to 10thNight
50%7%10%20%12%1
1800
11th to 20thNight
49%5%8%20%15%3
1740
21st to endNight
47%5%11%20%13%3
1620
May1st to 10thNight
46%7%13%20%12%2
1620
11th to 20thNight
44%8%10%20%16%3
1499
21st to endNight
37%7%11%27%15%3
1552
June1st to 10thNight
35%9%10%28%16%2
1440
11th to 20thNight
35%8%13%24%19%2
1440
21st to endNight
33%9%15%26%15%3
1440
July1st to 10thNight
26%7%14%28%21%4
1400
11th to 20thNight
27%8%14%29%18%3
1392
21st to endNight
32%8%14%26%17%3
1487
August1st to 10thNight
31%7%16%29%15%2
1498
11th to 20thNight
27%7%16%32%16%1
1598
21st to endNight
33%7%12%26%19%2
1970
September1st to 10thNight
35%8%11%26%19%2
1800
11th to 20thNight
31%7%13%34%13%2
1953
21st to endNight
42%7%13%27%10%1
1980
October1st to 10thNight
42%7%9%27%14%1
1980
11th to 20thNight
57%6%12%18%6%1
2240
21st to endNight
61%7%11%15%6%
2574
November1st to 10thNight
53%7%11%19%9%1
2406
11th to 20thNight
68%6%10%10%5%
2470
21st to endNight
67%6%14%10%21
2517
December1st to 10thNight
77%6%7%8%2
2660
11th to 20thNight
76%7%9%5%2
3281
21st to endNight
77%7%9%6%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
19%22%32%19%7%1
270
11th to 20thDay
23%17%41%16%3
270
21st to endDay
26%18%29%24%3
297
February1st to 10thDay
19%29%31%15%5%2
270
11th to 20thDay
20%29%33%16%1
270
21st to endDay
20%30%39%11%
225
March1st to 10thDay
18%26%40%12%3
255
11th to 20thDay
20%16%31%23%9%1
330
21st to endDay
26%16%31%19%7%1
462
April1st to 10thDay
23%14%37%23%31
420
11th to 20thDay
26%21%25%17%9%1
412
21st to endDay
20%15%30%25%9%2
420
May1st to 10thDay
22%15%34%20%8%2
423
11th to 20thDay
19%10%31%27%12%2
539
21st to endDay
14%7%31%29%15%4
679
June1st to 10thDay
12%6%33%32%14%3
630
11th to 20thDay
17%6%28%33%13%3
630
21st to endDay
14%7%28%35%13%4
630
July1st to 10thDay
6%5%24%38%22%5%
621
11th to 20thDay
9%7%25%37%17%5%
618
21st to endDay
8%427%39%17%5%
684
August1st to 10thDay
9%423%33%24%6%
547
11th to 20thDay
13%316%31%25%11%
439
21st to endDay
15%7%21%31%21%5%
495
September1st to 10thDay
16%7%22%31%18%6%
450
11th to 20thDay
12%7%21%32%22%6%
450
21st to endDay
16%13%23%24%17%7%
450
October1st to 10thDay
19%14%26%21%17%4
450
11th to 20thDay
31%14%30%21%4
302
21st to endDay
36%14%31%14%41
297
November1st to 10thDay
23%20%30%19%8%1
270
11th to 20thDay
20%30%33%13%4
270
21st to endDay
29%23%33%14%1
270
December1st to 10thDay
25%27%28%17%3
270
11th to 20thDay
28%26%30%11%41
270
21st to endDay
29%29%28%11%3
297
January1st to 10thNight
23%19%33%19%6%1
950
11th to 20thNight
26%18%32%18%5%1
950
21st to endNight
21%14%36%22%6%
1045
February1st to 10thNight
20%17%34%24%41
869
11th to 20thNight
21%18%32%23%6%
743
21st to endNight
23%17%35%21%3
628
March1st to 10thNight
18%13%32%26%9%1
743
11th to 20thNight
17%14%33%27%8%1
720
21st to endNight
22%10%26%32%9%1
679
April1st to 10thNight
21%14%31%27%6%1
540
11th to 20thNight
24%11%27%28%9%1
533
21st to endNight
21%7%29%30%12%1
540
May1st to 10thNight
18%6%30%34%11%1
540
11th to 20thNight
17%5%24%35%17%1
531
21st to endNight
15%422%37%19%3
584
June1st to 10thNight
13%5%21%41%17%2
540
11th to 20thNight
16%422%36%19%3
540
21st to endNight
11%419%42%22%2
540
July1st to 10thNight
10%115%41%29%5%
525
11th to 20thNight
9%320%35%29%4
522
21st to endNight
9%419%39%27%3
591
August1st to 10thNight
10%216%41%27%4
537
11th to 20thNight
10%216%35%30%7%
534
21st to endNight
13%418%38%24%3
594
September1st to 10thNight
13%5%21%36%19%6%
540
11th to 20thNight
13%7%18%35%22%5%
693
21st to endNight
18%9%21%27%22%3
720
October1st to 10thNight
21%10%22%28%17%2
720
11th to 20thNight
31%12%25%23%7%1
720
21st to endNight
32%14%27%20%6%
792
November1st to 10thNight
23%15%30%23%7%1
740
11th to 20thNight
27%21%28%19%5%
760
21st to endNight
31%16%29%20%4
807
December1st to 10thNight
29%22%30%16%3
950
11th to 20thNight
28%20%31%17%41
950
21st to endNight
32%17%31%18%2
1045
Page generated at 2024-03-03 06:28:59. Version ac07

Copyright © 2024 Attilla Danko.


Bass Lake Clear Sky Chart |Charts Home