Dry Sandy Crossing
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Dry Sandy Crossing 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
50%
24880
22%
80334
16%
24802
57%
24802
33%
46717

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
44%
934
15%
4344
11%
926
50%
926
17%
2857
January11th to 20thNight
44%
767
20%
4086
15%
750
53%
750
16%
2425
January21st to endNight
43%
824
11%
4508
14%
814
51%
814
12%
3333
February1st to 10thNight
36%
760
16%
2470
12%
760
43%
760
24%
1590
February11th to 20thNight
41%
742
17%
2403
12%
740
50%
740
28%
1461
February21st to endNight
34%
628
17%
1961
9%
628
44%
628
26%
1241
March1st to 10thNight
43%
742
19%
2040
10%
742
51%
742
33%
1278
March11th to 20thNight
51%
720
21%
1980
12%
720
57%
720
37%
1168
March21st to endNight
45%
792
19%
2178
12%
792
50%
792
31%
1394
April1st to 10thNight
40%
569
19%
1829
12%
569
49%
569
31%
1075
April11th to 20thNight
39%
533
20%
1777
14%
533
47%
533
28%
1040
April21st to endNight
46%
540
24%
1620
16%
540
53%
540
32%
944
May1st to 10thNight
42%
540
20%
1620
14%
540
46%
540
32%
949
May11th to 20thNight
50%
531
22%
1472
15%
531
54%
531
37%
854
May21st to endNight
52%
584
18%
1552
12%
582
57%
582
36%
929
June1st to 10thNight
59%
540
21%
1440
15%
540
65%
540
48%
772
June11th to 20thNight
48%
540
24%
1440
14%
540
57%
540
49%
765
June21st to endNight
62%
540
29%
1440
22%
540
68%
540
57%
724
July1st to 10thNight
67%
525
23%
1400
19%
525
71%
525
52%
741
July11th to 20thNight
70%
522
29%
1424
24%
522
74%
522
57%
708
July21st to endNight
76%
591
29%
1674
25%
558
78%
558
53%
802
August1st to 10thNight
73%
537
30%
1602
25%
534
75%
534
48%
794
August11th to 20thNight
75%
534
37%
1602
28%
534
81%
534
61%
717
August21st to endNight
73%
594
36%
1898
33%
594
78%
594
52%
878
September1st to 10thNight
67%
540
36%
1800
33%
540
77%
540
54%
791
September11th to 20thNight
68%
631
35%
1891
29%
631
75%
631
54%
901
September21st to endNight
63%
720
34%
2009
23%
720
70%
720
53%
1010
October1st to 10thNight
48%
720
27%
2160
18%
720
55%
720
41%
1179
October11th to 20thNight
54%
720
30%
2160
18%
720
64%
720
43%
1120
October21st to endNight
51%
792
27%
2376
17%
792
59%
792
40%
1286
November1st to 10thNight
44%
801
27%
2357
16%
801
54%
801
38%
1343
November11th to 20thNight
42%
950
22%
2660
12%
950
49%
950
38%
1530
November21st to endNight
46%
950
22%
2660
13%
950
53%
950
38%
1544
December1st to 10thNight
38%
950
15%
2660
7%
950
45%
950
30%
1693
December11th to 20thNight
39%
948
19%
3131
10%
948
45%
948
26%
1876
December21st to endNight
35%
1029
9%
4710
5%
1026
43%
1026
14%
3005

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
35%25%6%45%5%6%9%49%
78622
Night
35%36%6%45%5%6%9%48%
80964
TransparencyDay
32%5%14%25%18%7%
78337
Night
33%5%15%25%17%6%
80771
SeeingDay
6%8%27%32%20%6%
14635
Night
6%6%30%40%15%2
24931

By Month

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 10thDay
25%39%9%5%10%10%11%11%26%
2545
11th to 20thDay
26%47%9%5%7%7%7%9%38%
2860
21st to endDay
15%412%17%9%9%6%5%7%25%
3146
February1st to 10thDay
27%48%6%46%7%6%10%39%
1710
11th to 20thDay
26%5%8%6%36%5%7%8%44%
1665
21st to endDay
27%38%6%46%47%10%43%
1491
March1st to 10thDay
27%36%6%46%6%6%10%44%
2036
11th to 20thDay
15%35%6%46%7%8%11%45%
1980
21st to endDay
48%35%7%46%6%7%10%41%
2178
April1st to 10thDay
49%37%5%35%5%6%9%44%
2130
11th to 20thDay
48%35%7%45%6%6%8%44%
2131
21st to endDay
5%8%26%6%35%5%7%9%44%
2337
May1st to 10thDay
7%6%36%6%46%6%7%8%42%
2340
11th to 20thDay
6%5%25%6%36%6%7%9%45%
2422
21st to endDay
6%6%26%6%46%6%8%9%41%
2724
June1st to 10thDay
5%424435%5%6%10%52%
2520
11th to 20thDay
432343445%9%60%
2520
21st to endDay
221243445%7%66%
2520
July1st to 10thDay
3222325%5%6%8%61%
2520
11th to 20thDay
42134345%6%8%62%
2484
21st to endDay
5%2143245%6%9%59%
2545
August1st to 10thDay
32234245%6%10%58%
2328
11th to 20thDay
32133245%6%8%64%
2299
21st to endDay
321332435%9%66%
2458
September1st to 10thDay
321332335%6%67%
2160
11th to 20thDay
33144235%5%6%64%
2066
21st to endDay
5%424323335%66%
1950
October1st to 10thDay
8%5%25%42335%6%58%
1800
11th to 20thDay
6%5%1332346%8%59%
1800
21st to endDay
35%26%43446%8%56%
1980
November1st to 10thDay
46%25%5%36%5%6%6%52%
1697
11th to 20thDay
35%26%6%35%5%7%10%49%
1520
21st to endDay
17%26%5%35%5%7%11%49%
1520
December1st to 10thDay
26%38%7%47%5%7%11%41%
1520
11th to 20thDay
26%47%10%5%7%6%8%9%35%
1926
21st to endDay
28%49%8%6%8%8%9%11%27%
2794
January1st to 10thNight
16%49%8%5%8%9%11%9%29%
4417
11th to 20thNight
15%5%10%8%5%6%6%8%10%36%
4133
21st to endNight
29%414%15%7%7%6%6%7%24%
4521
February1st to 10thNight
27%47%7%47%6%7%9%39%
2470
11th to 20thNight
37%37%5%46%6%7%9%43%
2402
21st to endNight
26%48%7%37%6%6%9%41%
1961
March1st to 10thNight
38%38%5%35%5%5%9%46%
2040
11th to 20thNight
26%46%5%35%5%5%11%49%
1980
21st to endNight
48%38%6%445%6%7%45%
2178
April1st to 10thNight
5%9%345%35%6%49%48%
1829
11th to 20thNight
49%37%5%35%5%6%9%45%
1777
21st to endNight
5%7%25%6%45%46%9%48%
1620
May1st to 10thNight
6%6%25%5%35%5%6%10%47%
1620
11th to 20thNight
5%5%24435%7%6%9%49%
1471
21st to endNight
6%435%5%446%7%8%48%
1552
June1st to 10thNight
442333446%11%57%
1440
11th to 20thNight
33235%25%447%62%
1440
21st to endNight
2213433447%67%
1440
July1st to 10thNight
22244345%6%8%61%
1440
11th to 20thNight
222232445%10%64%
1472
21st to endNight
22244345%6%8%61%
1773
August1st to 10thNight
32135%25%5%6%9%59%
1611
11th to 20thNight
211232435%8%68%
1602
21st to endNight
221342445%9%64%
1898
September1st to 10thNight
4312333446%69%
1800
11th to 20thNight
32123235%5%9%65%
1891
21st to endNight
5%312323435%68%
2009
October1st to 10thNight
7%6%24423446%57%
2160
11th to 20thNight
5%5%24423346%62%
2160
21st to endNight
5%5%2443435%8%56%
2376
November1st to 10thNight
45%25%5%35%46%10%52%
2357
11th to 20thNight
35%35%5%35%46%9%53%
2660
21st to endNight
36%45%5%345%6%9%51%
2660
December1st to 10thNight
37%36%6%5%5%6%7%10%42%
2660
11th to 20thNight
37%46%7%35%7%9%12%39%
3271
21st to endNight
28%48%8%6%9%6%8%10%31%
4873

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
47%8%15%21%9%1
2546
11th to 20thDay
41%6%18%22%11%1
2860
21st to endDay
59%417%13%6%1
3146
February1st to 10thDay
39%8%18%25%10%1
1710
11th to 20thDay
37%7%20%24%9%2
1674
21st to endDay
35%6%17%26%14%2
1491
March1st to 10thDay
34%6%23%27%10%1
2036
11th to 20thDay
31%7%23%28%11%1
1980
21st to endDay
38%6%19%29%8%1
2178
April1st to 10thDay
37%7%19%22%13%2
2130
11th to 20thDay
37%5%16%28%13%
2134
21st to endDay
36%415%32%13%
2337
May1st to 10thDay
38%413%29%14%2
2340
11th to 20thDay
35%416%32%11%2
2426
21st to endDay
38%417%28%12%1
2724
June1st to 10thDay
27%5%15%29%20%4
2520
11th to 20thDay
23%311%21%28%14%
2520
21st to endDay
18%35%23%34%18%
2520
July1st to 10thDay
20%47%23%29%18%
2451
11th to 20thDay
20%35%19%30%23%
2409
21st to endDay
22%35%20%29%20%
2404
August1st to 10thDay
21%48%24%27%16%
2313
11th to 20thDay
18%36%24%34%15%
2299
21st to endDay
18%37%19%36%17%
2458
September1st to 10thDay
18%36%20%33%20%
2160
11th to 20thDay
20%39%27%26%14%
2066
21st to endDay
22%36%30%32%7%
1950
October1st to 10thDay
29%312%31%21%4
1800
11th to 20thDay
24%316%35%17%4
1800
21st to endDay
28%318%31%18%1
1980
November1st to 10thDay
32%5%16%28%17%2
1697
11th to 20thDay
30%6%22%27%14%2
1520
21st to endDay
30%7%19%27%16%2
1520
December1st to 10thDay
37%7%22%21%12%2
1520
11th to 20thDay
42%6%20%26%6%
1924
21st to endDay
49%5%10%17%14%5%
2794
January1st to 10thNight
45%8%14%23%9%1
4417
11th to 20thNight
41%8%20%20%10%1
4133
21st to endNight
59%5%15%14%6%1
4521
February1st to 10thNight
40%8%18%23%10%1
2470
11th to 20thNight
36%7%18%26%12%2
2403
21st to endNight
39%6%17%23%13%2
1961
March1st to 10thNight
36%5%19%30%9%
2040
11th to 20thNight
31%6%20%31%12%1
1980
21st to endNight
38%6%16%31%8%1
2178
April1st to 10thNight
34%5%19%23%15%4
1829
11th to 20thNight
37%416%27%16%
1777
21st to endNight
35%415%34%13%
1620
May1st to 10thNight
33%5%14%29%17%2
1620
11th to 20thNight
30%5%16%35%12%2
1472
21st to endNight
32%5%18%31%14%1
1552
June1st to 10thNight
23%320%29%20%4
1440
11th to 20thNight
22%310%24%26%15%
1440
21st to endNight
19%2419%35%21%
1440
July1st to 10thNight
21%47%23%27%19%
1400
11th to 20thNight
17%36%19%29%26%
1424
21st to endNight
20%38%20%28%21%
1674
August1st to 10thNight
22%47%28%23%17%
1602
11th to 20thNight
16%27%24%33%19%
1602
21st to endNight
18%37%22%30%19%
1898
September1st to 10thNight
17%36%21%30%23%
1800
11th to 20thNight
18%49%27%28%14%
1891
21st to endNight
20%28%30%32%8%
2009
October1st to 10thNight
29%311%30%22%6%
2160
11th to 20thNight
25%313%34%20%5%
2160
21st to endNight
28%417%32%18%2
2376
November1st to 10thNight
29%5%15%29%19%3
2357
11th to 20thNight
29%5%20%32%12%2
2660
21st to endNight
29%5%18%30%15%2
2660
December1st to 10thNight
37%7%22%22%11%2
2660
11th to 20thNight
36%5%20%29%9%
3272
21st to endNight
46%6%10%18%15%4
4873

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
7%7%26%40%12%7%
270
11th to 20thDay
6%5%29%37%18%4
270
21st to endDay
1335%42%14%5%
297
February1st to 10thDay
8%10%42%31%9%
270
11th to 20thDay
47%44%31%10%4
270
21st to endDay
5%12%40%33%9%2
249
March1st to 10thDay
5%11%34%37%11%1
441
11th to 20thDay
47%29%42%15%3
420
21st to endDay
8%7%27%42%15%2
462
April1st to 10thDay
12%10%27%34%15%3
420
11th to 20thDay
9%14%34%28%13%1
412
21st to endDay
12%14%26%24%19%4
420
May1st to 10thDay
11%16%25%26%17%5%
423
11th to 20thDay
10%10%20%31%23%5%
569
21st to endDay
9%9%23%27%21%11%
679
June1st to 10thDay
5%7%23%27%27%10%
630
11th to 20thDay
5%10%32%31%18%3
630
21st to endDay
35%23%37%25%7%
630
July1st to 10thDay
4316%38%32%8%
621
11th to 20thDay
47%18%33%31%7%
582
21st to endDay
5%316%32%30%13%
487
August1st to 10thDay
3320%30%32%11%
447
11th to 20thDay
3422%28%27%16%
437
21st to endDay
3424%26%30%12%
495
September1st to 10thDay
5%7%24%27%25%12%
450
11th to 20thDay
5%11%26%28%20%11%
450
21st to endDay
7%9%27%30%19%9%
420
October1st to 10thDay
11%7%22%28%23%9%
270
11th to 20thDay
9%11%29%31%16%5%
270
21st to endDay
7%14%36%29%12%2
297
November1st to 10thDay
10%10%34%34%10%1
270
11th to 20thDay
6%11%36%37%8%2
270
21st to endDay
5%8%37%34%13%3
270
December1st to 10thDay
46%37%39%12%2
270
11th to 20thDay
5%7%39%37%11%1
270
21st to endDay
8%7%32%33%14%6%
297
January1st to 10thNight
6%6%32%43%11%2
950
11th to 20thNight
48%35%37%14%2
770
21st to endNight
6%5%33%42%13%2
836
February1st to 10thNight
5%5%45%36%8%1
760
11th to 20thNight
6%7%35%40%9%2
744
21st to endNight
5%10%41%34%9%1
628
March1st to 10thNight
7%6%36%38%12%2
742
11th to 20thNight
5%5%29%47%14%1
720
21st to endNight
9%5%31%43%11%1
792
April1st to 10thNight
10%8%35%38%8%1
569
11th to 20thNight
11%9%35%34%10%1
533
21st to endNight
10%8%30%37%14%1
540
May1st to 10thNight
9%11%31%33%14%1
540
11th to 20thNight
8%6%29%35%20%2
531
21st to endNight
8%6%27%38%18%3
584
June1st to 10thNight
7%5%25%38%23%2
540
11th to 20thNight
6%8%34%42%10%
540
21st to endNight
3324%45%23%1
540
July1st to 10thNight
3220%42%32%1
525
11th to 20thNight
1318%52%24%1
522
21st to endNight
3212%52%32%1
591
August1st to 10thNight
4113%51%30%1
537
11th to 20thNight
3116%50%29%1
534
21st to endNight
3316%46%29%4
594
September1st to 10thNight
5%321%46%23%2
540
11th to 20thNight
3321%46%22%5%
631
21st to endNight
6%323%38%23%6%
720
October1st to 10thNight
10%5%31%32%19%3
720
11th to 20thNight
9%7%26%40%16%2
720
21st to endNight
7%7%29%40%14%3
792
November1st to 10thNight
7%6%38%37%12%1
801
11th to 20thNight
5%10%37%39%8%1
950
21st to endNight
6%7%35%39%12%1
950
December1st to 10thNight
7%9%37%37%9%1
950
11th to 20thNight
8%6%35%42%7%1
950
21st to endNight
7%9%36%36%10%2
1045
Page generated at 2024-03-03 04:28:53. Version ac07

Copyright © 2024 Attilla Danko.


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