Mingan
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mingan 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
30%
23005
13%
74770
6%
22952
37%
22952
16%
52793

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
25%
850
15%
2838
6%
847
34%
847
15%
2038
January11th to 20thNight
23%
829
15%
2787
5%
829
34%
829
13%
2012
January21st to endNight
24%
860
17%
2866
8%
860
36%
860
17%
1970
February1st to 10thNight
27%
720
16%
2340
7%
720
37%
720
17%
1610
February11th to 20thNight
27%
703
14%
2276
8%
700
35%
700
15%
1629
February21st to endNight
30%
592
15%
1924
7%
592
41%
592
17%
1339
March1st to 10thNight
28%
719
18%
2084
9%
719
38%
719
20%
1450
March11th to 20thNight
30%
720
18%
1980
8%
720
38%
720
20%
1423
March21st to endNight
25%
769
17%
2155
5%
769
35%
769
17%
1582
April1st to 10thNight
24%
540
12%
1800
7%
540
30%
540
13%
1341
April11th to 20thNight
29%
534
17%
1601
10%
534
36%
534
20%
1105
April21st to endNight
30%
540
14%
1584
8%
540
37%
540
20%
1131
May1st to 10thNight
36%
540
11%
1440
7%
540
40%
540
21%
1057
May11th to 20thNight
38%
532
11%
1417
5%
532
41%
532
23%
1019
May21st to endNight
34%
405
8%
1374
5%
405
38%
405
18%
955
June1st to 10thNight
38%
360
5%
1260
4%
360
42%
360
16%
892
June11th to 20thNight
42%
360
3%
1260
1%
360
44%
360
17%
861
June21st to endNight
42%
360
2%
1260
1%
360
42%
360
14%
932
July1st to 10thNight
44%
350
4%
1225
3%
350
47%
350
18%
835
July11th to 20thNight
47%
348
7%
1218
7%
348
49%
348
21%
783
July21st to endNight
45%
424
9%
1329
7%
401
47%
401
17%
924
August1st to 10thNight
50%
538
8%
1447
6%
534
51%
534
23%
1027
August11th to 20thNight
46%
532
9%
1596
7%
532
49%
532
21%
1120
August21st to endNight
43%
594
14%
1802
9%
594
46%
594
20%
1243
September1st to 10thNight
37%
540
15%
1800
10%
540
44%
540
22%
1168
September11th to 20thNight
36%
583
14%
1843
9%
583
43%
583
20%
1249
September21st to endNight
34%
720
17%
2048
10%
720
41%
720
22%
1418
October1st to 10thNight
29%
720
18%
2160
8%
720
38%
720
19%
1518
October11th to 20thNight
30%
720
15%
2160
7%
720
35%
720
16%
1603
October21st to endNight
27%
847
13%
2586
6%
847
34%
847
17%
1887
November1st to 10thNight
19%
830
14%
2593
4%
830
29%
830
15%
1876
November11th to 20thNight
23%
850
11%
2660
5%
850
30%
850
13%
1993
November21st to endNight
22%
850
13%
2660
5%
850
30%
850
12%
2031
December1st to 10thNight
19%
850
13%
2818
4%
850
30%
850
12%
2069
December11th to 20thNight
17%
850
14%
3473
4%
849
28%
849
11%
2539
December21st to endNight
23%
926
10%
5106
6%
907
32%
907
10%
3164

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%9%46%5%3445%6%33%
74704
Night
19%11%47%5%3445%6%32%
75109
TransparencyDay
53%312%21%10%1
74389
Night
55%311%20%11%1
74959
SeeingDay
27%7%26%25%12%3
15472
Night
26%7%25%29%11%1
23016

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
13%17%7%9%5%3445%6%28%
1327
11th to 20thDay
15%16%6%9%6%34446%28%
1295
21st to endDay
13%12%47%7%345%7%8%30%
1487
February1st to 10thDay
10%12%5%9%6%46%5%5%5%33%
1620
11th to 20thDay
10%15%5%9%6%4445%6%31%
1573
21st to endDay
9%13%5%8%7%45%5%46%36%
1332
March1st to 10thDay
11%13%5%7%7%345%46%35%
1868
11th to 20thDay
16%13%45%5%4445%5%34%
1980
21st to endDay
13%15%5%7%5%35%45%5%34%
2200
April1st to 10thDay
23%13%47%5%35%346%27%
2160
11th to 20thDay
16%10%36%5%34446%38%
2307
21st to endDay
25%8%34434436%36%
2376
May1st to 10thDay
25%9%26%7%34446%30%
2520
11th to 20thDay
21%8%46%4345%5%7%34%
2478
21st to endDay
25%7%26%5%35%5%5%7%32%
2917
June1st to 10thDay
25%8%36%5%3445%6%31%
2700
11th to 20thDay
22%6%35%435%5%5%8%34%
2700
21st to endDay
26%6%36%5%3445%8%30%
2700
July1st to 10thDay
17%7%36%7%45%6%7%8%31%
2700
11th to 20thDay
18%5%25%5%346%7%8%37%
2700
21st to endDay
22%7%36%5%3446%7%31%
2892
August1st to 10thDay
14%7%36%6%45%6%7%8%34%
2478
11th to 20thDay
22%8%35%5%2445%7%34%
2304
21st to endDay
20%5%35%6%25%6%6%8%35%
2553
September1st to 10thDay
21%5%26%5%345%5%6%37%
2160
11th to 20thDay
25%8%34423345%38%
2116
21st to endDay
21%7%35%5%245%46%39%
1911
October1st to 10thDay
19%6%36%5%3445%6%39%
1800
11th to 20thDay
25%8%345%3445%7%32%
1800
21st to endDay
25%10%35%5%43345%32%
1767
November1st to 10thDay
23%8%46%6%3445%6%31%
1485
11th to 20thDay
22%13%47%5%24436%29%
1520
21st to endDay
22%13%5%8%5%34446%27%
1520
December1st to 10thDay
16%16%5%8%5%445%46%27%
1359
11th to 20thDay
21%11%6%7%6%35%5%5%5%25%
1668
21st to endDay
12%13%48%6%35%446%35%
2431
January1st to 10thNight
15%15%5%10%6%3435%6%28%
2838
11th to 20thNight
17%14%6%8%6%34447%28%
2787
21st to endNight
10%14%6%9%7%4445%7%31%
2866
February1st to 10thNight
9%14%6%9%6%445%5%6%33%
2340
11th to 20thNight
13%15%5%7%7%35%45%5%31%
2273
21st to endNight
10%13%5%9%7%45%5%45%33%
1924
March1st to 10thNight
13%13%5%8%6%34445%36%
2075
11th to 20thNight
14%13%5%7%5%445%5%5%33%
1979
21st to endNight
14%15%5%8%6%34345%32%
2155
April1st to 10thNight
23%12%5%7%6%345%5%6%25%
1800
11th to 20thNight
19%10%46%5%3435%5%36%
1601
21st to endNight
26%9%35%6%2444433%
1584
May1st to 10thNight
25%8%35%5%245%5%6%31%
1440
11th to 20thNight
21%7%47%434447%35%
1416
21st to endNight
24%8%35%5%35%446%34%
1373
June1st to 10thNight
28%6%35%5%435%5%5%31%
1260
11th to 20thNight
24%7%26%6%3445%8%32%
1260
21st to endNight
26%7%37%6%46%45%6%26%
1260
July1st to 10thNight
17%8%47%5%36%5%6%7%33%
1260
11th to 20thNight
19%8%35%5%25%46%8%37%
1260
21st to endNight
21%7%37%5%346%7%8%29%
1407
August1st to 10thNight
19%8%25%5%35%5%6%9%33%
1458
11th to 20thNight
22%6%36%5%35%5%46%34%
1596
21st to endNight
18%8%37%6%35%5%6%7%32%
1802
September1st to 10thNight
23%7%244235%5%6%39%
1800
11th to 20thNight
24%5%26%43445%6%37%
1843
21st to endNight
23%6%35%42435%6%38%
2048
October1st to 10thNight
23%8%37%5%2336%5%35%
2160
11th to 20thNight
30%8%36%5%25%45%5%29%
2160
21st to endNight
25%9%36%5%34445%32%
2586
November1st to 10thNight
24%10%36%5%34446%30%
2593
11th to 20thNight
24%13%47%6%34445%26%
2660
21st to endNight
23%16%46%5%33435%26%
2660
December1st to 10thNight
20%14%5%7%5%345%45%27%
2818
11th to 20thNight
22%12%6%7%5%34445%28%
3531
21st to endNight
13%14%47%43446%7%34%
5236

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
57%211%17%11%2
1328
11th to 20thDay
60%29%18%9%2
1295
21st to endDay
52%28%23%13%2
1487
February1st to 10thDay
53%210%20%13%2
1620
11th to 20thDay
56%210%19%12%1
1581
21st to endDay
52%28%22%15%1
1332
March1st to 10thDay
52%29%22%12%2
1872
11th to 20thDay
55%36%19%14%3
1980
21st to endDay
54%28%19%12%4
2200
April1st to 10thDay
62%27%14%12%3
2160
11th to 20thDay
49%310%23%13%3
2307
21st to endDay
54%211%19%13%1
2376
May1st to 10thDay
57%29%22%8%1
2520
11th to 20thDay
52%312%20%11%1
2482
21st to endDay
55%311%20%10%1
2917
June1st to 10thDay
58%311%18%10%1
2700
11th to 20thDay
51%412%22%10%1
2700
21st to endDay
54%313%21%9%
2700
July1st to 10thDay
50%418%20%8%
2625
11th to 20thDay
44%417%27%8%
2619
21st to endDay
52%5%15%22%6%
2730
August1st to 10thDay
46%6%26%18%5%
2464
11th to 20thDay
51%318%22%6%
2304
21st to endDay
49%419%23%5%
2553
September1st to 10thDay
47%414%26%9%
2160
11th to 20thDay
51%415%22%9%
2116
21st to endDay
49%412%24%11%
1911
October1st to 10thDay
47%318%23%9%1
1800
11th to 20thDay
54%313%24%8%
1800
21st to endDay
58%310%18%10%1
1767
November1st to 10thDay
55%412%18%11%1
1485
11th to 20thDay
59%312%19%7%
1520
21st to endDay
62%39%17%9%
1520
December1st to 10thDay
59%310%20%6%1
1359
11th to 20thDay
62%29%19%8%1
1668
21st to endDay
52%111%20%13%4
2431
January1st to 10thNight
57%310%19%10%
2838
11th to 20thNight
58%39%19%10%2
2787
21st to endNight
54%26%23%14%1
2866
February1st to 10thNight
53%29%20%13%4
2340
11th to 20thNight
56%39%17%13%1
2276
21st to endNight
54%28%19%14%3
1924
March1st to 10thNight
52%27%21%16%2
2084
11th to 20thNight
53%38%18%16%2
1980
21st to endNight
55%46%19%11%5%
2155
April1st to 10thNight
62%26%14%13%3
1800
11th to 20thNight
52%29%20%14%3
1601
21st to endNight
55%110%16%17%1
1584
May1st to 10thNight
55%310%21%10%1
1440
11th to 20thNight
52%211%23%11%1
1417
21st to endNight
53%311%18%14%1
1374
June1st to 10thNight
56%211%20%9%1
1260
11th to 20thNight
53%313%21%9%1
1260
21st to endNight
59%411%17%7%1
1260
July1st to 10thNight
50%5%18%21%6%
1225
11th to 20thNight
47%413%27%9%1
1218
21st to endNight
52%5%16%21%6%
1329
August1st to 10thNight
49%5%22%19%5%
1447
11th to 20thNight
51%419%20%6%
1596
21st to endNight
50%416%24%5%
1802
September1st to 10thNight
47%314%25%11%1
1800
11th to 20thNight
50%314%25%8%
1843
21st to endNight
49%311%24%12%1
2048
October1st to 10thNight
52%310%23%10%2
2160
11th to 20thNight
58%211%21%8%
2160
21st to endNight
57%210%20%8%2
2586
November1st to 10thNight
56%312%17%11%2
2593
11th to 20thNight
61%213%16%7%
2660
21st to endNight
63%211%15%9%
2660
December1st to 10thNight
60%310%18%9%
2818
11th to 20thNight
60%26%21%10%1
3532
21st to endNight
51%213%20%12%2
5236

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
22%8%33%23%12%3
180
11th to 20thDay
29%9%25%24%12%2
170
21st to endDay
20%10%27%28%12%3
234
February1st to 10thDay
19%7%39%26%8%1
340
11th to 20thDay
18%10%30%29%11%2
336
21st to endDay
18%8%30%28%11%4
280
March1st to 10thDay
19%9%31%29%9%3
388
11th to 20thDay
24%7%28%26%10%4
420
21st to endDay
25%12%28%23%11%2
462
April1st to 10thDay
31%11%28%23%5%1
420
11th to 20thDay
24%7%30%26%10%3
412
21st to endDay
30%6%25%23%12%4
456
May1st to 10thDay
31%5%24%25%11%4
603
11th to 20thDay
26%7%28%24%10%4
624
21st to endDay
29%9%29%23%8%1
680
June1st to 10thDay
31%7%25%26%10%1
630
11th to 20thDay
30%423%26%14%4
630
21st to endDay
30%5%23%24%13%4
630
July1st to 10thDay
24%424%30%15%4
620
11th to 20thDay
24%421%33%16%3
618
21st to endDay
30%418%27%18%4
685
August1st to 10thDay
22%319%32%19%5%
597
11th to 20thDay
24%6%19%31%17%4
439
21st to endDay
23%5%27%27%13%5%
495
September1st to 10thDay
26%8%24%27%12%3
450
11th to 20thDay
31%9%23%23%11%2
450
21st to endDay
28%7%34%18%10%2
415
October1st to 10thDay
24%8%34%22%9%4
360
11th to 20thDay
33%9%26%18%11%4
360
21st to endDay
34%10%21%21%11%4
396
November1st to 10thDay
30%12%27%24%6%1
365
11th to 20thDay
34%8%25%24%6%2
370
21st to endDay
30%11%28%23%7%1
370
December1st to 10thDay
23%11%23%26%12%5%
209
11th to 20thDay
23%17%29%22%7%2
180
21st to endDay
23%10%37%23%8%
198
January1st to 10thNight
23%6%31%30%9%1
850
11th to 20thNight
25%11%27%27%8%1
829
21st to endNight
19%10%35%27%9%1
860
February1st to 10thNight
16%12%35%28%9%1
720
11th to 20thNight
21%9%31%30%8%1
703
21st to endNight
17%9%30%26%16%3
592
March1st to 10thNight
18%10%32%28%11%1
720
11th to 20thNight
21%8%32%28%10%1
720
21st to endNight
21%13%27%28%9%2
769
April1st to 10thNight
29%8%26%27%10%
540
11th to 20thNight
24%6%30%28%11%1
534
21st to endNight
29%5%24%30%10%2
540
May1st to 10thNight
29%220%32%15%2
540
11th to 20thNight
23%425%31%16%2
532
21st to endNight
26%5%23%32%13%1
406
June1st to 10thNight
31%418%37%9%1
360
11th to 20thNight
28%315%32%21%1
360
21st to endNight
32%215%34%18%1
360
July1st to 10thNight
23%416%37%18%2
350
11th to 20thNight
23%213%45%16%1
348
21st to endNight
27%112%35%22%3
424
August1st to 10thNight
24%112%37%23%3
538
11th to 20thNight
24%315%35%23%1
532
21st to endNight
22%318%36%19%2
594
September1st to 10thNight
27%424%30%13%2
540
11th to 20thNight
28%5%22%32%11%2
583
21st to endNight
27%7%24%32%10%
720
October1st to 10thNight
30%6%27%28%8%1
720
11th to 20thNight
36%5%20%26%12%1
720
21st to endNight
31%8%23%29%9%1
847
November1st to 10thNight
33%10%30%21%6%1
830
11th to 20thNight
34%9%23%26%7%2
850
21st to endNight
33%9%25%27%5%1
850
December1st to 10thNight
29%10%28%24%7%1
850
11th to 20thNight
26%13%34%20%6%1
850
21st to endNight
26%12%29%25%7%1
935
Page generated at 2024-01-13 09:37:56. Version ac07

Copyright 2024 Attilla Danko


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