Lake Superior Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake Superior Provincial Park clear sky chart from 2005-11-05 to 2018-01-12.

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%
16048
9%
48374
6%
16003
33%
16003
14%
37186

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 15thNight
17%
956
3%
2736
2%
951
18%
951
6%
2455
January16th to endNight
21%
960
6%
2688
3%
960
24%
960
6%
2378
February1st to 15thNight
18%
781
6%
2362
3%
778
21%
778
9%
1983
February16th to endNight
24%
631
9%
1898
6%
631
27%
631
11%
1520
March1st to 15thNight
26%
720
15%
2121
7%
720
33%
720
19%
1506
March16th to endNight
35%
744
18%
2088
11%
744
42%
744
23%
1438
April1st to 15thNight
34%
539
13%
1749
9%
539
38%
539
18%
1222
April16th to endNight
34%
540
16%
1620
8%
540
41%
540
24%
1098
May1st to 15thNight
40%
540
11%
1582
9%
540
43%
540
19%
1121
May16th to endNight
46%
426
13%
1362
11%
425
50%
425
22%
891
June1st to 15thNight
46%
360
9%
1260
8%
360
48%
360
20%
815
June16th to endNight
48%
360
7%
1260
7%
360
48%
360
20%
830
July1st to 15thNight
55%
362
11%
1212
10%
362
56%
362
26%
758
July16th to endNight
55%
564
12%
1417
10%
531
55%
531
28%
962
August1st to 15thNight
58%
539
13%
1527
12%
536
60%
536
31%
965
August16th to endNight
50%
573
16%
1721
12%
573
53%
573
26%
1093
September1st to 15thNight
45%
612
11%
1872
9%
612
47%
612
24%
1251
September16th to endNight
43%
717
14%
1980
11%
717
45%
717
23%
1382
October1st to 15thNight
30%
720
13%
2076
8%
720
35%
720
17%
1537
October16th to endNight
19%
768
7%
2496
4%
768
24%
768
8%
2088
November1st to 15thNight
16%
760
9%
2491
6%
760
20%
760
8%
2052
November16th to endNight
16%
861
5%
2811
3%
861
19%
861
6%
2427
December1st to 15thNight
13%
975
2%
2925
2%
975
14%
975
5%
2629
December16th to endNight
15%
1040
4%
3120
2%
1040
17%
1040
5%
2785

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
17%10%46%5%3445%7%30%
48976
Night
16%13%5%8%6%34446%26%
48535
Cloud CoverDay
17%11%46%5%3445%7%30%
48985
Night
16%13%5%8%6%34446%26%
48540
TransparencyDay
53%6%13%18%7%
48654
Night
58%7%11%15%6%
48376
SeeingDay
22%7%26%27%12%3
6361
Night
22%9%28%26%10%1
16048

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 15thDay
15%19%7%12%6%36%5%6%5%11%
1444
16th to endDay
11%16%7%12%9%4445%5%18%
1536
February1st to 15thDay
9%15%6%9%10%6%6%5%46%19%
1497
16th to endDay
8%14%7%12%8%45%45%6%21%
1573
March1st to 15thDay
13%11%49%4345%47%31%
1829
16th to endDay
13%10%46%5%25%347%36%
2145
April1st to 15thDay
19%10%35%42445%8%31%
2199
16th to endDay
17%10%35%5%2445%7%33%
2340
May1st to 15thDay
17%8%36%5%35%446%33%
2367
16th to endDay
17%6%34435%45%7%35%
2753
June1st to 15thDay
18%6%25%435%45%9%32%
2700
16th to endDay
16%6%25%436%46%8%34%
2700
July1st to 15thDay
16%5%2442445%8%39%
2675
16th to endDay
17%5%2432445%8%40%
2655
August1st to 15thDay
13%6%244345%6%8%40%
2423
16th to endDay
20%6%25%433448%37%
2480
September1st to 15thDay
21%6%25%42435%7%36%
2076
16th to endDay
22%6%25%42335%7%35%
1980
October1st to 15thDay
25%11%35%432345%29%
1881
16th to endDay
28%16%5%6%6%3343317%
1728
November1st to 15thDay
21%18%5%7%5%25%445%18%
1696
16th to endDay
20%19%6%7%7%35%5%45%15%
1478
December1st to 15thDay
14%22%9%12%8%3334314%
1365
16th to endDay
16%24%8%10%5%3435%5%11%
1456
January1st to 15thNight
16%18%9%13%7%3446%5%10%
2736
16th to endNight
11%17%8%11%10%45%5%45%15%
2688
February1st to 15thNight
9%16%8%13%10%35%5%46%16%
2362
16th to endNight
11%14%8%11%8%35%45%421%
1898
March1st to 15thNight
13%10%5%8%424446%34%
2108
16th to endNight
10%11%45%5%3445%7%37%
2088
April1st to 15thNight
19%10%46%433447%32%
1749
16th to endNight
15%10%36%424346%38%
1620
May1st to 15thNight
16%9%35%5%35%45%7%31%
1582
16th to endNight
16%7%34335%35%7%40%
1360
June1st to 15thNight
18%8%35%414446%38%
1260
16th to endNight
14%7%25%5%3446%8%35%
1260
July1st to 15thNight
14%7%26%43345%7%40%
1283
16th to endNight
15%5%245%3445%8%40%
1513
August1st to 15thNight
11%6%15%6%345%5%6%45%
1536
16th to endNight
16%5%145%2335%7%43%
1721
September1st to 15thNight
17%6%35%423447%40%
1872
16th to endNight
22%5%24413447%38%
1980
October1st to 15thNight
23%9%25%5%23446%31%
2076
16th to endNight
28%13%37%5%43335%19%
2496
November1st to 15thNight
23%18%5%7%43433418%
2491
16th to endNight
21%18%6%9%5%35%45%5%14%
2811
December1st to 15thNight
14%21%9%13%7%345%45%11%
2925
16th to endNight
15%22%7%12%8%35%346%10%
3120

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 15thDay
14%19%7%12%6%45%45%5%12%
1444
16th to endDay
11%16%7%12%9%4445%5%18%
1536
February1st to 15thDay
8%16%6%9%10%6%7%5%46%18%
1497
16th to endDay
8%15%7%12%8%45%5%5%6%20%
1573
March1st to 15thDay
13%11%5%8%5%3445%5%31%
1839
16th to endDay
13%11%46%5%25%247%35%
2144
April1st to 15thDay
19%10%35%42445%8%30%
2199
16th to endDay
17%10%36%5%2445%7%33%
2340
May1st to 15thDay
17%8%36%5%34446%33%
2367
16th to endDay
17%6%25%435%45%7%35%
2753
June1st to 15thDay
18%6%35%435%46%8%33%
2700
16th to endDay
16%6%25%5%35%5%6%8%34%
2700
July1st to 15thDay
16%6%245%2445%8%39%
2675
16th to endDay
17%5%2432345%8%40%
2655
August1st to 15thDay
13%6%344345%6%8%40%
2423
16th to endDay
20%6%25%33445%7%37%
2480
September1st to 15thDay
20%6%26%433347%36%
2076
16th to endDay
22%5%25%5%2335%7%35%
1980
October1st to 15thDay
24%12%345%23346%29%
1881
16th to endDay
28%16%47%6%3443317%
1728
November1st to 15thDay
22%18%5%6%5%25%445%18%
1696
16th to endDay
19%20%6%7%6%34445%15%
1478
December1st to 15thDay
13%22%10%12%8%2333414%
1365
16th to endDay
16%24%8%10%5%3435%6%12%
1456
January1st to 15thNight
16%18%8%13%7%3445%6%10%
2736
16th to endNight
11%17%9%11%10%45%445%15%
2688
February1st to 15thNight
8%16%8%13%10%45%46%5%17%
2355
16th to endNight
11%14%8%11%8%36%445%21%
1898
March1st to 15thNight
13%10%5%8%5%24446%34%
2121
16th to endNight
10%11%45%5%3445%7%37%
2088
April1st to 15thNight
18%10%46%5%23446%32%
1749
16th to endNight
14%10%36%424346%38%
1620
May1st to 15thNight
16%9%35%6%35%35%7%32%
1581
16th to endNight
16%7%24335%347%39%
1360
June1st to 15thNight
18%8%35%423346%38%
1260
16th to endNight
14%8%25%5%345%6%9%35%
1260
July1st to 15thNight
14%6%16%42445%8%39%
1283
16th to endNight
15%5%2443445%7%40%
1513
August1st to 15thNight
11%6%145%2445%7%44%
1536
16th to endNight
16%5%235%2435%6%43%
1721
September1st to 15thNight
17%5%35%423447%41%
1872
16th to endNight
22%5%24422447%39%
1980
October1st to 15thNight
23%9%25%5%33446%31%
2076
16th to endNight
28%13%37%6%34335%19%
2496
November1st to 15thNight
23%19%5%8%434335%18%
2491
16th to endNight
20%18%6%9%5%25%5%45%15%
2811
December1st to 15thNight
14%21%8%12%7%345%45%12%
2925
16th to endNight
15%22%6%12%8%35%446%10%
3120

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 15thDay
73%8%9%6%2
1445
16th to endDay
67%8%7%9%5%
1536
February1st to 15thDay
66%7%11%8%5%
1499
16th to endDay
62%6%10%12%7%
1573
March1st to 15thDay
53%6%12%16%9%1
1839
16th to endDay
49%414%19%8%3
2145
April1st to 15thDay
50%5%13%20%9%1
2199
16th to endDay
48%5%9%21%12%3
2340
May1st to 15thDay
49%6%10%19%10%3
2367
16th to endDay
45%7%15%22%9%
2757
June1st to 15thDay
46%6%13%20%11%1
2700
16th to endDay
45%8%14%23%7%
2700
July1st to 15thDay
40%6%16%27%8%
2518
16th to endDay
41%6%16%26%8%
2488
August1st to 15thDay
38%8%21%23%7%
2408
16th to endDay
44%7%16%22%8%
2480
September1st to 15thDay
47%6%17%21%7%
2076
16th to endDay
47%5%18%23%4
1980
October1st to 15thDay
56%5%14%18%3
1881
16th to endDay
71%5%8%9%4
1728
November1st to 15thDay
67%6%9%12%3
1696
16th to endDay
71%8%9%7%2
1478
December1st to 15thDay
75%6%7%7%2
1365
16th to endDay
74%6%8%7%2
1456
January1st to 15thNight
74%9%8%5%2
2736
16th to endNight
70%11%5%7%4
2688
February1st to 15thNight
67%7%11%9%3
2364
16th to endNight
64%6%11%12%5%
1898
March1st to 15thNight
50%5%12%19%11%
2121
16th to endNight
46%5%12%21%11%2
2088
April1st to 15thNight
50%5%10%20%11%
1749
16th to endNight
46%412%18%15%2
1620
May1st to 15thNight
51%411%17%10%3
1582
16th to endNight
44%5%12%24%12%
1362
June1st to 15thNight
46%414%18%14%1
1260
16th to endNight
43%8%15%24%6%
1260
July1st to 15thNight
39%6%14%27%11%
1212
16th to endNight
42%6%13%25%11%
1417
August1st to 15thNight
37%5%20%25%9%
1527
16th to endNight
40%5%17%27%8%
1721
September1st to 15thNight
42%7%16%25%7%
1872
16th to endNight
45%7%16%23%6%
1980
October1st to 15thNight
53%6%13%20%5%
2076
16th to endNight
68%8%9%10%4
2496
November1st to 15thNight
69%5%9%11%3
2491
16th to endNight
71%9%10%6%2
2811
December1st to 15thNight
75%9%8%5%1
2925
16th to endNight
75%7%9%42
3120

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 15thDay
26%12%33%18%8%
106
16th to endDay
21%6%23%32%14%1
96
February1st to 15thDay
30%7%37%18%41
90
16th to endDay
24%18%37%19%
81
March1st to 15thDay
17%17%31%20%11%1
129
16th to endDay
21%8%32%25%9%2
288
April1st to 15thDay
25%5%32%25%8%1
270
16th to endDay
23%7%33%21%9%5%
270
May1st to 15thDay
21%11%29%23%10%4
324
16th to endDay
24%5%27%29%11%2
517
June1st to 15thDay
22%8%29%26%11%2
495
16th to endDay
17%427%31%14%3
495
July1st to 15thDay
17%5%22%36%16%2
475
16th to endDay
20%221%37%14%4
515
August1st to 15thDay
14%420%34%20%5%
396
16th to endDay
28%318%26%16%6%
332
September1st to 15thDay
20%5%22%21%22%6%
315
16th to endDay
23%6%22%31%14%
314
October1st to 15thDay
30%9%22%27%10%
303
16th to endDay
29%15%30%18%4
144
November1st to 15thDay
28%13%28%23%6%
130
16th to endDay
31%17%31%16%3
90
December1st to 15thDay
28%15%30%18%6%
90
16th to endDay
25%19%40%10%4
96
January1st to 15thNight
23%15%35%20%5%
956
16th to endNight
20%9%35%28%5%
960
February1st to 15thNight
17%9%41%25%5%
781
16th to endNight
18%10%32%29%7%1
631
March1st to 15thNight
17%10%38%25%7%
720
16th to endNight
16%8%32%29%10%1
744
April1st to 15thNight
25%6%28%29%8%1
539
16th to endNight
20%6%31%24%15%1
540
May1st to 15thNight
21%424%33%13%2
540
16th to endNight
19%7%21%33%14%3
426
June1st to 15thNight
20%6%18%33%19%1
360
16th to endNight
16%424%32%19%2
360
July1st to 15thNight
17%217%37%22%2
362
16th to endNight
18%216%37%21%3
564
August1st to 15thNight
15%315%34%27%3
539
16th to endNight
19%220%33%20%3
573
September1st to 15thNight
20%5%23%25%18%5%
612
16th to endNight
24%6%20%32%13%2
717
October1st to 15thNight
29%7%28%22%11%
720
16th to endNight
36%11%25%20%5%
768
November1st to 15thNight
33%13%31%17%4
760
16th to endNight
29%14%29%20%5%
861
December1st to 15thNight
24%16%35%17%5%
975
16th to endNight
25%13%32%20%6%
1040
Page generated at 2018-01-12 22:01:31. Version ac04

Copyright 2018 A. Danko


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