Shawinigan
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Shawinigan 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
29%
22539
14%
74918
8%
22498
38%
22498
17%
52600

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
18%
760
10%
2649
3%
757
26%
757
9%
2077
January11th to 20thNight
18%
744
11%
2602
5%
744
27%
744
11%
1974
January21st to endNight
28%
792
15%
2772
8%
792
38%
792
15%
1944
February1st to 10thNight
21%
720
13%
2453
4%
720
31%
720
13%
1790
February11th to 20thNight
19%
703
13%
2161
5%
700
30%
700
14%
1607
February21st to endNight
25%
592
18%
1776
9%
592
38%
592
17%
1287
March1st to 10thNight
24%
720
15%
2160
9%
720
32%
720
15%
1602
March11th to 20thNight
23%
720
16%
2111
5%
720
33%
720
16%
1540
March21st to endNight
28%
792
21%
1980
6%
792
37%
792
21%
1426
April1st to 10thNight
25%
720
15%
1800
4%
720
30%
720
19%
1357
April11th to 20thNight
27%
685
18%
1749
6%
685
35%
685
23%
1220
April21st to endNight
24%
540
17%
1620
7%
540
34%
540
18%
1141
May1st to 10thNight
27%
432
16%
1512
10%
432
39%
432
16%
1033
May11th to 20thNight
32%
354
19%
1416
16%
354
46%
354
17%
890
May21st to endNight
29%
389
13%
1551
10%
388
43%
388
18%
993
June1st to 10thNight
35%
360
9%
1440
8%
360
44%
360
18%
928
June11th to 20thNight
39%
360
10%
1440
11%
360
44%
360
17%
917
June21st to endNight
41%
360
8%
1440
9%
360
45%
360
16%
952
July1st to 10thNight
44%
350
10%
1400
12%
350
51%
350
21%
850
July11th to 20thNight
49%
348
12%
1392
18%
348
53%
348
22%
850
July21st to endNight
50%
394
13%
1486
16%
372
55%
372
21%
902
August1st to 10thNight
58%
358
15%
1422
17%
356
63%
356
24%
837
August11th to 20thNight
50%
467
15%
1531
12%
467
53%
467
25%
967
August21st to endNight
45%
787
19%
1975
9%
787
49%
787
31%
1316
September1st to 10thNight
44%
720
15%
1800
5%
720
49%
720
34%
1192
September11th to 20thNight
44%
720
19%
1908
10%
720
50%
720
34%
1190
September21st to endNight
40%
720
22%
1980
14%
720
46%
720
29%
1296
October1st to 10thNight
33%
720
22%
2055
12%
720
44%
720
23%
1395
October11th to 20thNight
30%
720
15%
2253
8%
720
39%
720
19%
1597
October21st to endNight
24%
792
11%
2574
6%
792
32%
792
16%
1857
November1st to 10thNight
26%
740
16%
2407
7%
740
37%
740
16%
1677
November11th to 20thNight
26%
760
18%
2531
11%
760
37%
760
15%
1815
November21st to endNight
24%
760
13%
2660
7%
760
33%
760
12%
1956
December1st to 10thNight
20%
809
11%
2762
4%
809
28%
809
11%
2131
December11th to 20thNight
18%
804
12%
3329
5%
804
27%
804
9%
2496
December21st to endNight
16%
827
9%
4821
4%
817
25%
817
6%
3598

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%47%6%35%5%5%7%32%
74566
Night
19%10%47%6%3445%6%33%
75208
TransparencyDay
53%412%21%10%1
74272
Night
54%311%21%10%1
75037
SeeingDay
24%11%31%22%10%2
13437
Night
25%8%29%29%9%1
22549

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
18%14%6%11%7%35%44424%
1517
11th to 20thDay
17%15%6%9%7%45%445%25%
1480
21st to endDay
11%12%6%9%8%46%5%5%5%30%
1584
February1st to 10thDay
13%16%6%10%8%46%335%26%
1503
11th to 20thDay
14%15%5%9%7%4445%5%28%
1686
21st to endDay
15%14%6%9%8%45%435%28%
1480
March1st to 10thDay
14%11%5%9%6%46%446%31%
1797
11th to 20thDay
17%12%46%6%45%5%45%32%
1843
21st to endDay
16%11%37%7%45%5%45%33%
2376
April1st to 10thDay
23%11%46%5%3435%5%30%
2160
11th to 20thDay
21%7%26%5%34446%37%
2160
21st to endDay
23%10%46%5%35%446%30%
2340
May1st to 10thDay
23%8%26%5%34446%35%
2465
11th to 20thDay
19%6%36%5%4445%7%35%
2478
21st to endDay
20%7%26%6%35%5%5%7%33%
2725
June1st to 10thDay
21%7%37%5%46%5%6%7%28%
2520
11th to 20thDay
18%7%36%5%35%5%6%8%34%
2520
21st to endDay
22%8%47%6%46%5%5%6%28%
2520
July1st to 10thDay
15%5%26%6%37%6%7%8%34%
2520
11th to 20thDay
15%6%36%6%46%6%7%9%33%
2520
21st to endDay
15%5%36%7%46%6%7%8%32%
2744
August1st to 10thDay
16%6%36%7%46%6%8%10%29%
2506
11th to 20thDay
14%5%25%6%45%6%7%9%36%
2351
21st to endDay
13%7%25%436%6%7%9%39%
2377
September1st to 10thDay
16%5%345%35%5%5%8%41%
2160
11th to 20thDay
16%6%244235%5%8%44%
2052
21st to endDay
22%7%25%424446%41%
1980
October1st to 10thDay
22%7%45%5%34447%34%
1904
11th to 20thDay
23%8%37%8%445%5%6%26%
1706
21st to endDay
27%11%46%435%346%27%
1782
November1st to 10thDay
18%11%45%6%45%5%46%33%
1671
11th to 20thDay
22%12%46%7%35%345%29%
1645
21st to endDay
21%15%46%6%345%45%27%
1520
December1st to 10thDay
24%15%47%6%4434424%
1406
11th to 20thDay
22%14%5%8%5%34345%27%
1796
21st to endDay
23%18%6%8%5%3433423%
2772
January1st to 10thNight
19%16%7%9%6%35%45%5%21%
2649
11th to 20thNight
17%17%6%8%6%34435%26%
2602
21st to endNight
12%11%5%9%7%45%446%32%
2772
February1st to 10thNight
12%14%5%10%8%45%45%5%28%
2453
11th to 20thNight
13%15%411%8%44445%29%
2159
21st to endNight
16%10%5%9%6%45%45%432%
1776
March1st to 10thNight
16%11%410%8%35%45%5%29%
2150
11th to 20thNight
18%12%47%5%35%5%45%31%
2111
21st to endNight
16%11%37%5%35%44437%
1980
April1st to 10thNight
23%11%46%43445%6%30%
1800
11th to 20thNight
20%7%36%5%2445%6%38%
1749
21st to endNight
24%8%45%5%2445%6%34%
1620
May1st to 10thNight
22%8%35%5%34445%36%
1512
11th to 20thNight
20%6%25%5%35%46%7%36%
1415
21st to endNight
19%6%36%6%35%347%38%
1550
June1st to 10thNight
21%6%25%5%35%5%5%8%34%
1440
11th to 20thNight
20%6%26%435%5%5%8%36%
1440
21st to endNight
19%6%37%5%35%5%7%7%33%
1440
July1st to 10thNight
14%6%35%7%45%47%8%39%
1440
11th to 20thNight
14%6%26%6%35%5%6%7%40%
1440
21st to endNight
14%5%25%6%36%5%6%9%39%
1574
August1st to 10thNight
13%415%5%45%6%7%9%42%
1432
11th to 20thNight
14%6%36%6%345%6%7%41%
1531
21st to endNight
16%6%245%34447%45%
1975
September1st to 10thNight
14%5%25%5%35%46%6%45%
1800
11th to 20thNight
16%5%24423446%49%
1908
21st to endNight
19%6%24423446%46%
1980
October1st to 10thNight
18%8%25%5%245%45%41%
2055
11th to 20thNight
23%8%36%5%34446%34%
2253
21st to endNight
26%8%36%5%345%46%31%
2574
November1st to 10thNight
18%11%46%6%3445%5%34%
2407
11th to 20thNight
21%9%46%6%4445%5%31%
2531
21st to endNight
23%13%46%6%34445%29%
2660
December1st to 10thNight
22%14%5%8%7%35%445%24%
2762
11th to 20thNight
23%12%5%9%7%33435%26%
3384
21st to endNight
23%19%6%8%42333325%
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
65%29%17%7%
1518
11th to 20thDay
64%38%16%8%1
1480
21st to endDay
57%38%21%11%2
1584
February1st to 10thDay
62%29%17%8%2
1503
11th to 20thDay
60%212%14%11%1
1695
21st to endDay
61%28%17%10%2
1480
March1st to 10thDay
57%210%17%12%2
1800
11th to 20thDay
55%310%16%14%3
1843
21st to endDay
54%38%20%12%3
2376
April1st to 10thDay
58%39%16%12%3
2160
11th to 20thDay
49%310%23%13%3
2160
21st to endDay
56%39%17%12%3
2340
May1st to 10thDay
51%38%21%14%3
2465
11th to 20thDay
49%39%22%15%2
2482
21st to endDay
52%310%19%14%2
2725
June1st to 10thDay
54%410%20%9%2
2520
11th to 20thDay
48%411%24%12%2
2520
21st to endDay
57%5%11%18%10%1
2520
July1st to 10thDay
44%5%16%26%9%
2450
11th to 20thDay
45%5%16%25%9%
2445
21st to endDay
49%5%16%22%7%
2591
August1st to 10thDay
48%6%19%21%5%
2492
11th to 20thDay
43%6%18%24%9%
2351
21st to endDay
41%415%27%11%1
2377
September1st to 10thDay
41%317%25%12%1
2160
11th to 20thDay
40%317%29%11%1
2052
21st to endDay
45%414%27%10%
1980
October1st to 10thDay
51%311%25%9%
1904
11th to 20thDay
59%412%21%4
1706
21st to endDay
60%312%17%8%1
1782
November1st to 10thDay
54%312%20%9%1
1671
11th to 20thDay
59%311%18%9%
1645
21st to endDay
60%6%11%18%5%1
1520
December1st to 10thDay
65%210%18%5%
1406
11th to 20thDay
62%27%22%7%
1797
21st to endDay
67%28%14%7%1
2772
January1st to 10thNight
67%29%16%5%
2649
11th to 20thNight
64%210%14%9%1
2602
21st to endNight
56%39%19%13%1
2772
February1st to 10thNight
59%39%18%9%1
2453
11th to 20thNight
59%310%17%11%1
2161
21st to endNight
56%37%18%14%2
1776
March1st to 10thNight
59%38%18%11%2
2160
11th to 20thNight
56%39%16%13%3
2112
21st to endNight
51%37%22%14%4
1980
April1st to 10thNight
56%28%18%13%2
1800
11th to 20thNight
47%39%24%15%2
1749
21st to endNight
52%47%20%15%3
1620
May1st to 10thNight
53%38%17%16%4
1512
11th to 20thNight
48%210%20%15%4
1416
21st to endNight
47%411%19%17%2
1551
June1st to 10thNight
48%413%21%12%1
1440
11th to 20thNight
47%410%21%13%4
1440
21st to endNight
49%5%13%19%13%
1440
July1st to 10thNight
44%416%24%12%1
1400
11th to 20thNight
43%416%26%10%1
1392
21st to endNight
43%417%26%10%
1486
August1st to 10thNight
39%6%19%29%7%
1422
11th to 20thNight
44%318%26%9%
1531
21st to endNight
41%315%30%11%
1975
September1st to 10thNight
39%416%27%13%1
1800
11th to 20thNight
37%318%31%10%1
1908
21st to endNight
42%311%31%13%
1980
October1st to 10thNight
46%49%27%13%
2055
11th to 20thNight
53%313%24%7%
2253
21st to endNight
56%313%19%9%
2574
November1st to 10thNight
53%412%22%8%1
2407
11th to 20thNight
56%411%20%9%1
2531
21st to endNight
60%311%18%8%
2660
December1st to 10thNight
65%211%16%5%
2762
11th to 20thNight
64%27%19%8%
3384
21st to endNight
67%17%18%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
29%11%36%18%5%1
180
11th to 20thDay
28%10%35%21%5%1
170
21st to endDay
17%11%40%21%10%1
176
February1st to 10thDay
30%20%37%12%11
188
11th to 20thDay
25%15%39%17%3
354
21st to endDay
26%13%37%19%5%
346
March1st to 10thDay
25%13%34%21%6%
420
11th to 20thDay
25%17%34%17%6%1
420
21st to endDay
27%15%27%20%8%2
462
April1st to 10thDay
30%11%29%23%7%
420
11th to 20thDay
26%14%31%20%6%3
412
21st to endDay
30%12%36%15%5%2
420
May1st to 10thDay
28%13%33%18%7%1
423
11th to 20thDay
21%13%32%24%8%2
447
21st to endDay
23%14%35%17%9%1
485
June1st to 10thDay
23%11%36%21%8%2
450
11th to 20thDay
22%12%30%23%11%3
450
21st to endDay
25%8%29%24%11%2
450
July1st to 10thDay
16%9%30%30%13%3
445
11th to 20thDay
16%6%30%34%12%2
444
21st to endDay
17%6%28%29%16%4
488
August1st to 10thDay
18%5%23%32%17%3
446
11th to 20thDay
17%323%34%17%6%
439
21st to endDay
17%10%27%22%17%6%
495
September1st to 10thDay
19%8%33%22%14%5%
450
11th to 20thDay
19%9%24%26%15%7%
450
21st to endDay
23%10%25%23%12%7%
450
October1st to 10thDay
25%10%28%22%13%2
450
11th to 20thDay
27%11%30%21%10%1
403
21st to endDay
35%9%29%20%8%
396
November1st to 10thDay
26%13%30%24%7%1
365
11th to 20thDay
28%12%31%21%7%
305
21st to endDay
27%19%31%16%6%2
180
December1st to 10thDay
34%11%29%18%7%1
180
11th to 20thDay
29%15%34%17%32
180
21st to endDay
34%15%29%16%5%1
198
January1st to 10thNight
30%8%31%26%4
760
11th to 20thNight
29%10%31%23%7%
744
21st to endNight
18%7%33%34%6%1
792
February1st to 10thNight
20%10%36%27%6%1
720
11th to 20thNight
23%11%37%23%5%1
703
21st to endNight
24%10%32%27%7%
592
March1st to 10thNight
24%10%33%30%4
720
11th to 20thNight
24%12%33%25%5%1
720
21st to endNight
23%12%31%25%8%1
792
April1st to 10thNight
30%10%27%25%7%
720
11th to 20thNight
26%12%29%27%6%
685
21st to endNight
29%12%30%24%5%
540
May1st to 10thNight
29%10%27%27%7%
432
11th to 20thNight
23%8%30%30%8%
354
21st to endNight
23%5%34%28%10%
389
June1st to 10thNight
24%429%34%8%1
360
11th to 20thNight
23%5%22%38%10%1
360
21st to endNight
20%423%38%14%
360
July1st to 10thNight
15%427%38%16%1
350
11th to 20thNight
15%125%42%16%1
348
21st to endNight
18%320%41%17%1
394
August1st to 10thNight
15%217%47%19%1
358
11th to 20thNight
18%419%38%20%2
467
21st to endNight
19%5%24%33%18%1
787
September1st to 10thNight
17%428%36%14%1
720
11th to 20thNight
19%6%24%31%19%1
720
21st to endNight
23%5%27%27%16%2
720
October1st to 10thNight
22%9%28%31%9%1
720
11th to 20thNight
26%8%27%28%10%1
720
21st to endNight
32%7%30%25%6%
792
November1st to 10thNight
26%9%30%27%7%1
740
11th to 20thNight
27%10%29%23%11%1
760
21st to endNight
32%11%25%26%6%1
760
December1st to 10thNight
30%8%28%25%8%
809
11th to 20thNight
29%9%31%23%6%1
805
21st to endNight
33%11%28%23%5%
836
Page generated at 2024-01-13 09:37:59. Version ac07

Copyright 2024 Attilla Danko


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