Chicoutimi
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Chicoutimi clear sky chart from 2005-11-05 to 2017-08-12.

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
24%
14408
8%
46462
5%
14377
28%
14377
10%
36755

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
15%
729
6%
2560
4%
725
18%
725
4%
2221
January16th to endNight
20%
768
7%
2688
4%
768
24%
768
7%
2217
February1st to 15thNight
21%
703
9%
2409
6%
701
27%
701
9%
1903
February16th to endNight
18%
631
8%
1893
3%
631
24%
631
9%
1556
March1st to 15thNight
23%
720
12%
2159
9%
720
28%
720
13%
1661
March16th to endNight
24%
768
15%
2025
6%
768
30%
768
16%
1541
April1st to 15thNight
24%
697
12%
1775
5%
697
28%
697
14%
1413
April16th to endNight
25%
540
15%
1620
7%
540
33%
540
18%
1145
May1st to 15thNight
27%
421
11%
1501
10%
421
33%
421
13%
1088
May16th to endNight
29%
375
10%
1380
9%
374
35%
374
12%
1004
June1st to 15thNight
32%
360
4%
1260
2%
360
35%
360
14%
907
June16th to endNight
36%
360
4%
1260
3%
360
37%
360
14%
913
July1st to 15thNight
33%
340
6%
1227
4%
340
36%
340
14%
869
July16th to endNight
39%
376
6%
1418
10%
354
40%
354
11%
1035
August1st to 15thNight
40%
379
9%
1428
8%
377
44%
377
12%
1048
August16th to endNight
34%
561
9%
1611
5%
561
37%
561
16%
1229
September1st to 15thNight
35%
660
8%
1691
4%
660
36%
660
19%
1279
September16th to endNight
29%
657
13%
1815
8%
657
32%
657
19%
1336
October1st to 15thNight
25%
660
12%
1930
6%
660
31%
660
14%
1486
October16th to endNight
18%
704
6%
2288
4%
704
21%
704
6%
1939
November1st to 15thNight
20%
700
9%
2277
7%
700
24%
700
8%
1860
November16th to endNight
20%
749
6%
2667
4%
749
23%
749
7%
2212
December1st to 15thNight
13%
750
2%
2700
0%
750
15%
750
3%
2378
December16th to endNight
15%
800
5%
2880
3%
800
19%
800
4%
2515

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
20%10%47%6%35%5%5%6%25%
47520
Night
20%12%5%8%6%35%445%23%
46625
TransparencyDay
59%6%11%14%6%
47201
Night
63%6%10%14%5%
46462
SeeingDay
27%13%27%20%9%1
6049
Night
26%12%27%24%8%
14409

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
16%13%8%11%8%5%6%45%413%
1376
16th to endDay
12%14%6%10%8%46%9%5%5%15%
1536
February1st to 15thDay
8%11%6%9%10%6%9%6%6%5%17%
1450
16th to endDay
11%15%6%9%9%5%8%5%45%18%
1580
March1st to 15thDay
17%10%48%6%35%6%5%6%25%
1790
16th to endDay
15%12%48%5%35%5%46%29%
2198
April1st to 15thDay
21%10%46%6%34445%28%
2173
16th to endDay
20%8%35%5%24346%33%
2340
May1st to 15thDay
22%8%35%434445%33%
2460
16th to endDay
22%6%36%435%5%6%6%29%
2734
June1st to 15thDay
20%7%26%5%35%5%5%6%29%
2700
16th to endDay
20%6%37%7%45%5%5%7%26%
2700
July1st to 15thDay
21%6%26%6%45%6%6%7%24%
2658
16th to endDay
18%6%37%6%35%5%6%6%29%
2654
August1st to 15thDay
20%8%37%7%36%6%5%7%22%
2423
16th to endDay
19%8%37%5%345%5%8%28%
2238
September1st to 15thDay
23%6%36%5%34446%30%
1939
16th to endDay
23%7%25%5%24445%33%
1815
October1st to 15thDay
24%9%36%6%34445%26%
1697
16th to endDay
29%17%47%5%3444316%
1584
November1st to 15thDay
23%13%5%7%6%35%445%20%
1581
16th to endDay
23%19%5%10%5%2433417%
1290
December1st to 15thDay
23%18%5%9%7%37%43411%
1260
16th to endDay
21%19%6%9%7%36%43413%
1344
January1st to 15thNight
18%15%7%12%10%46%44411%
2560
16th to endNight
12%15%7%8%9%48%6%6%5%13%
2688
February1st to 15thNight
8%11%6%11%10%6%7%46%421%
2408
16th to endNight
12%18%7%11%8%4434420%
1893
March1st to 15thNight
17%13%5%7%5%35%445%26%
2146
16th to endNight
13%13%6%7%5%34335%32%
2025
April1st to 15thNight
24%12%47%5%2443426%
1775
16th to endNight
21%8%26%324446%35%
1620
May1st to 15thNight
23%9%46%5%23345%29%
1501
16th to endNight
22%8%36%5%34445%28%
1378
June1st to 15thNight
21%8%45%5%35%5%47%28%
1260
16th to endNight
19%5%36%6%45%5%49%27%
1260
July1st to 15thNight
18%6%37%6%45%6%6%8%26%
1300
16th to endNight
17%7%35%7%46%47%7%28%
1514
August1st to 15thNight
18%7%46%6%45%5%5%7%27%
1438
16th to endNight
21%6%36%6%25%6%5%6%28%
1611
September1st to 15thNight
22%6%36%5%3335%6%32%
1691
16th to endNight
25%5%25%6%3344435%
1815
October1st to 15thNight
25%7%35%6%34436%29%
1930
16th to endNight
31%15%36%5%3334417%
2288
November1st to 15thNight
25%16%47%6%3333420%
2277
16th to endNight
22%16%5%10%5%2434418%
2667
December1st to 15thNight
23%18%6%11%7%35%43411%
2700
16th to endNight
17%19%7%10%9%46%5%4411%
2880

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
71%7%9%8%2
1377
16th to endDay
66%7%7%13%5%
1536
February1st to 15thDay
66%8%9%10%41
1453
16th to endDay
68%5%7%12%5%
1580
March1st to 15thDay
60%5%9%14%8%
1800
16th to endDay
56%5%11%18%8%
2198
April1st to 15thDay
59%49%16%8%1
2173
16th to endDay
52%5%11%18%11%1
2340
May1st to 15thDay
53%412%17%11%1
2460
16th to endDay
55%7%8%18%8%1
2738
June1st to 15thDay
54%5%11%16%10%1
2700
16th to endDay
55%8%11%16%7%
2700
July1st to 15thDay
55%8%15%16%3
2502
16th to endDay
56%8%13%17%4
2487
August1st to 15thDay
59%9%16%11%2
2409
16th to endDay
53%8%18%16%2
2238
September1st to 15thDay
55%5%15%18%5%
1939
16th to endDay
52%6%17%18%5%
1815
October1st to 15thDay
61%5%12%14%6%
1697
16th to endDay
73%6%8%9%1
1584
November1st to 15thDay
66%6%9%12%3
1581
16th to endDay
71%7%11%8%1
1290
December1st to 15thDay
76%5%9%7%1
1260
16th to endDay
75%6%6%7%4
1344
January1st to 15thNight
75%6%7%8%2
2560
16th to endNight
69%6%7%13%3
2688
February1st to 15thNight
63%6%9%14%5%
2409
16th to endNight
68%48%13%4
1893
March1st to 15thNight
60%48%16%8%
2159
16th to endNight
56%5%7%20%8%1
2025
April1st to 15thNight
62%47%13%10%1
1775
16th to endNight
51%410%19%13%1
1620
May1st to 15thNight
58%38%16%11%
1501
16th to endNight
56%5%9%16%9%1
1380
June1st to 15thNight
54%6%12%16%9%
1260
16th to endNight
53%7%11%16%8%1
1260
July1st to 15thNight
52%7%15%18%4
1227
16th to endNight
54%10%10%19%5%
1418
August1st to 15thNight
54%9%16%16%3
1428
16th to endNight
54%9%14%17%3
1611
September1st to 15thNight
52%6%14%18%7%
1691
16th to endNight
52%6%13%21%5%
1815
October1st to 15thNight
57%6%11%16%5%1
1930
16th to endNight
72%5%7%10%3
2288
November1st to 15thNight
68%5%10%10%4
2277
16th to endNight
69%6%11%9%2
2667
December1st to 15thNight
77%6%8%6%1
2700
16th to endNight
76%6%6%7%2
2880

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
18%28%38%13%1
60
16th to endDay
28%15%28%23%4
64
February1st to 15thDay
19%13%39%17%8%3
99
16th to endDay
28%16%27%19%7%
239
March1st to 15thDay
30%15%26%18%9%
270
16th to endDay
23%16%28%22%8%1
288
April1st to 15thDay
27%15%26%20%8%1
270
16th to endDay
26%15%30%15%10%1
270
May1st to 15thDay
28%12%28%20%8%1
288
16th to endDay
26%15%31%18%7%
447
June1st to 15thDay
26%10%26%23%10%1
495
16th to endDay
23%9%31%21%11%2
495
July1st to 15thDay
27%8%26%23%13%1
436
16th to endDay
21%9%27%25%12%2
326
August1st to 15thDay
26%8%23%22%14%4
297
16th to endDay
24%13%22%23%11%4
268
September1st to 15thDay
28%12%23%19%10%5%
255
16th to endDay
25%15%24%18%11%4
254
October1st to 15thDay
31%12%25%17%11%2
245
16th to endDay
43%11%22%14%5%2
240
November1st to 15thDay
33%15%24%17%7%1
235
16th to endDay
47%15%21%13%2
84
December1st to 15thDay
31%11%45%6%5%
60
16th to endDay
34%28%29%6%1
64
January1st to 15thNight
26%13%31%22%6%
729
16th to endNight
20%13%30%26%7%1
768
February1st to 15thNight
13%14%36%26%7%
704
16th to endNight
24%15%31%19%8%1
631
March1st to 15thNight
26%15%29%22%6%
720
16th to endNight
21%15%29%24%7%
768
April1st to 15thNight
30%14%25%22%6%
697
16th to endNight
24%11%32%22%7%
540
May1st to 15thNight
29%10%26%24%8%
421
16th to endNight
25%11%28%27%7%
375
June1st to 15thNight
22%6%31%30%7%
360
16th to endNight
19%8%29%32%9%
360
July1st to 15thNight
21%8%26%31%10%
340
16th to endNight
18%6%26%35%13%
376
August1st to 15thNight
20%7%20%31%18%1
379
16th to endNight
24%6%25%30%12%1
561
September1st to 15thNight
27%8%22%29%10%1
660
16th to endNight
27%9%28%22%9%1
657
October1st to 15thNight
28%11%27%21%10%
660
16th to endNight
39%14%21%16%7%
704
November1st to 15thNight
32%17%21%18%8%1
700
16th to endNight
29%16%25%19%7%1
749
December1st to 15thNight
33%15%25%18%5%
750
16th to endNight
27%17%23%22%7%1
800
Page generated at 2017-08-13 14:16:17. Version ac04

Copyright 2017 A. Danko


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