Candiac
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Candiac clear sky chart from 2005-11-06 to 2024-01-22.

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%
22596
14%
74846
8%
22555
36%
22555
16%
53520

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
16%
760
9%
2649
4%
757
23%
757
8%
2121
January11th to 20thNight
16%
760
9%
2660
4%
760
24%
760
9%
2077
January21st to endNight
21%
800
12%
2798
6%
800
29%
800
12%
2035
February1st to 10thNight
17%
720
9%
2383
3%
720
25%
720
9%
1898
February11th to 20thNight
21%
702
12%
2170
4%
700
30%
700
13%
1604
February21st to endNight
24%
592
16%
1776
6%
592
36%
592
15%
1308
March1st to 10thNight
23%
720
15%
2160
10%
720
31%
720
15%
1606
March11th to 20thNight
23%
720
15%
2100
7%
720
31%
720
16%
1551
March21st to endNight
28%
792
21%
1980
8%
792
36%
792
22%
1444
April1st to 10thNight
25%
720
16%
1800
4%
720
31%
720
18%
1361
April11th to 20thNight
26%
711
15%
1775
4%
711
32%
711
21%
1309
April21st to endNight
27%
568
17%
1648
8%
568
34%
568
18%
1181
May1st to 10thNight
28%
429
16%
1509
11%
429
37%
429
16%
1038
May11th to 20thNight
33%
354
19%
1416
17%
354
44%
354
18%
897
May21st to endNight
35%
388
14%
1551
11%
388
46%
388
19%
963
June1st to 10thNight
31%
360
11%
1440
10%
360
42%
360
15%
979
June11th to 20thNight
38%
360
11%
1440
12%
360
47%
360
19%
891
June21st to endNight
40%
360
10%
1440
12%
360
48%
360
16%
959
July1st to 10thNight
47%
350
14%
1400
18%
350
54%
350
23%
826
July11th to 20thNight
53%
348
14%
1392
20%
348
57%
348
24%
825
July21st to endNight
50%
394
14%
1486
14%
372
56%
372
21%
888
August1st to 10thNight
59%
358
17%
1422
20%
356
61%
356
22%
829
August11th to 20thNight
51%
538
17%
1602
12%
538
55%
538
28%
1029
August21st to endNight
51%
792
19%
1980
10%
792
53%
792
31%
1331
September1st to 10thNight
47%
720
16%
1800
8%
720
50%
720
31%
1213
September11th to 20thNight
50%
720
20%
1883
12%
720
53%
720
33%
1206
September21st to endNight
41%
720
21%
1980
14%
720
46%
720
27%
1319
October1st to 10thNight
35%
720
18%
2086
12%
720
43%
720
23%
1428
October11th to 20thNight
30%
720
16%
2204
9%
720
38%
720
17%
1586
October21st to endNight
23%
792
12%
2574
6%
792
31%
792
14%
1900
November1st to 10thNight
22%
740
16%
2407
9%
740
33%
740
15%
1692
November11th to 20thNight
24%
760
17%
2527
11%
760
33%
760
15%
1794
November21st to endNight
19%
760
11%
2660
5%
760
27%
760
10%
2024
December1st to 10thNight
16%
760
8%
2660
4%
760
21%
760
8%
2142
December11th to 20thNight
15%
760
11%
3242
4%
759
24%
759
8%
2481
December21st to endNight
14%
828
6%
4846
3%
817
21%
817
5%
3785

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
18%9%37%6%35%5%5%7%33%
74839
Night
19%10%47%6%3445%6%31%
75102
TransparencyDay
51%5%12%21%10%1
74544
Night
54%5%10%19%10%1
74931
SeeingDay
22%11%29%23%11%3
13506
Night
24%9%29%27%10%1
22606

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
20%17%6%10%8%45%42421%
1517
11th to 20thDay
19%14%5%11%8%3445%5%23%
1520
21st to endDay
12%14%47%7%45%6%6%7%26%
1592
February1st to 10thDay
16%14%5%10%8%46%345%24%
1575
11th to 20thDay
15%12%5%9%8%46%5%5%5%27%
1678
21st to endDay
18%14%6%6%7%44446%27%
1480
March1st to 10thDay
16%12%49%7%36%45%5%28%
1797
11th to 20thDay
16%11%47%7%45%45%6%32%
1857
21st to endDay
19%10%47%5%25%446%34%
2376
April1st to 10thDay
22%10%37%5%34445%32%
2160
11th to 20thDay
20%8%35%6%23446%38%
2134
21st to endDay
22%9%37%5%35%5%5%6%31%
2311
May1st to 10thDay
20%8%36%5%45%447%34%
2466
11th to 20thDay
17%7%25%5%345%5%7%39%
2478
21st to endDay
17%6%27%5%35%5%6%8%36%
2725
June1st to 10thDay
22%6%35%6%35%5%6%8%31%
2520
11th to 20thDay
15%6%35%5%445%5%9%40%
2520
21st to endDay
19%7%37%6%35%5%5%8%33%
2520
July1st to 10thDay
12%5%35%5%45%5%6%9%41%
2520
11th to 20thDay
12%5%35%6%35%6%6%10%38%
2520
21st to endDay
12%6%35%5%36%6%7%9%38%
2744
August1st to 10thDay
13%5%36%5%36%5%7%9%38%
2506
11th to 20thDay
10%5%35%6%35%5%7%9%42%
2279
21st to endDay
13%6%345%35%5%6%9%43%
2376
September1st to 10thDay
12%435%6%35%5%6%8%43%
2160
11th to 20thDay
15%5%2432445%6%49%
2076
21st to endDay
15%6%25%6%35%5%6%8%41%
1980
October1st to 10thDay
20%6%37%6%45%46%7%32%
1872
11th to 20thDay
18%8%38%8%45%5%6%6%29%
1756
21st to endDay
27%10%36%5%3445%5%29%
1782
November1st to 10thDay
19%10%37%5%435%6%6%32%
1671
11th to 20thDay
18%10%5%8%6%46%5%5%6%27%
1653
21st to endDay
23%11%5%8%7%45%5%5%6%22%
1520
December1st to 10thDay
24%14%8%8%8%44446%18%
1520
11th to 20thDay
22%14%5%8%5%345%46%23%
1906
21st to endDay
28%14%5%10%6%3443419%
2772
January1st to 10thNight
18%17%6%9%7%45%445%20%
2649
11th to 20thNight
17%16%6%10%6%45%5%5%5%22%
2660
21st to endNight
14%12%6%8%8%4445%5%29%
2798
February1st to 10thNight
16%15%6%12%8%46%445%20%
2383
11th to 20thNight
16%10%5%9%6%5%5%5%5%6%28%
2168
21st to endNight
17%13%5%8%6%4434432%
1776
March1st to 10thNight
18%14%48%6%45%45%5%28%
2150
11th to 20thNight
19%12%47%6%44346%31%
2100
21st to endNight
18%10%45%6%34345%37%
1980
April1st to 10thNight
25%9%36%6%35%35%7%29%
1800
11th to 20thNight
23%8%37%4335%5%6%34%
1775
21st to endNight
22%9%36%6%35%45%5%34%
1648
May1st to 10thNight
21%9%36%6%2435%6%35%
1509
11th to 20thNight
19%7%46%5%25%447%37%
1415
21st to endNight
16%5%35%5%445%6%7%40%
1550
June1st to 10thNight
22%7%36%5%25%47%7%32%
1440
11th to 20thNight
17%6%26%5%35%46%7%39%
1440
21st to endNight
17%6%36%7%46%5%5%8%34%
1440
July1st to 10thNight
12%5%36%6%35%6%6%8%42%
1440
11th to 20thNight
10%5%345%45%7%8%9%39%
1440
21st to endNight
12%5%35%6%45%5%6%10%39%
1574
August1st to 10thNight
13%435%5%35%5%6%9%43%
1432
11th to 20thNight
13%5%26%5%35%5%5%8%42%
1602
21st to endNight
13%6%26%4445%5%8%43%
1980
September1st to 10thNight
13%5%37%6%345%5%6%44%
1800
11th to 20thNight
16%5%25%5%23447%48%
1883
21st to endNight
17%6%25%435%446%43%
1980
October1st to 10thNight
18%6%36%6%445%46%37%
2086
11th to 20thNight
22%8%27%6%35%5%5%5%32%
2204
21st to endNight
24%9%47%5%345%45%29%
2574
November1st to 10thNight
19%10%46%6%35%45%6%31%
2407
11th to 20thNight
20%9%48%6%34346%32%
2527
21st to endNight
23%12%48%6%35%45%5%24%
2660
December1st to 10thNight
22%16%8%9%6%44445%18%
2660
11th to 20thNight
23%15%5%8%6%33445%24%
3288
21st to endNight
28%15%6%8%5%2334421%
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
69%38%15%4
1518
11th to 20thDay
66%48%13%9%
1520
21st to endDay
56%5%12%17%9%1
1592
February1st to 10thDay
64%39%19%5%1
1575
11th to 20thDay
58%5%11%18%7%1
1687
21st to endDay
60%410%15%9%1
1480
March1st to 10thDay
57%6%9%17%9%2
1800
11th to 20thDay
52%412%16%12%2
1857
21st to endDay
52%6%8%20%13%3
2376
April1st to 10thDay
55%5%7%19%12%2
2160
11th to 20thDay
48%5%8%23%15%2
2134
21st to endDay
53%410%17%12%3
2311
May1st to 10thDay
50%5%7%20%16%2
2466
11th to 20thDay
45%5%10%22%16%3
2482
21st to endDay
46%6%13%20%13%2
2725
June1st to 10thDay
51%5%11%20%11%2
2520
11th to 20thDay
43%6%10%25%14%3
2520
21st to endDay
51%5%12%21%10%1
2520
July1st to 10thDay
38%7%13%29%13%1
2450
11th to 20thDay
39%8%14%30%9%
2445
21st to endDay
42%7%16%26%9%
2591
August1st to 10thDay
42%7%17%26%9%
2492
11th to 20thDay
37%7%18%27%11%
2279
21st to endDay
38%6%16%26%14%1
2376
September1st to 10thDay
38%6%15%28%13%
2160
11th to 20thDay
35%5%12%33%14%1
2076
21st to endDay
41%5%15%27%10%1
1980
October1st to 10thDay
51%5%12%22%10%
1872
11th to 20thDay
53%7%13%19%7%
1756
21st to endDay
58%412%18%7%1
1782
November1st to 10thDay
51%5%14%21%9%1
1671
11th to 20thDay
57%5%10%16%11%
1653
21st to endDay
61%7%12%13%5%
1520
December1st to 10thDay
69%6%9%12%4
1520
11th to 20thDay
62%6%13%15%5%
1906
21st to endDay
69%7%10%10%4
2772
January1st to 10thNight
67%5%8%14%5%
2649
11th to 20thNight
65%5%10%13%6%1
2660
21st to endNight
58%410%16%11%1
2798
February1st to 10thNight
67%48%15%6%1
2383
11th to 20thNight
58%411%19%8%1
2170
21st to endNight
58%38%18%12%1
1776
March1st to 10thNight
58%39%18%10%2
2160
11th to 20thNight
56%48%17%12%3
2101
21st to endNight
51%37%21%14%4
1980
April1st to 10thNight
56%47%18%14%2
1800
11th to 20thNight
52%48%21%14%2
1775
21st to endNight
53%48%18%14%4
1648
May1st to 10thNight
52%46%18%16%5%
1509
11th to 20thNight
47%48%18%18%4
1416
21st to endNight
43%6%11%21%16%3
1551
June1st to 10thNight
51%6%9%21%11%1
1440
11th to 20thNight
43%7%11%22%14%3
1440
21st to endNight
48%7%11%21%13%1
1440
July1st to 10thNight
38%7%12%25%17%1
1400
11th to 20thNight
36%8%14%29%13%
1392
21st to endNight
39%7%17%25%10%1
1486
August1st to 10thNight
38%7%17%26%12%
1422
11th to 20thNight
39%6%17%23%14%1
1602
21st to endNight
40%6%12%28%13%1
1980
September1st to 10thNight
41%5%11%27%15%1
1800
11th to 20thNight
38%413%31%13%1
1883
21st to endNight
43%5%11%26%15%1
1980
October1st to 10thNight
47%412%24%12%1
2086
11th to 20thNight
53%6%10%24%8%
2204
21st to endNight
57%5%12%16%9%1
2574
November1st to 10thNight
53%411%21%9%1
2407
11th to 20thNight
54%411%19%10%1
2527
21st to endNight
62%411%17%6%
2660
December1st to 10thNight
69%311%13%3
2660
11th to 20thNight
64%49%16%6%
3288
21st to endNight
68%410%14%4
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
31%14%28%17%9%1
180
11th to 20thDay
27%16%35%18%41
180
21st to endDay
24%13%35%19%8%1
178
February1st to 10thDay
33%20%35%11%
220
11th to 20thDay
24%18%37%19%31
346
21st to endDay
28%15%27%26%3
346
March1st to 10thDay
26%11%36%21%6%
420
11th to 20thDay
22%17%34%20%7%1
420
21st to endDay
29%14%28%19%8%2
462
April1st to 10thDay
32%12%28%17%8%2
420
11th to 20thDay
30%17%24%15%11%3
412
21st to endDay
29%10%30%20%10%1
420
May1st to 10thDay
25%11%32%20%10%2
423
11th to 20thDay
19%11%32%26%10%4
447
21st to endDay
19%12%33%23%11%2
485
June1st to 10thDay
26%10%27%26%9%2
450
11th to 20thDay
16%11%28%28%14%2
450
21st to endDay
21%9%29%24%14%3
450
July1st to 10thDay
12%7%27%30%20%4
445
11th to 20thDay
14%6%30%31%14%5%
444
21st to endDay
15%6%28%30%19%3
488
August1st to 10thDay
15%425%31%19%5%
446
11th to 20thDay
12%423%33%17%9%
439
21st to endDay
14%9%24%27%16%10%
495
September1st to 10thDay
14%5%28%29%16%8%
450
11th to 20thDay
17%8%22%24%18%11%
450
21st to endDay
15%8%30%24%16%7%
450
October1st to 10thDay
22%11%30%19%14%4
450
11th to 20thDay
21%16%30%19%11%1
428
21st to endDay
36%11%24%23%6%
396
November1st to 10thDay
28%13%26%25%8%1
365
11th to 20thDay
25%19%32%15%7%1
313
21st to endDay
30%12%33%19%6%1
180
December1st to 10thDay
36%9%24%23%6%2
180
11th to 20thDay
28%22%34%12%4
180
21st to endDay
31%19%27%17%5%2
198
January1st to 10thNight
28%12%33%22%5%
760
11th to 20thNight
26%12%35%20%6%
760
21st to endNight
20%12%36%25%7%1
800
February1st to 10thNight
25%11%35%25%41
720
11th to 20thNight
22%12%37%24%5%
703
21st to endNight
26%10%34%27%4
592
March1st to 10thNight
26%10%32%26%6%
720
11th to 20thNight
29%10%32%23%7%
720
21st to endNight
26%8%30%26%8%1
792
April1st to 10thNight
28%12%29%26%5%
720
11th to 20thNight
28%12%29%24%7%1
711
21st to endNight
26%11%29%24%10%1
568
May1st to 10thNight
26%7%31%25%10%1
429
11th to 20thNight
22%8%31%30%8%1
354
21st to endNight
19%8%32%30%11%1
389
June1st to 10thNight
27%329%31%9%1
360
11th to 20thNight
21%429%32%14%
360
21st to endNight
18%5%28%35%14%1
360
July1st to 10thNight
14%5%27%36%17%
350
11th to 20thNight
10%326%43%16%2
348
21st to endNight
12%421%47%14%1
394
August1st to 10thNight
14%415%49%17%1
358
11th to 20thNight
14%422%35%24%2
538
21st to endNight
17%322%35%20%2
792
September1st to 10thNight
16%325%38%17%1
720
11th to 20thNight
18%5%19%35%19%3
720
21st to endNight
20%7%28%29%15%2
720
October1st to 10thNight
21%8%29%27%13%1
720
11th to 20thNight
27%9%28%27%10%
720
21st to endNight
29%10%30%26%5%
792
November1st to 10thNight
27%13%30%21%9%1
740
11th to 20thNight
26%13%31%21%9%1
760
21st to endNight
31%13%28%19%8%1
760
December1st to 10thNight
33%11%30%21%5%
760
11th to 20thNight
33%13%31%17%6%1
760
21st to endNight
34%13%31%18%4
836
Page generated at 2024-01-19 09:28:33. Version ac07

Copyright 2024 Attilla Danko


Candiac Clear Sky Chart |Charts Home