Parc national d'Oka
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Parc national d'Oka clear sky chart from 2005-11-05 to 2018-03-11.

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
33%
15338
14%
49116
9%
15308
39%
15308
17%
34821

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
21%
780
9%
2716
5%
776
27%
776
10%
2122
January16th to endNight
23%
832
10%
2912
6%
832
29%
832
12%
2167
February1st to 15thNight
23%
763
10%
2496
6%
761
29%
761
11%
1925
February16th to endNight
26%
683
15%
2054
7%
683
36%
683
16%
1513
March1st to 15thNight
24%
764
13%
2291
8%
764
30%
764
14%
1741
March16th to endNight
35%
768
20%
1992
11%
768
42%
768
25%
1398
April1st to 15thNight
32%
718
17%
1796
6%
718
37%
718
21%
1333
April16th to endNight
32%
633
17%
1713
6%
633
39%
633
23%
1206
May1st to 15thNight
33%
384
17%
1464
14%
384
43%
384
17%
973
May16th to endNight
40%
374
13%
1497
14%
374
48%
374
17%
973
June1st to 15thNight
37%
360
9%
1440
9%
360
45%
360
15%
1000
June16th to endNight
46%
360
9%
1440
12%
360
51%
360
20%
897
July1st to 15thNight
52%
340
14%
1360
20%
340
59%
340
26%
774
July16th to endNight
56%
376
13%
1418
17%
354
59%
354
25%
817
August1st to 15thNight
56%
368
15%
1439
17%
366
59%
366
23%
841
August16th to endNight
56%
758
20%
1904
11%
758
59%
758
37%
1224
September1st to 15thNight
52%
720
15%
1800
9%
720
53%
720
30%
1244
September16th to endNight
52%
717
22%
1962
16%
717
56%
717
32%
1234
October1st to 15thNight
37%
720
19%
2130
11%
720
46%
720
22%
1450
October16th to endNight
28%
768
12%
2453
9%
768
34%
768
15%
1787
November1st to 15thNight
28%
760
16%
2472
11%
760
37%
760
17%
1752
November16th to endNight
22%
780
12%
2725
8%
780
29%
780
11%
2028
December1st to 15thNight
19%
780
9%
2730
4%
780
25%
780
9%
2130
December16th to endNight
15%
832
11%
2912
5%
832
23%
832
9%
2292

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%8%36%5%3445%6%33%
49518
Night
18%9%36%5%34446%32%
49285
Cloud CoverDay
17%8%36%5%3445%7%33%
49527
Night
18%9%36%5%34446%32%
49291
TransparencyDay
49%412%21%10%1
49205
Night
52%410%20%10%1
49116
SeeingDay
21%6%24%26%15%5%
6069
Night
23%7%27%29%11%
15340

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
21%14%5%8%6%3443422%
1552
16th to endDay
13%13%5%9%7%35%35%5%27%
1664
February1st to 15thDay
14%12%5%10%8%35%5%46%23%
1694
16th to endDay
18%12%5%8%6%3444428%
1705
March1st to 15thDay
18%12%5%7%7%35%44327%
1896
16th to endDay
18%8%36%433336%37%
2229
April1st to 15thDay
21%9%35%5%23445%32%
2152
16th to endDay
19%7%35%433445%37%
2247
May1st to 15thDay
20%6%36%5%44446%33%
2497
16th to endDay
18%7%25%5%3445%7%34%
2618
June1st to 15thDay
21%7%25%5%3445%7%31%
2520
16th to endDay
17%6%25%5%36%5%5%8%31%
2520
July1st to 15thDay
11%5%25%5%36%5%6%9%39%
2520
16th to endDay
11%5%245%46%5%7%11%35%
2654
August1st to 15thDay
12%6%26%6%35%5%6%8%35%
2500
16th to endDay
9%3144345%5%9%46%
2292
September1st to 15thDay
15%5%25%4245%5%7%41%
2160
16th to endDay
14%424423446%49%
1998
October1st to 15thDay
20%7%35%5%34445%35%
1827
16th to endDay
23%9%37%5%3345%6%27%
1770
November1st to 15thDay
16%8%46%5%345%6%7%31%
1716
16th to endDay
22%9%37%6%34446%27%
1563
December1st to 15thDay
24%12%49%5%245%5%6%19%
1560
16th to endDay
24%13%5%7%6%3434321%
1664
January1st to 15thNight
18%15%6%8%6%34445%21%
2716
16th to endNight
13%14%5%9%7%45%44426%
2912
February1st to 15thNight
13%12%5%9%8%35%5%5%6%22%
2494
16th to endNight
17%11%5%8%5%345%4430%
2054
March1st to 15thNight
20%11%47%6%35%44427%
2278
16th to endNight
16%10%36%32334440%
1992
April1st to 15thNight
25%7%35%5%24336%32%
1796
16th to endNight
21%7%25%5%24346%36%
1713
May1st to 15thNight
22%7%45%5%33345%34%
1464
16th to endNight
20%6%25%425%347%36%
1495
June1st to 15thNight
23%7%25%4345%5%8%29%
1440
16th to endNight
15%5%25%5%35%5%7%8%36%
1440
July1st to 15thNight
10%4146%35%5%5%10%42%
1440
16th to endNight
10%434425%5%7%9%42%
1514
August1st to 15thNight
10%5%35%4245%5%10%40%
1449
16th to endNight
11%42443336%7%48%
1904
September1st to 15thNight
15%5%36%5%33447%40%
1800
16th to endNight
16%423413346%48%
1962
October1st to 15thNight
17%6%35%434446%38%
2130
16th to endNight
23%8%37%5%34445%30%
2453
November1st to 15thNight
21%7%36%5%34445%33%
2472
16th to endNight
22%11%47%5%2444427%
2725
December1st to 15thNight
22%15%47%5%24445%23%
2730
16th to endNight
23%16%5%7%6%2334423%
2912

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
21%14%5%8%7%335%4422%
1552
16th to endDay
13%13%5%7%7%35%46%6%25%
1664
February1st to 15thDay
14%13%5%9%7%36%5%5%5%23%
1694
16th to endDay
17%12%5%7%5%44445%27%
1705
March1st to 15thDay
18%11%49%7%345%3427%
1906
16th to endDay
18%6%36%424347%37%
2228
April1st to 15thDay
21%7%45%6%33445%32%
2152
16th to endDay
18%7%26%5%33445%37%
2247
May1st to 15thDay
19%6%25%6%35%45%6%33%
2497
16th to endDay
18%6%25%5%3446%7%35%
2618
June1st to 15thDay
21%7%25%5%3445%7%32%
2520
16th to endDay
16%6%25%6%36%5%5%8%32%
2520
July1st to 15thDay
10%5%25%5%36%5%6%8%40%
2520
16th to endDay
11%425%5%35%6%7%9%37%
2654
August1st to 15thDay
11%6%25%6%446%6%9%35%
2500
16th to endDay
9%3134245%6%9%47%
2292
September1st to 15thDay
15%5%2443445%7%42%
2160
16th to endDay
13%415%414447%49%
1998
October1st to 15thDay
19%6%26%5%3445%5%35%
1827
16th to endDay
22%9%36%5%34447%27%
1770
November1st to 15thDay
17%9%35%5%345%6%7%31%
1716
16th to endDay
21%9%37%7%33446%26%
1563
December1st to 15thDay
24%12%48%5%345%5%5%18%
1560
16th to endDay
25%13%5%8%43344420%
1664
January1st to 15thNight
18%15%5%9%6%44445%21%
2716
16th to endNight
14%13%6%8%6%45%445%26%
2912
February1st to 15thNight
13%13%6%10%7%46%5%46%21%
2487
16th to endNight
16%11%5%8%5%35%445%29%
2054
March1st to 15thNight
21%11%47%5%35%34426%
2291
16th to endNight
17%10%35%42333440%
1992
April1st to 15thNight
25%7%26%434346%32%
1796
16th to endNight
22%7%25%5%24345%36%
1713
May1st to 15thNight
22%6%36%5%23346%35%
1464
16th to endNight
19%5%35%435%347%35%
1495
June1st to 15thNight
23%7%35%4245%5%8%28%
1440
16th to endNight
15%6%25%4445%7%7%35%
1440
July1st to 15thNight
10%315%6%35%6%6%10%41%
1440
16th to endNight
10%5%245%3447%8%42%
1514
August1st to 15thNight
11%5%26%4245%6%9%40%
1449
16th to endNight
12%32443445%8%46%
1904
September1st to 15thNight
15%6%35%5%24447%41%
1800
16th to endNight
16%5%23323346%47%
1962
October1st to 15thNight
17%5%26%434446%37%
2130
16th to endNight
24%7%37%5%34345%29%
2453
November1st to 15thNight
21%7%36%5%2435%5%33%
2472
16th to endNight
22%10%48%6%2344427%
2725
December1st to 15thNight
23%14%47%5%24445%21%
2730
16th to endNight
23%16%5%7%5%23345%21%
2912

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
65%48%14%6%
1553
16th to endDay
57%412%16%7%
1664
February1st to 15thDay
61%311%18%3
1696
16th to endDay
58%311%16%8%1
1705
March1st to 15thDay
60%312%15%8%1
1906
16th to endDay
47%310%18%15%4
2229
April1st to 15thDay
53%36%21%12%2
2152
16th to endDay
48%29%20%14%3
2247
May1st to 15thDay
50%49%20%13%2
2497
16th to endDay
47%411%21%12%1
2622
June1st to 15thDay
51%5%10%20%10%
2520
16th to endDay
47%5%13%21%9%1
2520
July1st to 15thDay
38%6%15%27%12%
2371
16th to endDay
40%6%18%24%9%
2487
August1st to 15thDay
42%6%18%23%8%
2486
16th to endDay
31%5%18%31%12%
2292
September1st to 15thDay
39%414%27%12%
2160
16th to endDay
36%412%34%12%
1998
October1st to 15thDay
49%5%11%24%9%
1827
16th to endDay
56%414%17%7%
1770
November1st to 15thDay
49%5%15%20%8%
1716
16th to endDay
57%5%9%18%6%
1563
December1st to 15thDay
64%7%11%12%3
1560
16th to endDay
65%5%9%12%6%
1664
January1st to 15thNight
64%49%15%4
2716
16th to endNight
60%410%16%7%
2912
February1st to 15thNight
61%5%11%15%4
2496
16th to endNight
56%49%17%11%
2054
March1st to 15thNight
60%39%16%8%1
2291
16th to endNight
48%38%19%16%4
1992
April1st to 15thNight
54%36%19%15%1
1796
16th to endNight
48%37%19%16%4
1713
May1st to 15thNight
50%37%18%15%4
1464
16th to endNight
48%49%21%14%1
1497
June1st to 15thNight
52%5%10%20%9%
1440
16th to endNight
43%5%14%19%15%
1440
July1st to 15thNight
34%6%12%29%15%
1360
16th to endNight
36%6%17%25%13%
1418
August1st to 15thNight
37%6%19%24%11%
1439
16th to endNight
34%415%30%13%
1904
September1st to 15thNight
42%5%10%25%14%
1800
16th to endNight
37%410%31%14%
1962
October1st to 15thNight
46%5%9%26%11%
2130
16th to endNight
56%413%19%6%
2453
November1st to 15thNight
52%412%19%9%2
2472
16th to endNight
59%5%11%17%6%
2725
December1st to 15thNight
63%5%11%15%3
2730
16th to endNight
64%5%8%13%6%
2912

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
23%14%22%27%11%1
90
16th to endDay
29%10%33%18%6%2
96
February1st to 15thDay
33%9%34%21%1
131
16th to endDay
29%431%29%4
286
March1st to 15thDay
25%8%31%26%7%
312
16th to endDay
25%7%23%27%13%2
288
April1st to 15thDay
30%8%25%22%10%2
270
16th to endDay
21%7%27%24%15%4
270
May1st to 15thDay
26%6%25%21%14%5%
288
16th to endDay
20%6%31%19%15%5%
331
June1st to 15thDay
26%7%21%29%11%3
315
16th to endDay
19%322%35%16%2
315
July1st to 15thDay
11%5%23%31%20%7%
305
16th to endDay
13%314%36%24%6%
326
August1st to 15thDay
13%218%33%22%9%
313
16th to endDay
9%321%28%21%14%
332
September1st to 15thDay
16%5%18%23%21%14%
315
16th to endDay
15%6%20%19%26%11%
314
October1st to 15thDay
19%6%23%25%19%5%
315
16th to endDay
26%10%28%23%11%
298
November1st to 15thDay
24%8%25%26%13%1
280
16th to endDay
30%6%31%24%7%
93
December1st to 15thDay
27%5%31%26%7%1
90
16th to endDay
34%12%33%15%4
96
January1st to 15thNight
25%11%29%27%5%
780
16th to endNight
21%10%34%25%8%
832
February1st to 15thNight
20%8%34%28%7%
764
16th to endNight
23%7%33%29%7%
683
March1st to 15thNight
27%9%29%27%6%
764
16th to endNight
21%7%26%32%10%
768
April1st to 15thNight
27%7%25%33%5%
718
16th to endNight
25%8%27%26%11%
633
May1st to 15thNight
25%426%30%10%2
384
16th to endNight
20%426%37%10%
375
June1st to 15thNight
29%122%34%10%
360
16th to endNight
17%225%36%15%1
360
July1st to 15thNight
10%324%37%21%1
340
16th to endNight
13%220%44%17%1
376
August1st to 15thNight
14%215%42%24%1
368
16th to endNight
13%220%35%26%1
758
September1st to 15thNight
18%318%39%18%1
720
16th to endNight
19%419%28%25%2
717
October1st to 15thNight
20%5%27%30%14%
720
16th to endNight
28%7%28%27%7%
768
November1st to 15thNight
26%8%28%24%10%
760
16th to endNight
27%10%29%20%10%1
780
December1st to 15thNight
31%11%27%24%4
780
16th to endNight
32%9%30%22%4
832
Page generated at 2018-03-12 13:28:04. Version ac04

Copyright 2018 A. Danko


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