Cold Lake
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cold Lake clear sky chart from 2005-11-06 to 2024-02-25.

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
39%
23809
10%
81112
7%
23755
43%
23755
17%
56616

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
34%
935
7%
4702
5%
926
38%
926
8%
3696
January11th to 20thNight
33%
935
12%
4647
7%
929
38%
929
10%
3278
January21st to endNight
26%
1032
7%
5190
4%
1023
32%
1023
8%
3619
February1st to 10thNight
37%
832
11%
2690
8%
832
41%
832
15%
2002
February11th to 20thNight
37%
740
16%
2402
13%
740
43%
740
19%
1683
February21st to endNight
47%
610
14%
1982
12%
610
51%
610
17%
1411
March1st to 10thNight
39%
720
11%
2174
9%
720
42%
720
19%
1606
March11th to 20thNight
39%
720
15%
1980
9%
720
43%
720
23%
1420
March21st to endNight
41%
776
12%
2162
8%
776
44%
776
20%
1593
April1st to 10thNight
44%
540
15%
1708
10%
540
48%
540
22%
1128
April11th to 20thNight
37%
533
16%
1601
11%
533
43%
533
20%
1107
April21st to endNight
38%
540
12%
1517
9%
540
41%
540
22%
1067
May1st to 10thNight
43%
485
10%
1385
6%
485
46%
485
24%
922
May11th to 20thNight
50%
354
5%
1239
4%
354
52%
354
28%
735
May21st to endNight
46%
388
0%
1326
0%
388
46%
388
18%
908
June1st to 10thNight
45%
360
0%
1080
0%
360
45%
360
20%
753
June11th to 20thNight
41%
360
0%
1080
0%
360
41%
360
15%
812
June21st to endNight
58%
360
0%
1080
0%
360
58%
360
24%
716
July1st to 10thNight
56%
350
0%
1125
0%
350
56%
350
28%
685
July11th to 20thNight
56%
348
0%
1218
0%
348
56%
348
24%
748
July21st to endNight
60%
394
2%
1302
1%
372
62%
372
29%
742
August1st to 10thNight
63%
366
8%
1254
7%
364
65%
364
28%
738
August11th to 20thNight
57%
534
10%
1539
9%
534
60%
534
30%
963
August21st to endNight
53%
594
15%
1782
13%
594
56%
594
27%
1145
September1st to 10thNight
47%
540
13%
1718
10%
540
50%
540
26%
1089
September11th to 20thNight
50%
616
16%
1876
11%
616
56%
616
28%
1192
September21st to endNight
46%
720
19%
2007
12%
720
53%
720
31%
1243
October1st to 10thNight
39%
720
16%
2160
11%
720
44%
720
22%
1477
October11th to 20thNight
36%
720
15%
2200
7%
720
44%
720
21%
1500
October21st to endNight
30%
931
12%
2713
5%
931
36%
931
15%
2044
November1st to 10thNight
31%
925
12%
2590
9%
925
33%
925
13%
2084
November11th to 20thNight
30%
950
8%
2720
4%
950
34%
950
12%
2214
November21st to endNight
26%
950
8%
2940
2%
950
32%
950
13%
2246
December1st to 10thNight
33%
950
10%
3040
5%
950
38%
950
14%
2299
December11th to 20thNight
25%
950
8%
3715
2%
949
30%
949
8%
2893
December21st to endNight
34%
1031
7%
5268
7%
1026
39%
1026
11%
2858

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
10%8%48%7%46%5%6%8%33%
77550
Night
9%9%49%8%46%5%6%7%32%
81697
TransparencyDay
47%9%17%20%6%
77250
Night
49%8%15%19%8%1
81577
SeeingDay
13%8%28%30%16%4
14556
Night
13%6%29%35%15%2
23871

By Month

Percentage Cloud Cover NW (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
5%14%7%15%13%6%6%45%5%20%
2219
11th to 20thDay
5%8%49%8%5%9%10%8%11%23%
2199
21st to endDay
6%13%6%13%9%5%5%45%5%28%
2442
February1st to 10thDay
7%11%6%10%10%5%6%7%7%6%25%
1509
11th to 20thDay
6%10%5%11%9%5%7%6%7%8%26%
1665
21st to endDay
6%9%5%11%10%5%6%6%8%8%26%
1368
March1st to 10thDay
8%11%5%12%8%46%7%7%10%23%
1786
11th to 20thDay
8%11%6%8%7%445%6%8%33%
1979
21st to endDay
9%13%49%7%46%5%5%7%31%
2194
April1st to 10thDay
8%11%5%7%7%5%5%6%6%8%33%
2250
11th to 20thDay
13%9%37%7%5%6%5%6%7%31%
2310
21st to endDay
12%10%48%6%46%5%6%6%32%
2442
May1st to 10thDay
10%6%48%7%45%6%7%8%36%
2574
11th to 20thDay
9%5%27%6%46%5%6%7%43%
2654
21st to endDay
16%5%35%435%6%7%8%38%
2948
June1st to 10thDay
16%6%37%7%36%7%6%8%31%
2880
11th to 20thDay
20%8%47%6%46%5%7%7%25%
2880
21st to endDay
13%7%37%6%5%6%5%7%9%32%
2880
July1st to 10thDay
12%6%35%5%46%5%6%8%40%
2798
11th to 20thDay
11%6%25%446%7%7%11%38%
2700
21st to endDay
9%5%35%5%46%6%7%8%42%
2938
August1st to 10thDay
11%5%35%6%35%6%7%9%41%
2678
11th to 20thDay
10%425%5%35%5%7%9%44%
2361
21st to endDay
11%6%26%6%45%6%7%9%40%
2574
September1st to 10thDay
13%7%26%5%445%5%8%41%
2242
11th to 20thDay
17%7%25%5%2445%8%41%
2082
21st to endDay
10%6%36%7%35%5%7%8%41%
1952
October1st to 10thDay
13%10%36%7%35%46%7%35%
1800
11th to 20thDay
11%8%46%6%45%5%6%7%37%
1758
21st to endDay
11%13%5%8%6%45%5%5%7%30%
1625
November1st to 10thDay
12%14%5%11%8%46%45%7%24%
1488
11th to 20thDay
9%13%5%12%9%46%6%6%7%22%
1459
21st to endDay
6%10%5%13%8%5%7%5%5%7%28%
1238
December1st to 10thDay
6%9%5%13%11%47%6%6%9%24%
1140
11th to 20thDay
8%12%5%12%9%46%5%5%8%25%
1439
21st to endDay
48%38%6%46%6%7%7%40%
2099
January1st to 10thNight
5%11%6%16%14%6%6%5%5%6%19%
4726
11th to 20thNight
48%49%9%7%11%8%7%9%23%
4699
21st to endNight
6%11%7%11%9%46%5%6%7%28%
5214
February1st to 10thNight
7%11%5%10%10%5%6%6%5%7%26%
2690
11th to 20thNight
6%11%5%9%9%5%5%5%6%8%32%
2402
21st to endNight
49%6%9%8%6%7%8%7%7%30%
1982
March1st to 10thNight
7%10%5%12%8%5%6%6%5%8%28%
2174
11th to 20thNight
9%11%5%8%6%45%5%5%7%35%
1980
21st to endNight
8%13%5%8%7%46%6%6%8%29%
2162
April1st to 10thNight
8%8%48%6%46%5%7%9%36%
1708
11th to 20thNight
10%8%38%8%46%5%7%8%33%
1601
21st to endNight
13%10%5%7%7%345%5%7%36%
1517
May1st to 10thNight
10%9%36%7%345%6%8%37%
1385
11th to 20thNight
11%435%5%35%5%7%7%46%
1239
21st to endNight
17%7%46%6%36%5%7%7%32%
1326
June1st to 10thNight
17%7%46%6%35%6%6%8%33%
1080
11th to 20thNight
17%9%37%6%47%5%6%10%25%
1080
21st to endNight
13%426%6%36%6%6%9%39%
1080
July1st to 10thNight
11%5%25%5%25%5%6%9%46%
1159
11th to 20thNight
11%5%25%5%36%5%7%8%43%
1260
21st to endNight
8%425%5%35%5%7%11%45%
1379
August1st to 10thNight
10%334435%6%8%9%45%
1261
11th to 20thNight
9%435%5%346%6%9%47%
1539
21st to endNight
11%5%26%6%35%6%6%7%43%
1782
September1st to 10thNight
15%6%25%4345%6%7%43%
1718
11th to 20thNight
12%6%25%5%3445%8%46%
1876
21st to endNight
8%5%34435%6%7%9%46%
2007
October1st to 10thNight
13%7%37%6%45%5%5%6%38%
2160
11th to 20thNight
10%10%46%6%35%5%6%7%37%
2200
21st to endNight
12%12%49%6%45%5%5%7%31%
2713
November1st to 10thNight
13%15%6%8%8%35%5%5%6%25%
2590
11th to 20thNight
10%12%6%13%8%45%5%6%7%24%
2720
21st to endNight
6%11%7%12%8%45%5%6%7%27%
2940
December1st to 10thNight
8%11%5%10%8%6%6%6%7%7%26%
3040
11th to 20thNight
8%13%5%13%10%5%6%6%6%8%21%
3753
21st to endNight
47%48%7%45%6%6%6%43%
5555

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
66%6%12%12%4
2219
11th to 20thDay
53%9%15%17%6%1
2220
21st to endDay
57%8%16%13%6%
2442
February1st to 10thDay
56%9%13%13%10%
1509
11th to 20thDay
53%7%15%17%7%1
1674
21st to endDay
53%6%16%17%7%
1368
March1st to 10thDay
55%7%18%16%4
1786
11th to 20thDay
50%7%14%22%7%
1980
21st to endDay
51%9%16%18%6%
2194
April1st to 10thDay
48%8%16%19%9%
2250
11th to 20thDay
52%7%13%19%8%1
2310
21st to endDay
50%7%13%21%8%1
2442
May1st to 10thDay
42%8%14%22%13%1
2574
11th to 20thDay
38%7%14%26%14%1
2658
21st to endDay
42%8%14%24%11%1
2949
June1st to 10thDay
47%10%16%17%9%1
2880
11th to 20thDay
55%9%14%17%41
2880
21st to endDay
46%10%16%22%5%
2880
July1st to 10thDay
39%10%19%25%5%1
2723
11th to 20thDay
38%12%26%22%2
2619
21st to endDay
36%13%24%25%3
2775
August1st to 10thDay
37%12%23%26%2
2660
11th to 20thDay
35%10%30%21%5%
2361
21st to endDay
38%10%23%26%2
2574
September1st to 10thDay
41%9%18%24%7%1
2242
11th to 20thDay
43%7%20%26%4
2082
21st to endDay
39%9%19%23%9%1
1952
October1st to 10thDay
48%8%16%22%5%
1800
11th to 20thDay
46%7%14%26%6%
1758
21st to endDay
54%8%16%16%5%
1625
November1st to 10thDay
62%9%12%13%4
1488
11th to 20thDay
63%8%14%12%3
1459
21st to endDay
58%8%13%16%41
1238
December1st to 10thDay
60%7%11%16%5%1
1140
11th to 20thDay
60%8%13%15%4
1440
21st to endDay
40%6%16%26%11%1
2099
January1st to 10thNight
64%7%11%12%6%
4726
11th to 20thNight
55%7%16%16%5%1
4740
21st to endNight
55%9%17%14%5%
5214
February1st to 10thNight
55%8%12%17%8%
2690
11th to 20thNight
50%6%13%21%9%
2403
21st to endNight
50%8%15%18%10%
1982
March1st to 10thNight
53%7%16%18%6%
2174
11th to 20thNight
48%7%14%22%8%
1980
21st to endNight
51%8%14%20%7%
2162
April1st to 10thNight
44%7%15%21%13%
1708
11th to 20thNight
46%8%11%19%13%3
1601
21st to endNight
47%7%12%21%11%2
1517
May1st to 10thNight
43%7%10%23%16%2
1385
11th to 20thNight
35%8%10%27%18%2
1239
21st to endNight
47%8%11%21%11%2
1326
June1st to 10thNight
47%8%13%18%12%2
1080
11th to 20thNight
52%11%14%15%7%1
1080
21st to endNight
41%9%18%22%9%1
1080
July1st to 10thNight
34%10%21%28%6%1
1125
11th to 20thNight
36%11%23%27%4
1218
21st to endNight
31%9%29%28%3
1302
August1st to 10thNight
33%9%23%33%3
1254
11th to 20thNight
34%9%25%24%7%
1539
21st to endNight
39%8%18%30%5%
1782
September1st to 10thNight
40%6%20%23%8%3
1718
11th to 20thNight
38%7%20%26%9%
1876
21st to endNight
33%8%17%30%10%1
2007
October1st to 10thNight
47%6%15%23%8%
2160
11th to 20thNight
46%7%16%25%7%
2200
21st to endNight
55%7%14%17%7%
2713
November1st to 10thNight
61%8%10%16%5%
2590
11th to 20thNight
62%9%14%11%4
2720
21st to endNight
57%8%16%15%4
2940
December1st to 10thNight
57%7%13%16%6%1
3040
11th to 20thNight
62%8%14%11%5%
3751
21st to endNight
39%7%15%25%13%2
5555

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
11%427%36%17%6%
180
11th to 20thDay
14%8%25%36%12%6%
180
21st to endDay
9%12%31%37%8%4
198
February1st to 10thDay
10%7%39%33%10%2
200
11th to 20thDay
8%9%31%30%19%5%
270
21st to endDay
8%6%30%35%17%4
210
March1st to 10thDay
11%7%33%36%12%1
334
11th to 20thDay
10%11%37%28%10%3
420
21st to endDay
16%6%35%31%11%2
462
April1st to 10thDay
10%11%37%31%10%2
420
11th to 20thDay
18%8%31%26%13%3
412
21st to endDay
13%11%34%31%10%1
522
May1st to 10thDay
10%10%28%29%18%5%
603
11th to 20thDay
9%7%26%32%19%7%
625
21st to endDay
17%6%23%30%19%5%
679
June1st to 10thDay
17%9%29%30%12%3
630
11th to 20thDay
19%10%27%24%16%4
630
21st to endDay
12%6%22%31%21%8%
630
July1st to 10thDay
13%5%23%32%24%4
621
11th to 20thDay
11%5%24%34%22%4
618
21st to endDay
8%5%27%29%23%8%
684
August1st to 10thDay
13%6%18%29%27%7%
626
11th to 20thDay
10%6%24%35%20%4
499
21st to endDay
11%8%23%30%21%6%
495
September1st to 10thDay
15%12%31%26%14%2
450
11th to 20thDay
20%7%25%30%15%2
450
21st to endDay
11%13%31%28%13%4
422
October1st to 10thDay
13%10%27%32%15%3
270
11th to 20thDay
17%9%36%27%11%
270
21st to endDay
19%14%27%27%11%2
297
November1st to 10thDay
18%11%23%32%14%1
270
11th to 20thDay
15%10%44%25%42
241
21st to endDay
9%11%36%32%6%6%
180
December1st to 10thDay
7%7%34%33%17%3
180
11th to 20thDay
10%8%41%31%9%1
180
21st to endDay
7%6%29%34%19%6%
198
January1st to 10thNight
12%6%29%37%14%2
950
11th to 20thNight
11%5%31%39%12%2
950
21st to endNight
14%9%34%32%9%2
1045
February1st to 10thNight
11%7%26%39%16%2
832
11th to 20thNight
11%433%35%15%2
744
21st to endNight
7%424%43%20%3
610
March1st to 10thNight
10%431%40%13%2
720
11th to 20thNight
13%6%31%37%12%2
720
21st to endNight
14%8%25%35%16%2
776
April1st to 10thNight
9%5%31%39%15%1
540
11th to 20thNight
13%8%31%33%14%2
533
21st to endNight
17%6%29%33%13%1
540
May1st to 10thNight
14%9%25%33%17%1
485
11th to 20thNight
12%428%38%16%3
354
21st to endNight
16%422%35%20%3
389
June1st to 10thNight
18%6%22%34%19%1
360
11th to 20thNight
19%7%22%30%20%2
360
21st to endNight
14%219%34%28%4
360
July1st to 10thNight
11%321%37%27%1
350
11th to 20thNight
12%220%41%23%1
348
21st to endNight
9%320%40%22%6%
394
August1st to 10thNight
11%117%37%27%6%
366
11th to 20thNight
10%320%39%27%2
534
21st to endNight
11%423%39%22%2
594
September1st to 10thNight
19%325%31%20%1
540
11th to 20thNight
13%6%25%38%18%1
616
21st to endNight
10%6%31%36%15%1
720
October1st to 10thNight
16%6%30%35%11%2
720
11th to 20thNight
15%6%32%32%14%2
720
21st to endNight
17%11%32%29%10%1
931
November1st to 10thNight
18%7%31%32%10%2
925
11th to 20thNight
16%7%32%32%11%3
950
21st to endNight
12%6%40%32%8%1
950
December1st to 10thNight
13%6%33%30%15%3
950
11th to 20thNight
12%7%33%36%9%2
950
21st to endNight
9%429%37%18%3
1045
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