Saskatoon
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Saskatoon clear sky chart from 2005-11-05 to 2018-02-22.

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
41%
16314
12%
48922
8%
16285
46%
16285
22%
33626

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
33%
970
8%
2910
5%
970
36%
970
16%
2180
January16th to endNight
27%
1040
13%
3050
6%
1040
34%
1040
15%
2289
February1st to 15thNight
38%
844
12%
2570
9%
844
42%
844
18%
1861
February16th to endNight
45%
660
13%
2127
10%
660
50%
660
20%
1481
March1st to 15thNight
40%
720
15%
2112
10%
720
45%
720
21%
1493
March16th to endNight
38%
695
13%
2039
10%
695
42%
695
19%
1475
April1st to 15thNight
40%
539
15%
1795
10%
539
46%
539
24%
1133
April16th to endNight
39%
540
14%
1508
10%
540
42%
540
21%
1073
May1st to 15thNight
47%
539
12%
1439
7%
539
50%
539
29%
954
May16th to endNight
46%
454
5%
1348
4%
453
48%
453
26%
899
June1st to 15thNight
45%
360
0%
1080
0%
360
45%
360
21%
740
June16th to endNight
51%
360
0%
1080
0%
360
51%
360
26%
701
July1st to 15thNight
61%
340
0%
1117
0%
340
61%
340
34%
626
July16th to endNight
63%
417
8%
1277
6%
392
66%
392
40%
662
August1st to 15thNight
67%
539
12%
1432
7%
536
70%
536
44%
823
August16th to endNight
60%
573
21%
1726
16%
573
65%
573
39%
942
September1st to 15thNight
55%
540
16%
1800
16%
540
58%
540
31%
1042
September16th to endNight
52%
615
25%
1965
20%
615
60%
615
38%
1072
October1st to 15thNight
44%
720
18%
2160
11%
720
50%
720
26%
1402
October16th to endNight
39%
909
17%
2481
9%
909
44%
909
24%
1721
November1st to 15thNight
32%
950
14%
2660
7%
950
37%
950
18%
1970
November16th to endNight
30%
975
11%
2824
5%
975
36%
975
16%
2115
December1st to 15thNight
32%
975
6%
3094
4%
975
34%
975
12%
2424
December16th to endNight
35%
1040
11%
3328
6%
1040
41%
1040
13%
2548

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
12%8%47%6%35%5%5%7%33%
49364
Night
9%9%48%6%35%5%5%7%34%
49072
Cloud CoverDay
13%8%36%5%35%5%5%7%34%
49365
Night
10%8%47%6%35%5%5%7%35%
49074
TransparencyDay
48%5%17%21%6%
49016
Night
47%5%16%22%7%
48924
SeeingDay
15%6%23%29%19%5%
6616
Night
13%425%36%16%2
16329

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 15thDay
9%12%7%10%7%46%5%6%7%20%
1355
16th to endDay
7%10%5%11%8%47%6%5%6%25%
1524
February1st to 15thDay
7%12%6%9%8%5%6%7%6%6%22%
1632
16th to endDay
8%11%7%11%10%5%7%6%5%6%20%
1493
March1st to 15thDay
8%14%6%9%8%46%5%46%24%
1845
16th to endDay
10%14%5%8%7%35%45%7%26%
2184
April1st to 15thDay
11%11%5%6%5%36%5%6%6%31%
2150
16th to endDay
16%10%47%5%34436%32%
2451
May1st to 15thDay
13%6%26%5%36%5%6%6%38%
2511
16th to endDay
17%6%36%6%35%5%6%7%31%
2763
June1st to 15thDay
17%7%36%5%45%5%6%8%30%
2880
16th to endDay
16%7%37%6%35%5%6%8%29%
2880
July1st to 15thDay
9%4244345%6%9%43%
2773
16th to endDay
7%324435%5%6%9%45%
2804
August1st to 15thDay
11%5%25%5%346%6%9%40%
2520
16th to endDay
10%5%1342445%9%48%
2476
September1st to 15thDay
11%5%15%42336%7%47%
2160
16th to endDay
11%41432435%8%48%
1995
October1st to 15thDay
17%9%25%423447%37%
1800
16th to endDay
13%11%46%43445%7%33%
1731
November1st to 15thDay
14%14%49%5%24345%31%
1528
16th to endDay
10%13%6%10%7%5%6%5%36%24%
1465
December1st to 15thDay
9%13%6%11%9%6%6%45%8%17%
1196
16th to endDay
6%14%7%13%9%48%6%5%6%17%
1248
January1st to 15thNight
8%11%49%9%47%6%6%7%23%
2910
16th to endNight
7%10%5%10%9%46%5%5%7%26%
3050
February1st to 15thNight
6%9%5%12%8%37%5%5%7%28%
2560
16th to endNight
5%10%6%9%7%36%5%6%7%29%
2127
March1st to 15thNight
9%8%49%6%35%5%5%6%32%
2112
16th to endNight
10%11%49%6%3445%7%30%
2036
April1st to 15thNight
9%8%36%6%3435%7%39%
1795
16th to endNight
14%11%25%6%46%346%33%
1508
May1st to 15thNight
13%5%26%435%5%5%7%40%
1439
16th to endNight
14%6%24435%5%5%7%38%
1348
June1st to 15thNight
15%6%26%6%35%5%7%6%33%
1080
16th to endNight
14%6%26%435%5%6%8%38%
1080
July1st to 15thNight
6%325%435%5%7%9%46%
1185
16th to endNight
6%2133335%5%8%55%
1364
August1st to 15thNight
5%3133246%6%9%53%
1440
16th to endNight
8%32332345%9%53%
1726
September1st to 15thNight
12%415%43345%7%47%
1800
16th to endNight
9%413323348%54%
1965
October1st to 15thNight
13%8%35%42445%7%40%
2160
16th to endNight
10%10%37%5%34447%37%
2481
November1st to 15thNight
13%13%5%7%6%35%445%29%
2660
16th to endNight
8%13%5%9%7%45%448%27%
2824
December1st to 15thNight
9%13%6%10%8%45%5%6%6%21%
3094
16th to endNight
5%10%6%12%9%5%8%7%6%7%20%
3328

Percentage Cloud Cover SW (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
8%13%7%11%7%45%6%6%8%20%
1355
16th to endDay
7%10%6%10%9%47%6%5%6%25%
1524
February1st to 15thDay
7%12%6%11%8%47%7%6%6%22%
1632
16th to endDay
7%11%7%12%9%5%7%6%46%20%
1493
March1st to 15thDay
14%14%5%8%7%36%436%25%
1845
16th to endDay
15%11%47%6%35%446%28%
2185
April1st to 15thDay
10%11%46%6%35%5%5%7%34%
2150
16th to endDay
15%11%46%5%33336%35%
2451
May1st to 15thDay
16%6%2443445%6%40%
2511
16th to endDay
20%5%25%5%3445%7%35%
2763
June1st to 15thDay
16%7%36%5%35%46%7%33%
2880
16th to endDay
15%6%36%6%35%5%5%7%34%
2880
July1st to 15thDay
9%414435%5%7%9%43%
2773
16th to endDay
8%324435%5%7%9%46%
2804
August1st to 15thDay
22%5%2342445%8%37%
2520
16th to endDay
20%41331345%7%43%
2476
September1st to 15thDay
11%415%42345%9%46%
2160
16th to endDay
11%414424448%49%
1995
October1st to 15thDay
17%8%26%42335%7%37%
1800
16th to endDay
13%12%36%5%3446%7%32%
1731
November1st to 15thDay
14%13%5%8%5%23345%32%
1528
16th to endDay
10%12%7%10%8%5%5%445%25%
1465
December1st to 15thDay
9%13%6%11%9%6%7%5%5%6%18%
1196
16th to endDay
6%14%7%13%9%37%7%6%5%17%
1248
January1st to 15thNight
8%11%5%10%8%47%7%6%8%23%
2910
16th to endNight
7%11%5%11%9%45%5%5%7%26%
3050
February1st to 15thNight
7%9%5%11%8%46%5%6%7%27%
2560
16th to endNight
6%10%6%9%8%35%5%6%8%29%
2127
March1st to 15thNight
15%6%48%5%35%445%34%
2112
16th to endNight
16%9%47%5%345%5%6%32%
2039
April1st to 15thNight
9%7%35%7%3445%7%41%
1795
16th to endNight
14%10%35%6%45%446%35%
1508
May1st to 15thNight
14%5%25%5%25%5%6%6%40%
1439
16th to endNight
15%6%34425%5%6%7%38%
1347
June1st to 15thNight
15%5%36%6%35%6%6%7%33%
1080
16th to endNight
13%6%35%425%47%9%36%
1080
July1st to 15thNight
6%3244345%7%9%46%
1185
16th to endNight
6%3133235%5%8%56%
1364
August1st to 15thNight
8%3123245%6%8%52%
1440
16th to endNight
12%32332335%8%50%
1726
September1st to 15thNight
12%425%42345%7%47%
1800
16th to endNight
9%32332335%7%54%
1965
October1st to 15thNight
13%7%35%5%2445%7%39%
2160
16th to endNight
11%10%37%5%34447%37%
2481
November1st to 15thNight
13%12%5%6%5%34445%34%
2660
16th to endNight
9%11%5%8%6%45%446%32%
2824
December1st to 15thNight
10%12%6%11%8%5%6%5%6%5%21%
3094
16th to endNight
6%10%5%12%9%5%7%8%5%7%21%
3328

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
60%5%13%15%5%
1355
16th to endDay
56%6%13%16%6%
1524
February1st to 15thDay
59%6%15%16%3
1632
16th to endDay
63%411%14%6%
1493
March1st to 15thDay
59%416%14%3
1845
16th to endDay
55%6%15%18%4
2185
April1st to 15thDay
50%6%14%19%8%
2150
16th to endDay
54%314%18%8%
2451
May1st to 15thDay
43%412%28%8%1
2511
16th to endDay
49%5%14%17%12%
2767
June1st to 15thDay
51%315%21%6%
2880
16th to endDay
50%6%17%20%4
2880
July1st to 15thDay
34%6%22%30%6%
2612
16th to endDay
33%6%25%29%4
2628
August1st to 15thDay
38%6%25%23%6%
2504
16th to endDay
32%421%33%7%
2476
September1st to 15thDay
35%318%27%11%1
2160
16th to endDay
33%320%29%11%1
1995
October1st to 15thDay
46%418%25%5%
1800
16th to endDay
49%319%22%3
1731
November1st to 15thDay
55%318%16%6%
1528
16th to endDay
62%5%15%14%2
1465
December1st to 15thDay
65%5%15%10%2
1196
16th to endDay
63%6%13%10%5%
1248
January1st to 15thNight
57%5%17%16%4
2910
16th to endNight
56%6%14%16%6%
3050
February1st to 15thNight
53%414%21%5%
2571
16th to endNight
51%417%19%7%
2127
March1st to 15thNight
49%418%21%5%
2112
16th to endNight
51%5%15%19%6%
2039
April1st to 15thNight
42%414%23%13%1
1795
16th to endNight
50%411%18%11%3
1508
May1st to 15thNight
41%49%30%12%1
1440
16th to endNight
43%5%14%19%15%2
1348
June1st to 15thNight
47%5%12%23%10%
1080
16th to endNight
41%5%21%22%8%
1080
July1st to 15thNight
29%6%23%30%9%
1117
16th to endNight
25%427%33%7%
1277
August1st to 15thNight
25%6%28%29%9%
1432
16th to endNight
27%415%36%14%
1726
September1st to 15thNight
35%314%28%13%4
1800
16th to endNight
29%313%35%15%1
1965
October1st to 15thNight
43%316%27%8%
2160
16th to endNight
46%417%24%5%
2481
November1st to 15thNight
55%414%18%5%
2660
16th to endNight
55%5%19%15%3
2824
December1st to 15thNight
61%6%16%12%2
3094
16th to endNight
59%6%12%14%6%
3328

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
12%221%31%27%5%
90
16th to endDay
15%6%29%27%17%3
112
February1st to 15thDay
15%231%38%11%
135
16th to endDay
15%324%37%17%4
100
March1st to 15thDay
22%8%37%21%8%1
135
16th to endDay
18%11%30%28%10%1
288
April1st to 15thDay
13%14%33%25%9%2
269
16th to endDay
23%8%22%25%18%2
381
May1st to 15thDay
17%7%21%34%16%3
468
16th to endDay
15%7%20%26%20%8%
517
June1st to 15thDay
16%7%26%30%15%3
495
16th to endDay
19%421%31%18%5%
495
July1st to 15thDay
11%218%30%26%9%
475
16th to endDay
7%426%27%26%8%
515
August1st to 15thDay
10%314%27%30%13%
493
16th to endDay
10%323%30%25%5%
364
September1st to 15thDay
17%6%25%30%15%3
315
16th to endDay
13%6%20%33%19%7%
228
October1st to 15thDay
23%423%28%14%5%
135
16th to endDay
20%433%27%11%2
144
November1st to 15thDay
14%28%37%14%4
135
16th to endDay
18%10%22%27%15%5%
135
December1st to 15thDay
8%321%41%15%9%
96
16th to endDay
9%25%42%14%8%
96
January1st to 15thNight
14%5%30%35%13%2
975
16th to endNight
12%7%35%32%10%1
1040
February1st to 15thNight
10%325%38%19%2
852
16th to endNight
9%322%37%22%4
660
March1st to 15thNight
12%5%26%37%15%2
720
16th to endNight
14%7%27%35%13%2
695
April1st to 15thNight
10%8%29%36%13%2
539
16th to endNight
21%6%22%32%14%1
540
May1st to 15thNight
14%5%24%39%15%
540
16th to endNight
18%325%32%16%3
455
June1st to 15thNight
17%5%21%34%18%2
360
16th to endNight
17%417%34%23%2
360
July1st to 15thNight
7%221%40%25%2
340
16th to endNight
7%320%42%23%1
417
August1st to 15thNight
8%216%35%33%3
539
16th to endNight
10%221%40%23%1
573
September1st to 15thNight
14%318%37%23%2
540
16th to endNight
11%426%39%16%1
615
October1st to 15thNight
18%424%35%16%1
720
16th to endNight
16%426%39%11%
909
November1st to 15thNight
18%6%28%33%11%1
950
16th to endNight
15%6%30%34%10%2
975
December1st to 15thNight
14%6%24%35%17%2
975
16th to endNight
8%328%34%20%4
1040
Page generated at 2018-02-23 10:21:39. Version ac04

Copyright 2018 A. Danko


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