Lake St. Peter Provincial Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lake St. Peter Provincial Park clear sky chart from 2005-11-05 to 2017-09-19.

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
26%
14679
13%
46821
7%
14648
33%
14648
15%
33777

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
11%
720
6%
2506
2%
716
16%
716
5%
2079
January16th to endNight
16%
768
11%
2565
4%
768
25%
768
9%
2007
February1st to 15thNight
13%
703
9%
2287
3%
701
20%
701
9%
1809
February16th to endNight
17%
631
14%
2012
5%
631
28%
631
12%
1482
March1st to 15thNight
15%
720
13%
2022
5%
720
23%
720
14%
1530
March16th to endNight
27%
768
20%
2091
9%
768
36%
768
22%
1413
April1st to 15thNight
19%
718
15%
1796
4%
718
25%
718
18%
1347
April16th to endNight
29%
594
18%
1674
9%
594
36%
594
21%
1180
May1st to 15thNight
32%
399
17%
1479
13%
399
42%
399
18%
951
May16th to endNight
33%
375
14%
1497
10%
374
45%
374
21%
905
June1st to 15thNight
31%
360
9%
1440
7%
360
42%
360
17%
942
June16th to endNight
42%
360
10%
1362
10%
360
49%
360
19%
863
July1st to 15thNight
43%
340
15%
1360
18%
340
51%
340
26%
757
July16th to endNight
45%
376
14%
1418
13%
354
54%
354
25%
804
August1st to 15thNight
49%
534
15%
1605
9%
532
54%
532
30%
984
August16th to endNight
49%
648
19%
1794
9%
648
54%
648
35%
1095
September1st to 15thNight
41%
720
16%
1800
7%
720
45%
720
30%
1200
September16th to endNight
43%
673
21%
1863
13%
673
47%
673
27%
1236
October1st to 15thNight
27%
660
16%
1980
9%
660
36%
660
18%
1408
October16th to endNight
19%
704
10%
2137
4%
704
26%
704
11%
1691
November1st to 15thNight
25%
700
16%
2405
12%
700
33%
700
13%
1732
November16th to endNight
18%
720
10%
2520
7%
720
23%
720
9%
2022
December1st to 15thNight
12%
720
6%
2520
2%
720
17%
720
6%
2110
December16th to endNight
9%
768
8%
2688
3%
768
16%
768
5%
2230

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%11%47%6%34446%29%
47971
Night
16%10%47%6%34446%30%
46991
Cloud CoverDay
17%11%47%6%34446%29%
47981
Night
15%11%47%6%34446%31%
46996
TransparencyDay
55%49%18%9%1
47659
Night
54%5%10%19%9%
46821
SeeingDay
24%13%30%19%8%3
5411
Night
22%14%31%22%8%
14680

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
18%16%8%11%6%2334420%
1432
16th to endDay
13%15%6%12%8%45%345%20%
1659
February1st to 15thDay
10%17%5%13%9%4444420%
1575
16th to endDay
16%16%6%9%6%36%445%22%
1461
March1st to 15thDay
14%14%5%8%8%45%34425%
1927
16th to endDay
13%9%48%6%23345%36%
2133
April1st to 15thDay
21%14%45%5%23345%30%
2152
16th to endDay
21%10%36%423235%37%
2295
May1st to 15thDay
19%10%46%5%24445%32%
2472
16th to endDay
15%6%35%5%35%5%5%7%34%
2618
June1st to 15thDay
22%8%36%5%34446%29%
2520
16th to endDay
17%6%25%6%35%5%6%9%29%
2560
July1st to 15thDay
15%6%35%5%35%5%6%7%35%
2520
16th to endDay
12%5%36%6%45%6%6%8%32%
2654
August1st to 15thDay
14%7%38%6%46%6%6%6%30%
2343
16th to endDay
14%6%25%5%36%5%5%9%33%
2395
September1st to 15thDay
19%8%25%5%24446%36%
2160
16th to endDay
17%7%35%423347%39%
1843
October1st to 15thDay
23%10%37%5%33345%29%
1650
16th to endDay
30%14%5%7%5%24335%18%
1734
November1st to 15thDay
18%12%47%6%2345%6%29%
1452
16th to endDay
21%19%6%9%5%33326%17%
1440
December1st to 15thDay
17%22%8%11%7%3433413%
1440
16th to endDay
20%19%8%11%6%23335%16%
1536
January1st to 15thNight
17%15%6%12%9%45%44415%
2506
16th to endNight
12%14%6%10%9%45%5%5%5%20%
2565
February1st to 15thNight
12%14%7%12%8%46%445%19%
2285
16th to endNight
12%15%6%7%6%35%446%26%
2012
March1st to 15thNight
15%12%5%7%7%4444429%
2010
16th to endNight
11%10%46%5%33446%40%
2091
April1st to 15thNight
20%11%37%5%2334432%
1796
16th to endNight
16%9%36%5%33445%36%
1674
May1st to 15thNight
18%7%37%42335%6%37%
1479
16th to endNight
13%6%245%3445%9%40%
1495
June1st to 15thNight
17%7%25%4245%5%8%34%
1440
16th to endNight
13%5%35%5%35%7%6%7%37%
1362
July1st to 15thNight
10%4245%345%47%48%
1440
16th to endNight
10%4245%345%6%9%44%
1514
August1st to 15thNight
9%5%25%4245%6%6%47%
1615
16th to endNight
9%425%5%2445%8%48%
1794
September1st to 15thNight
14%425%4245%5%7%43%
1800
16th to endNight
15%6%25%413445%45%
1863
October1st to 15thNight
20%9%36%5%23345%34%
1980
16th to endNight
24%13%47%6%3345%5%22%
2137
November1st to 15thNight
17%10%45%6%35%446%29%
2405
16th to endNight
21%13%5%8%7%35%335%20%
2520
December1st to 15thNight
19%19%8%10%6%3443415%
2520
16th to endNight
22%16%8%11%6%2433415%
2688

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
18%16%7%11%7%2334420%
1432
16th to endDay
13%14%6%11%9%45%345%20%
1659
February1st to 15thDay
10%17%6%13%10%44435%19%
1575
16th to endDay
15%15%6%8%6%35%435%22%
1461
March1st to 15thDay
15%13%5%8%8%35%44425%
1938
16th to endDay
13%10%47%6%33345%36%
2132
April1st to 15thDay
21%14%445%23345%30%
2152
16th to endDay
21%10%26%423235%37%
2295
May1st to 15thDay
19%9%46%5%24345%32%
2472
16th to endDay
15%6%36%6%245%5%7%34%
2618
June1st to 15thDay
22%8%46%5%3445%6%29%
2520
16th to endDay
17%6%35%5%35%5%7%8%30%
2560
July1st to 15thDay
15%6%35%5%35%5%6%7%35%
2520
16th to endDay
12%6%36%6%36%6%6%8%32%
2654
August1st to 15thDay
14%7%37%6%45%6%5%7%30%
2343
16th to endDay
14%6%25%446%5%6%8%34%
2395
September1st to 15thDay
19%8%25%5%24446%36%
2160
16th to endDay
17%7%35%433437%39%
1843
October1st to 15thDay
22%10%36%5%33336%29%
1650
16th to endDay
29%14%47%6%23245%19%
1734
November1st to 15thDay
17%12%47%5%23446%29%
1452
16th to endDay
21%19%6%9%5%33335%18%
1440
December1st to 15thDay
17%22%7%11%7%4434313%
1440
16th to endDay
19%19%7%11%7%23235%16%
1536
January1st to 15thNight
16%15%6%11%9%45%445%15%
2506
16th to endNight
11%14%6%9%9%45%45%5%21%
2565
February1st to 15thNight
11%15%6%11%8%45%5%46%19%
2278
16th to endNight
12%15%6%7%6%36%446%26%
2012
March1st to 15thNight
15%12%5%8%6%4443429%
2022
16th to endNight
11%10%45%5%33446%40%
2091
April1st to 15thNight
19%12%37%5%3344432%
1796
16th to endNight
16%9%36%5%2335%6%36%
1674
May1st to 15thNight
18%6%36%5%2335%7%37%
1479
16th to endNight
13%6%245%345%5%8%40%
1495
June1st to 15thNight
17%7%25%415%5%5%8%35%
1440
16th to endNight
13%5%35%5%35%6%7%7%37%
1362
July1st to 15thNight
10%4235%335%47%48%
1440
16th to endNight
9%4245%245%5%9%44%
1514
August1st to 15thNight
9%5%25%42446%7%46%
1615
16th to endNight
9%4245%3435%7%49%
1794
September1st to 15thNight
14%415%5%245%5%7%43%
1800
16th to endNight
15%6%24413445%45%
1863
October1st to 15thNight
20%9%35%5%23345%35%
1980
16th to endNight
24%13%37%6%3445%5%22%
2137
November1st to 15thNight
16%10%46%6%35%5%46%29%
2405
16th to endNight
20%14%5%9%7%34435%20%
2520
December1st to 15thNight
18%19%7%10%7%34435%15%
2520
16th to endNight
21%16%7%11%7%34335%15%
2688

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
68%38%11%6%1
1433
16th to endDay
67%28%11%7%2
1659
February1st to 15thDay
67%38%13%5%
1577
16th to endDay
64%28%13%11%
1461
March1st to 15thDay
61%311%15%6%1
1938
16th to endDay
50%37%19%15%4
2133
April1st to 15thDay
57%36%18%11%2
2152
16th to endDay
50%26%22%15%2
2295
May1st to 15thDay
54%47%18%12%2
2472
16th to endDay
47%6%10%20%12%1
2622
June1st to 15thDay
55%5%9%20%8%
2520
16th to endDay
49%7%11%19%11%1
2560
July1st to 15thDay
43%5%10%27%11%
2371
16th to endDay
47%7%12%22%9%
2487
August1st to 15thDay
51%5%13%18%9%
2329
16th to endDay
45%7%13%24%8%
2395
September1st to 15thDay
47%5%10%24%11%
2160
16th to endDay
46%410%29%9%
1843
October1st to 15thDay
57%410%16%10%
1650
16th to endDay
68%48%12%5%
1734
November1st to 15thDay
55%5%13%15%8%
1452
16th to endDay
70%47%11%5%1
1440
December1st to 15thDay
75%47%9%3
1440
16th to endDay
71%36%11%5%
1536
January1st to 15thNight
71%5%7%9%5%
2506
16th to endNight
63%5%6%13%8%1
2565
February1st to 15thNight
64%5%10%12%6%
2287
16th to endNight
57%48%19%9%
2012
March1st to 15thNight
59%210%17%9%1
2022
16th to endNight
45%39%21%17%2
2091
April1st to 15thNight
55%27%19%13%1
1796
16th to endNight
49%47%21%15%2
1674
May1st to 15thNight
47%311%18%16%2
1479
16th to endNight
40%5%13%23%14%1
1497
June1st to 15thNight
46%5%11%21%12%
1440
16th to endNight
43%6%13%24%11%
1362
July1st to 15thNight
33%6%11%28%19%
1360
16th to endNight
34%7%15%29%12%
1418
August1st to 15thNight
35%6%18%27%11%
1605
16th to endNight
32%5%18%32%9%1
1794
September1st to 15thNight
38%7%15%28%10%
1800
16th to endNight
41%5%11%32%8%
1863
October1st to 15thNight
52%410%21%11%
1980
16th to endNight
63%5%10%13%6%
2137
November1st to 15thNight
54%6%12%17%9%
2405
16th to endNight
66%5%9%14%4
2520
December1st to 15thNight
71%5%8%11%3
2520
16th to endNight
73%36%9%6%
2688

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
33%26%25%11%3
60
16th to endDay
34%17%31%15%1
85
February1st to 15thDay
28%32%33%5%
90
16th to endDay
35%22%29%10%2
120
March1st to 15thDay
25%18%33%18%3
270
16th to endDay
21%19%31%17%7%2
288
April1st to 15thDay
27%21%30%13%7%
270
16th to endDay
27%19%25%13%11%1
270
May1st to 15thDay
33%11%26%17%7%4
288
16th to endDay
21%16%33%19%6%2
331
June1st to 15thDay
26%11%34%18%8%
315
16th to endDay
20%11%34%21%9%2
355
July1st to 15thDay
17%8%32%27%11%2
305
16th to endDay
13%9%36%25%11%3
326
August1st to 15thDay
17%432%27%13%5%
313
16th to endDay
19%8%24%27%13%7%
332
September1st to 15thDay
20%6%28%20%13%10%
315
16th to endDay
21%8%27%24%11%7%
266
October1st to 15thDay
25%14%27%20%9%2
255
16th to endDay
39%16%27%13%2
267
November1st to 15thDay
21%12%35%22%6%
106
16th to endDay
41%13%30%13%1
60
December1st to 15thDay
36%20%28%13%1
60
16th to endDay
40%37%17%31
64
January1st to 15thNight
27%22%31%13%3
720
16th to endNight
20%17%36%19%5%1
768
February1st to 15thNight
20%19%40%16%3
704
16th to endNight
20%19%37%17%4
631
March1st to 15thNight
25%21%33%16%3
720
16th to endNight
17%18%32%22%8%1
768
April1st to 15thNight
27%18%30%18%5%
718
16th to endNight
20%18%29%21%10%
594
May1st to 15thNight
23%10%27%28%10%1
399
16th to endNight
18%9%34%28%8%
375
June1st to 15thNight
21%8%32%28%9%
360
16th to endNight
16%8%28%36%9%
360
July1st to 15thNight
10%6%33%32%15%1
340
16th to endNight
9%5%33%34%15%
376
August1st to 15thNight
11%424%36%19%2
534
16th to endNight
11%5%28%33%19%2
648
September1st to 15thNight
18%6%28%26%16%3
720
16th to endNight
20%8%23%27%16%2
673
October1st to 15thNight
25%13%28%22%9%1
660
16th to endNight
32%16%26%18%5%
704
November1st to 15thNight
23%17%29%20%9%
700
16th to endNight
31%16%28%16%5%1
720
December1st to 15thNight
29%22%31%13%2
720
16th to endNight
32%17%32%13%2
768
Page generated at 2017-09-20 04:49:56. Version ac04

Copyright 2017 A. Danko


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