La Ronge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the La Ronge clear sky chart from 2005-11-05 to 2017-09-22.

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
40%
15547
9%
46745
6%
15522
43%
15522
17%
34377

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
31%
896
9%
2864
5%
895
34%
895
12%
2265
January16th to endNight
30%
960
10%
2865
6%
960
34%
960
13%
2290
February1st to 15thNight
39%
862
11%
2454
7%
862
43%
862
19%
1808
February16th to endNight
45%
632
11%
2033
9%
632
47%
632
15%
1510
March1st to 15thNight
38%
720
14%
2157
11%
720
42%
720
17%
1587
March16th to endNight
43%
663
17%
2007
14%
663
48%
663
20%
1424
April1st to 15thNight
48%
539
13%
1792
12%
539
51%
539
21%
1208
April16th to endNight
44%
540
16%
1442
10%
540
46%
540
26%
1000
May1st to 15thNight
51%
539
6%
1416
4%
539
52%
539
29%
963
May16th to endNight
51%
387
0%
1136
0%
387
51%
387
25%
748
June1st to 15thNight
48%
360
0%
1080
0%
360
48%
360
25%
724
June16th to endNight
48%
360
0%
1080
0%
360
48%
360
19%
788
July1st to 15thNight
60%
340
0%
1020
0%
340
60%
340
33%
620
July16th to endNight
60%
376
0%
1150
1%
354
60%
354
26%
714
August1st to 15thNight
65%
527
6%
1421
4%
525
66%
525
36%
876
August16th to endNight
56%
573
13%
1633
8%
573
59%
573
30%
1031
September1st to 15thNight
54%
540
11%
1800
12%
540
56%
540
26%
1106
September16th to endNight
45%
553
17%
1862
16%
553
50%
553
26%
1141
October1st to 15thNight
32%
665
13%
1985
8%
665
37%
665
17%
1467
October16th to endNight
27%
880
10%
2335
4%
880
31%
880
15%
1846
November1st to 15thNight
27%
875
9%
2510
5%
875
30%
875
11%
2048
November16th to endNight
25%
900
5%
2751
2%
900
28%
900
9%
2319
December1st to 15thNight
31%
900
4%
2880
3%
900
33%
900
8%
2438
December16th to endNight
34%
960
9%
3072
7%
960
37%
960
11%
2456

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
13%9%47%6%35%5%6%7%31%
48186
Night
12%10%48%7%46%5%5%6%27%
46878
TransparencyDay
49%416%22%7%
47823
Night
55%413%19%6%
46746
SeeingDay
16%320%31%21%5%
6275
Night
18%422%33%17%3
15561

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
10%13%6%11%9%47%5%6%6%18%
1074
16th to endDay
10%13%6%9%7%46%7%6%7%20%
1358
February1st to 15thDay
5%9%410%9%6%11%6%5%6%23%
1420
16th to endDay
7%11%5%10%8%48%7%6%6%23%
1441
March1st to 15thDay
11%12%5%8%6%45%5%46%31%
1800
16th to endDay
10%10%46%7%36%5%5%6%32%
2216
April1st to 15thDay
11%8%36%5%35%5%47%37%
2156
16th to endDay
11%8%47%6%36%5%6%6%33%
2517
May1st to 15thDay
12%7%36%6%345%5%6%39%
2533
16th to endDay
16%7%244245%5%6%39%
2973
June1st to 15thDay
15%7%26%7%36%5%6%7%30%
2880
16th to endDay
17%7%46%5%36%6%8%7%25%
2880
July1st to 15thDay
13%5%25%435%5%6%8%38%
2880
16th to endDay
12%425%5%36%6%7%8%36%
2937
August1st to 15thDay
11%5%24435%5%6%8%41%
2532
16th to endDay
12%6%25%5%35%5%6%8%37%
2567
September1st to 15thDay
13%5%26%6%345%5%7%38%
2160
16th to endDay
17%11%36%32345%7%34%
1909
October1st to 15thDay
20%12%5%6%42335%6%28%
1633
16th to endDay
20%16%49%434435%22%
1535
November1st to 15thDay
18%17%7%8%6%4443420%
1347
16th to endDay
11%13%8%15%9%35%45%5%17%
1206
December1st to 15thDay
8%14%6%10%9%6%8%6%8%6%13%
1080
16th to endDay
8%14%5%11%11%5%7%6%7%6%14%
1152
January1st to 15thNight
10%15%6%9%8%5%7%6%6%419%
2864
16th to endNight
10%14%6%8%7%47%8%6%6%18%
2865
February1st to 15thNight
8%9%49%7%49%7%6%6%26%
2443
16th to endNight
6%10%6%10%10%5%7%5%5%6%25%
2033
March1st to 15thNight
10%11%6%8%7%45%45%6%28%
2157
16th to endNight
11%11%48%6%5%5%5%6%7%28%
2004
April1st to 15thNight
13%9%36%6%35%45%6%34%
1792
16th to endNight
13%10%46%5%24437%36%
1442
May1st to 15thNight
12%7%35%445%5%5%5%39%
1416
16th to endNight
16%6%245%35%45%7%37%
1136
June1st to 15thNight
14%426%7%35%6%7%9%32%
1080
16th to endNight
19%7%38%6%35%46%7%28%
1080
July1st to 15thNight
12%41442446%13%40%
1080
16th to endNight
11%5%35%5%35%45%7%40%
1230
August1st to 15thNight
13%3134246%5%9%44%
1428
16th to endNight
12%4234445%7%9%40%
1633
September1st to 15thNight
11%6%25%6%245%6%7%41%
1800
16th to endNight
14%6%144245%6%9%40%
1862
October1st to 15thNight
22%12%46%423347%29%
1985
16th to endNight
17%15%5%8%6%24445%25%
2335
November1st to 15thNight
17%15%6%11%7%3443421%
2510
16th to endNight
10%14%6%12%11%5%7%5%45%17%
2751
December1st to 15thNight
10%13%7%11%11%6%8%7%5%5%12%
2880
16th to endNight
10%13%6%11%9%5%6%6%6%5%17%
3072

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
64%411%16%3
1074
16th to endDay
59%5%14%15%5%
1358
February1st to 15thDay
58%412%18%6%
1420
16th to endDay
58%314%18%5%
1441
March1st to 15thDay
53%413%23%4
1800
16th to endDay
47%314%27%6%
2217
April1st to 15thDay
44%315%24%9%1
2156
16th to endDay
47%312%23%11%1
2517
May1st to 15thDay
43%210%29%13%1
2533
16th to endDay
41%313%22%15%2
2978
June1st to 15thDay
48%312%24%10%
2880
16th to endDay
51%416%20%6%
2880
July1st to 15thDay
38%318%28%8%
2711
16th to endDay
39%5%25%24%5%
2754
August1st to 15thDay
35%328%27%3
2515
16th to endDay
40%426%24%2
2567
September1st to 15thDay
41%5%21%21%8%
2160
16th to endDay
49%320%21%5%
1909
October1st to 15thDay
56%415%19%4
1633
16th to endDay
66%313%14%1
1535
November1st to 15thDay
69%38%14%4
1347
16th to endDay
69%414%9%1
1206
December1st to 15thDay
66%7%11%11%3
1080
16th to endDay
65%5%13%14%1
1152
January1st to 15thNight
63%5%11%16%2
2864
16th to endNight
63%5%11%15%4
2865
February1st to 15thNight
54%416%18%6%
2454
16th to endNight
57%5%11%19%6%
2033
March1st to 15thNight
56%311%20%6%
2157
16th to endNight
52%310%24%7%1
2007
April1st to 15thNight
49%312%21%10%2
1792
16th to endNight
48%27%24%14%2
1442
May1st to 15thNight
44%27%27%15%2
1417
16th to endNight
44%47%22%18%2
1136
June1st to 15thNight
44%412%23%13%
1080
16th to endNight
54%411%20%7%1
1080
July1st to 15thNight
35%417%32%10%
1020
16th to endNight
41%322%26%5%
1150
August1st to 15thNight
33%5%23%31%6%
1421
16th to endNight
37%6%23%28%4
1633
September1st to 15thNight
40%5%20%22%10%1
1800
16th to endNight
39%418%28%6%
1862
October1st to 15thNight
57%313%20%4
1985
16th to endNight
61%414%17%1
2335
November1st to 15thNight
68%311%12%3
2510
16th to endNight
69%7%12%9%1
2751
December1st to 15thNight
71%5%12%7%2
2880
16th to endNight
65%5%12%14%2
3072

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
1326%40%25%3
60
16th to endDay
20%222%40%11%1
67
February1st to 15thDay
4231%50%10%2
90
16th to endDay
19%323%27%24%1
81
March1st to 15thDay
23%124%27%21%2
90
16th to endDay
18%424%35%13%3
288
April1st to 15thDay
18%5%23%37%11%2
269
16th to endDay
14%223%32%21%5%
447
May1st to 15thDay
15%421%33%19%4
468
16th to endDay
16%216%29%26%8%
517
June1st to 15thDay
16%5%19%32%21%4
495
16th to endDay
20%216%31%20%7%
495
July1st to 15thDay
16%316%31%27%4
475
16th to endDay
13%219%33%24%7%
515
August1st to 15thDay
13%113%26%28%15%
493
16th to endDay
12%321%35%22%4
452
September1st to 15thDay
14%8%24%32%17%2
315
16th to endDay
24%5%23%26%15%4
177
October1st to 15thDay
36%222%31%6%1
90
16th to endDay
37%5%16%21%14%4
96
November1st to 15thDay
18%6%28%28%16%
90
16th to endDay
20%9%25%27%12%3
81
December1st to 15thDay
20%115%28%25%10%
60
16th to endDay
10%45%21%18%3
64
January1st to 15thNight
17%5%26%32%15%2
900
16th to endNight
19%5%29%34%9%2
960
February1st to 15thNight
14%226%35%17%3
870
16th to endNight
10%318%38%23%4
632
March1st to 15thNight
17%325%35%15%2
720
16th to endNight
16%321%30%23%4
663
April1st to 15thNight
20%119%38%15%3
539
16th to endNight
19%221%35%18%3
540
May1st to 15thNight
16%120%37%19%3
540
16th to endNight
17%416%37%19%3
388
June1st to 15thNight
16%218%31%26%4
360
16th to endNight
22%213%32%23%5%
360
July1st to 15thNight
15%213%35%30%2
340
16th to endNight
14%212%35%26%9%
376
August1st to 15thNight
15%111%27%32%12%
527
16th to endNight
15%317%36%22%4
573
September1st to 15thNight
15%216%36%26%1
540
16th to endNight
17%426%35%14%1
553
October1st to 15thNight
31%6%19%29%11%1
665
16th to endNight
27%10%24%26%9%2
880
November1st to 15thNight
25%7%23%28%11%2
875
16th to endNight
17%6%32%31%11%1
900
December1st to 15thNight
15%423%35%16%4
900
16th to endNight
15%420%32%21%5%
960
Page generated at 2017-09-23 04:43:47. Version ac04

Copyright 2017 A. Danko


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