Whitemud Lake Gravel Pit
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Whitemud Lake Gravel Pit clear sky chart from 2005-11-05 to 2017-09-23.

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%
15224
11%
46553
7%
15198
45%
15198
20%
32370

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%
895
6%
2685
3%
895
34%
895
13%
2075
January16th to endNight
30%
942
15%
2862
8%
942
38%
942
18%
2035
February1st to 15thNight
38%
699
10%
2431
9%
697
41%
697
16%
1706
February16th to endNight
45%
632
14%
2046
13%
632
50%
632
19%
1424
March1st to 15thNight
37%
720
15%
2101
10%
720
41%
720
21%
1496
March16th to endNight
38%
767
12%
2106
8%
767
40%
767
18%
1580
April1st to 15thNight
41%
578
13%
1658
9%
578
44%
578
23%
1136
April16th to endNight
40%
540
13%
1611
10%
540
44%
540
20%
1123
May1st to 15thNight
50%
377
8%
1277
6%
377
52%
377
24%
787
May16th to endNight
44%
374
0%
1309
0%
374
45%
374
18%
895
June1st to 15thNight
47%
360
0%
1230
0%
360
47%
360
19%
835
June16th to endNight
53%
360
0%
1080
0%
360
53%
360
23%
737
July1st to 15thNight
60%
340
0%
1117
0%
340
60%
340
27%
674
July16th to endNight
60%
376
1%
1239
0%
354
61%
354
29%
714
August1st to 15thNight
66%
371
7%
1354
7%
369
67%
369
28%
773
August16th to endNight
55%
573
14%
1719
11%
573
59%
573
29%
1065
September1st to 15thNight
57%
600
15%
1758
11%
600
59%
600
34%
1060
September16th to endNight
48%
688
20%
1903
11%
688
55%
688
35%
1151
October1st to 15thNight
41%
660
15%
1979
10%
660
46%
660
23%
1372
October16th to endNight
36%
737
16%
2321
10%
737
43%
737
19%
1573
November1st to 15thNight
34%
875
14%
2487
8%
875
40%
875
18%
1842
November16th to endNight
29%
900
9%
2700
3%
900
34%
900
15%
2032
December1st to 15thNight
29%
900
8%
2700
4%
900
32%
900
12%
2130
December16th to endNight
34%
960
11%
2880
5%
960
40%
960
15%
2155

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
11%9%47%6%46%5%6%8%29%
48389
Night
9%9%48%7%45%5%6%7%31%
46705
TransparencyDay
51%418%20%5%
48038
Night
50%416%21%6%
46561
SeeingDay
15%5%22%30%19%6%
6442
Night
13%425%35%17%3
15237

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
6%13%7%9%8%49%5%6%7%20%
1253
16th to endDay
7%9%6%11%8%45%45%7%28%
1372
February1st to 15thDay
7%12%49%8%47%6%6%7%24%
1425
16th to endDay
6%11%7%11%8%46%7%6%7%21%
1428
March1st to 15thDay
7%12%7%10%9%45%6%7%7%21%
1858
16th to endDay
11%12%6%10%7%45%5%6%7%22%
2116
April1st to 15thDay
10%12%47%6%35%45%7%30%
2290
16th to endDay
12%11%48%7%45%5%6%8%25%
2349
May1st to 15thDay
11%7%37%7%46%5%5%7%33%
2671
16th to endDay
15%9%36%5%35%5%6%7%30%
2802
June1st to 15thDay
17%8%37%6%47%6%6%7%25%
2728
16th to endDay
15%7%47%6%45%5%6%8%27%
2880
July1st to 15thDay
11%425%7%35%6%6%10%36%
2772
16th to endDay
10%5%35%5%36%6%6%9%35%
2846
August1st to 15thDay
11%5%26%5%45%6%7%9%35%
2598
16th to endDay
8%5%27%6%35%5%7%10%35%
2483
September1st to 15thDay
11%8%37%5%3445%7%38%
2201
16th to endDay
11%6%25%5%3445%7%41%
1893
October1st to 15thDay
12%11%47%6%335%5%8%33%
1651
16th to endDay
10%10%46%6%3446%7%34%
1540
November1st to 15thDay
10%11%5%8%6%36%5%6%6%30%
1369
16th to endDay
6%12%5%11%10%35%5%47%27%
1260
December1st to 15thDay
8%12%6%9%8%6%9%7%7%7%16%
1260
16th to endDay
5%9%6%13%9%5%9%6%7%8%18%
1344
January1st to 15thNight
7%12%5%10%10%48%6%5%6%21%
2685
16th to endNight
6%10%410%9%45%45%7%30%
2862
February1st to 15thNight
6%9%5%10%8%46%5%6%7%28%
2427
16th to endNight
5%10%5%8%7%6%6%6%7%7%29%
2046
March1st to 15thNight
6%10%6%9%7%35%5%7%7%29%
2101
16th to endNight
9%11%6%9%7%46%46%8%24%
2103
April1st to 15thNight
10%8%36%7%36%5%6%6%33%
1658
16th to endNight
12%12%27%5%26%45%7%31%
1611
May1st to 15thNight
10%5%37%5%36%6%6%7%37%
1277
16th to endNight
18%9%25%6%45%35%8%30%
1309
June1st to 15thNight
15%8%37%7%345%6%9%28%
1230
16th to endNight
12%6%37%7%45%6%7%7%32%
1080
July1st to 15thNight
8%425%5%35%47%8%42%
1185
16th to endNight
9%435%5%27%5%6%9%41%
1323
August1st to 15thNight
6%4246%46%5%8%10%41%
1361
16th to endNight
9%6%25%5%35%6%6%8%41%
1719
September1st to 15thNight
11%5%25%5%23448%47%
1758
16th to endNight
11%41442445%9%47%
1903
October1st to 15thNight
12%10%47%6%3446%7%32%
1979
16th to endNight
9%10%48%6%345%6%8%32%
2321
November1st to 15thNight
12%11%47%7%45%446%29%
2487
16th to endNight
5%11%7%11%9%45%5%5%7%25%
2700
December1st to 15thNight
8%13%6%11%10%5%6%5%5%7%19%
2700
16th to endNight
5%10%5%11%9%5%7%7%7%8%21%
2880

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
62%316%10%5%
1253
16th to endDay
54%412%19%7%1
1372
February1st to 15thDay
56%418%14%5%
1425
16th to endDay
60%414%16%5%
1428
March1st to 15thDay
60%414%15%4
1858
16th to endDay
58%414%16%5%
2117
April1st to 15thDay
52%416%19%6%
2290
16th to endDay
56%313%18%7%
2349
May1st to 15thDay
47%312%24%10%
2671
16th to endDay
50%412%21%10%
2807
June1st to 15thDay
55%414%20%3
2728
16th to endDay
53%5%16%19%4
2880
July1st to 15thDay
41%425%23%3
2612
16th to endDay
42%5%29%19%1
2667
August1st to 15thDay
41%6%31%18%2
2580
16th to endDay
41%5%28%20%4
2483
September1st to 15thDay
44%321%22%6%1
2201
16th to endDay
41%419%27%6%1
1893
October1st to 15thDay
50%317%23%3
1651
16th to endDay
48%416%27%3
1540
November1st to 15thDay
51%418%20%4
1369
16th to endDay
56%416%17%3
1260
December1st to 15thDay
63%413%15%2
1260
16th to endDay
61%5%11%16%5%
1344
January1st to 15thNight
61%416%13%3
2685
16th to endNight
52%414%19%7%1
2862
February1st to 15thNight
53%316%18%7%
2438
16th to endNight
51%414%21%7%
2046
March1st to 15thNight
51%314%22%6%
2101
16th to endNight
56%411%19%7%
2106
April1st to 15thNight
48%313%24%9%1
1658
16th to endNight
50%311%19%13%1
1611
May1st to 15thNight
42%311%26%14%1
1278
16th to endNight
52%311%20%9%1
1309
June1st to 15thNight
50%317%21%6%
1230
16th to endNight
47%419%21%41
1080
July1st to 15thNight
37%5%23%28%4
1117
16th to endNight
35%425%29%3
1239
August1st to 15thNight
35%5%31%25%2
1354
16th to endNight
38%422%27%6%
1719
September1st to 15thNight
36%220%30%7%1
1758
16th to endNight
33%319%29%10%2
1903
October1st to 15thNight
49%313%26%6%
1979
16th to endNight
49%416%25%4
2321
November1st to 15thNight
55%312%22%5%
2487
16th to endNight
57%5%18%14%3
2700
December1st to 15thNight
63%413%13%3
2700
16th to endNight
57%416%16%4
2880

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
6%325%40%20%5%
60
16th to endDay
6%326%42%10%10%
64
February1st to 15thDay
12%435%30%12%4
65
16th to endDay
14%416%41%20%2
87
March1st to 15thDay
12%5%40%27%10%3
270
16th to endDay
20%5%30%28%11%2
288
April1st to 15thDay
13%8%35%28%11%2
269
16th to endDay
23%8%25%27%11%2
279
May1st to 15thDay
15%7%19%30%20%7%
468
16th to endDay
19%416%28%23%7%
517
June1st to 15thDay
19%5%21%30%17%5%
523
16th to endDay
16%5%16%30%24%7%
675
July1st to 15thDay
11%215%35%27%7%
546
16th to endDay
12%220%29%26%7%
515
August1st to 15thDay
13%114%28%26%15%
404
16th to endDay
6%7%32%32%18%2
332
September1st to 15thDay
18%7%25%26%16%5%
315
16th to endDay
16%11%27%29%11%3
284
October1st to 15thDay
28%7%22%22%11%5%
118
16th to endDay
25%6%19%21%25%2
96
November1st to 15thDay
19%227%39%8%2
83
16th to endDay
8%130%23%23%13%
60
December1st to 15thDay
18%31%23%21%5%
60
16th to endDay
3334%31%17%10%
64
January1st to 15thNight
13%5%30%35%12%2
900
16th to endNight
9%9%33%33%11%2
942
February1st to 15thNight
12%425%35%19%2
704
16th to endNight
8%225%40%19%3
632
March1st to 15thNight
10%430%38%12%3
720
16th to endNight
15%424%35%16%3
768
April1st to 15thNight
14%5%23%36%16%3
578
16th to endNight
20%5%22%30%18%2
540
May1st to 15thNight
14%318%38%21%3
378
16th to endNight
22%416%29%24%2
375
June1st to 15thNight
16%316%38%21%3
360
16th to endNight
15%115%35%27%4
360
July1st to 15thNight
11%115%44%25%1
340
16th to endNight
11%214%40%26%3
376
August1st to 15thNight
8%111%37%33%7%
371
16th to endNight
11%220%37%26%1
573
September1st to 15thNight
15%216%35%27%2
600
16th to endNight
14%426%36%16%2
688
October1st to 15thNight
16%225%35%16%3
660
16th to endNight
15%428%35%15%1
737
November1st to 15thNight
18%5%29%32%11%3
875
16th to endNight
10%5%35%31%13%2
900
December1st to 15thNight
16%6%28%29%15%2
900
16th to endNight
10%5%28%34%16%4
960
Page generated at 2017-09-24 07:15:53. Version ac04

Copyright 2017 A. Danko


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