Leitches Creek
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Leitches Creek clear sky chart from 2005-11-05 to 2018-01-12.

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
24%
15730
9%
48372
4%
15687
29%
15687
13%
36953

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
13%
805
6%
2662
1%
802
19%
802
7%
2183
January16th to endNight
12%
797
7%
2675
1%
797
19%
797
7%
2127
February1st to 15thNight
16%
703
7%
2286
2%
701
21%
701
9%
1780
February16th to endNight
17%
631
9%
1945
3%
631
23%
631
10%
1534
March1st to 15thNight
22%
717
12%
2121
5%
717
29%
717
14%
1624
March16th to endNight
22%
678
12%
2022
5%
678
30%
678
13%
1546
April1st to 15thNight
22%
539
12%
1796
7%
539
30%
539
14%
1283
April16th to endNight
22%
540
14%
1689
8%
540
30%
540
17%
1209
May1st to 15thNight
29%
540
12%
1440
6%
540
33%
540
16%
1098
May16th to endNight
25%
561
11%
1496
3%
560
31%
560
19%
1111
June1st to 15thNight
23%
540
5%
1440
2%
540
25%
540
14%
1141
June16th to endNight
27%
540
6%
1440
2%
540
29%
540
18%
1094
July1st to 15thNight
37%
510
8%
1360
4%
510
38%
510
25%
945
July16th to endNight
36%
565
9%
1419
5%
532
38%
532
19%
1073
August1st to 15thNight
42%
539
10%
1473
6%
535
44%
535
20%
1077
August16th to endNight
48%
573
13%
1870
13%
573
51%
573
22%
1234
September1st to 15thNight
37%
540
13%
1800
11%
540
43%
540
19%
1223
September16th to endNight
33%
559
18%
1950
13%
559
41%
559
19%
1291
October1st to 15thNight
29%
720
12%
2160
5%
720
36%
720
20%
1517
October16th to endNight
20%
798
11%
2424
5%
798
26%
798
13%
1880
November1st to 15thNight
23%
805
8%
2532
4%
805
27%
805
12%
2006
November16th to endNight
19%
825
7%
2730
3%
825
24%
825
8%
2198
December1st to 15thNight
14%
825
6%
2730
1%
825
20%
825
7%
2265
December16th to endNight
10%
880
5%
2912
1%
880
15%
880
5%
2514

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
21%11%47%6%3445%6%24%
48975
Night
20%10%47%6%35%446%24%
48543
TransparencyDay
59%5%11%16%6%
48664
Night
58%6%12%16%6%
48372
SeeingDay
26%12%30%20%8%1
8166
Night
25%12%30%23%7%
15735

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
14%12%7%10%10%5%5%45%6%15%
1520
16th to endDay
14%13%6%14%8%46%45%6%15%
1548
February1st to 15thDay
15%11%6%13%8%45%5%6%6%16%
1575
16th to endDay
12%15%7%9%7%34345%24%
1527
March1st to 15thDay
13%13%6%8%7%46%5%45%24%
1829
16th to endDay
17%13%6%7%7%34435%24%
2202
April1st to 15thDay
20%11%47%5%3445%6%27%
2153
16th to endDay
25%11%35%424345%28%
2268
May1st to 15thDay
27%8%45%43444428%
2512
16th to endDay
23%9%36%5%3445%8%26%
2618
June1st to 15thDay
31%9%35%5%2435%6%22%
2520
16th to endDay
23%8%36%7%3345%6%28%
2520
July1st to 15thDay
16%6%345%45%5%5%9%33%
2520
16th to endDay
20%8%46%5%35%46%7%26%
2653
August1st to 15thDay
24%6%26%5%45%5%6%7%27%
2475
16th to endDay
19%7%35%42445%7%33%
2331
September1st to 15thDay
22%8%25%424436%33%
2160
16th to endDay
18%6%25%6%2345%7%35%
2007
October1st to 15thDay
20%10%36%6%2445%9%27%
1800
16th to endDay
26%12%48%7%3444419%
1800
November1st to 15thDay
25%15%5%7%7%3334419%
1653
16th to endDay
17%20%47%6%35%5%6%6%17%
1560
December1st to 15thDay
22%17%6%11%6%45%345%11%
1560
16th to endDay
18%19%8%13%10%35%4338%
1664
January1st to 15thNight
14%13%7%11%9%47%5%6%5%14%
2662
16th to endNight
17%12%6%12%8%46%5%46%15%
2675
February1st to 15thNight
18%10%411%9%37%5%45%20%
2285
16th to endNight
12%13%6%11%9%35%45%6%20%
1945
March1st to 15thNight
16%11%5%6%8%35%435%27%
2108
16th to endNight
20%12%46%5%35%335%28%
2022
April1st to 15thNight
23%8%46%5%34436%29%
1796
16th to endNight
25%8%26%43334434%
1689
May1st to 15thNight
27%8%34323446%29%
1440
16th to endNight
20%8%45%435%449%29%
1494
June1st to 15thNight
29%8%37%6%24445%22%
1440
16th to endNight
25%7%36%42435%7%29%
1440
July1st to 15thNight
16%6%25%5%25%6%6%8%34%
1440
16th to endNight
20%7%35%6%35%5%7%8%27%
1515
August1st to 15thNight
22%5%245%445%47%31%
1484
16th to endNight
16%5%25%5%35%5%6%7%37%
1870
September1st to 15thNight
19%7%2443445%6%37%
1800
16th to endNight
20%6%35%433446%38%
1950
October1st to 15thNight
21%7%25%5%25%448%32%
2160
16th to endNight
24%10%37%5%345%45%25%
2424
November1st to 15thNight
21%13%37%6%3445%6%22%
2532
16th to endNight
19%15%5%7%6%35%5%5%6%19%
2730
December1st to 15thNight
21%15%6%8%7%35%5%5%6%13%
2730
16th to endNight
22%17%6%11%7%36%44410%
2912

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%9%10%11%4
1521
16th to endDay
66%6%9%13%4
1548
February1st to 15thDay
63%6%11%14%4
1578
16th to endDay
59%5%13%12%7%
1527
March1st to 15thDay
60%5%8%17%7%
1839
16th to endDay
63%48%16%6%
2202
April1st to 15thDay
58%410%15%10%1
2153
16th to endDay
59%410%14%9%1
2268
May1st to 15thDay
60%411%16%6%
2512
16th to endDay
56%5%11%19%6%
2622
June1st to 15thDay
64%411%13%5%
2520
16th to endDay
57%6%11%16%8%
2520
July1st to 15thDay
45%7%17%20%8%
2372
16th to endDay
57%5%13%17%5%
2486
August1st to 15thDay
54%6%13%18%5%
2461
16th to endDay
48%6%17%21%5%
2331
September1st to 15thDay
51%5%13%21%7%
2160
16th to endDay
47%413%23%10%
2007
October1st to 15thDay
54%5%12%19%8%
1800
16th to endDay
66%5%10%13%4
1800
November1st to 15thDay
67%5%9%13%3
1653
16th to endDay
65%6%11%11%4
1560
December1st to 15thDay
72%7%9%8%2
1560
16th to endDay
77%6%5%7%2
1664
January1st to 15thNight
64%9%10%11%3
2662
16th to endNight
63%7%11%14%3
2675
February1st to 15thNight
62%6%11%14%5%
2286
16th to endNight
63%5%10%14%5%1
1945
March1st to 15thNight
59%5%10%17%7%
2121
16th to endNight
59%410%16%7%1
2022
April1st to 15thNight
55%410%17%11%
1796
16th to endNight
54%39%17%13%1
1689
May1st to 15thNight
57%49%19%8%
1440
16th to endNight
52%6%12%20%8%
1496
June1st to 15thNight
63%311%16%5%
1440
16th to endNight
54%6%12%16%9%
1440
July1st to 15thNight
45%6%18%19%10%
1360
16th to endNight
53%7%17%16%41
1419
August1st to 15thNight
51%6%16%18%6%
1473
16th to endNight
43%7%18%23%6%
1870
September1st to 15thNight
46%7%13%22%10%
1800
16th to endNight
47%5%11%25%9%
1950
October1st to 15thNight
49%5%16%20%8%
2160
16th to endNight
59%5%10%17%5%
2424
November1st to 15thNight
60%8%13%13%3
2532
16th to endNight
63%8%13%10%4
2730
December1st to 15thNight
65%9%12%10%1
2730
16th to endNight
72%7%7%9%2
2912

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
18%23%38%16%2
273
16th to endDay
25%16%39%16%2
256
February1st to 15thDay
23%20%31%20%2
236
16th to endDay
21%19%29%19%7%1
212
March1st to 15thDay
14%26%29%16%10%2
247
16th to endDay
28%22%25%14%6%2
288
April1st to 15thDay
28%19%30%12%7%1
270
16th to endDay
30%11%31%18%6%
329
May1st to 15thDay
36%9%23%17%9%2
468
16th to endDay
27%9%31%20%9%2
519
June1st to 15thDay
38%6%26%20%7%1
495
16th to endDay
27%6%31%23%8%2
495
July1st to 15thDay
16%434%28%13%1
475
16th to endDay
25%226%29%14%
514
August1st to 15thDay
25%225%29%14%2
448
16th to endDay
23%428%29%11%3
332
September1st to 15thDay
28%7%33%22%6%
315
16th to endDay
23%6%35%22%11%1
282
October1st to 15thDay
22%11%28%19%12%4
270
16th to endDay
25%19%30%13%7%2
288
November1st to 15thDay
27%14%26%18%8%3
280
16th to endDay
27%22%28%15%6%
285
December1st to 15thDay
30%23%28%11%4
285
16th to endDay
26%24%30%14%3
304
January1st to 15thNight
21%20%34%19%2
806
16th to endNight
23%21%34%16%4
797
February1st to 15thNight
24%15%34%23%3
704
16th to endNight
22%19%29%19%8%
631
March1st to 15thNight
23%15%32%23%5%
720
16th to endNight
25%15%30%20%6%1
678
April1st to 15thNight
26%15%29%23%4
539
16th to endNight
30%10%32%19%6%
540
May1st to 15thNight
32%7%25%19%11%2
540
16th to endNight
26%8%33%22%8%
561
June1st to 15thNight
32%7%27%26%5%
540
16th to endNight
27%5%31%28%6%
540
July1st to 15thNight
20%432%34%8%
510
16th to endNight
24%327%32%10%
565
August1st to 15thNight
24%322%33%15%1
539
16th to endNight
19%422%42%11%
573
September1st to 15thNight
21%6%28%30%10%
540
16th to endNight
22%9%30%27%9%
559
October1st to 15thNight
24%8%31%25%9%1
720
16th to endNight
28%13%31%19%6%
798
November1st to 15thNight
27%12%29%21%6%1
805
16th to endNight
28%16%29%19%5%
825
December1st to 15thNight
30%18%29%15%5%
825
16th to endNight
30%19%31%14%31
880
Page generated at 2018-01-12 23:01:29. Version ac04

Copyright 2018 A. Danko


Leitches Creek Clear Sky Chart |Charts Home