AUGO Fort Vermillion
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the AUGO Fort Vermillion clear sky chart from 2005-11-05 to 2017-09-10.

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
43%
15140
8%
46557
5%
15109
45%
15109
17%
34044

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
32%
929
5%
2898
2%
925
35%
925
9%
2384
January16th to endNight
36%
988
11%
3048
7%
988
41%
988
16%
2258
February1st to 15thNight
47%
712
10%
2476
10%
709
50%
709
18%
1693
February16th to endNight
44%
632
11%
2107
11%
632
47%
632
15%
1556
March1st to 15thNight
40%
720
14%
2160
11%
720
44%
720
19%
1550
March16th to endNight
45%
768
13%
2026
7%
768
48%
768
23%
1455
April1st to 15thNight
45%
611
12%
1691
10%
611
47%
611
23%
1191
April16th to endNight
41%
402
8%
1461
8%
402
44%
402
17%
1004
May1st to 15thNight
50%
359
0%
1260
0%
359
50%
359
21%
809
May16th to endNight
53%
374
0%
1082
0%
374
53%
374
27%
706
June1st to 15thNight
51%
360
0%
900
0%
360
51%
360
23%
675
June16th to endNight
56%
360
0%
900
0%
360
56%
360
24%
653
July1st to 15thNight
58%
340
0%
914
0%
340
58%
340
22%
670
July16th to endNight
63%
376
0%
1062
0%
354
64%
354
26%
689
August1st to 15thNight
70%
360
0%
1313
0%
358
70%
358
23%
800
August16th to endNight
53%
460
9%
1606
9%
460
56%
460
22%
1022
September1st to 15thNight
56%
628
10%
1678
6%
628
58%
628
29%
1107
September16th to endNight
41%
656
10%
1815
5%
656
44%
656
20%
1342
October1st to 15thNight
44%
660
10%
2041
7%
660
49%
660
17%
1484
October16th to endNight
35%
736
8%
2336
5%
736
39%
736
15%
1764
November1st to 15thNight
37%
875
11%
2625
8%
875
40%
875
15%
1968
November16th to endNight
34%
912
7%
2834
5%
912
37%
912
13%
2181
December1st to 15thNight
29%
930
4%
3060
3%
930
31%
930
9%
2501
December16th to endNight
37%
992
7%
3264
4%
992
40%
992
10%
2582

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
10%8%47%6%36%5%6%8%32%
48141
Night
9%10%48%7%45%5%6%7%29%
46674
TransparencyDay
47%9%18%18%5%
47764
Night
51%8%16%17%5%
46557
SeeingDay
13%7%23%28%21%5%
7069
Night
14%5%22%34%19%2
15147

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
14%11%6%11%8%5%8%46%6%17%
1040
16th to endDay
10%12%5%8%7%35%45%8%27%
1176
February1st to 15thDay
8%11%48%7%5%8%6%5%6%27%
1400
16th to endDay
7%13%6%9%8%6%6%5%5%8%22%
1365
March1st to 15thDay
8%11%5%10%7%47%46%7%26%
1800
16th to endDay
7%12%5%7%5%3445%7%35%
2197
April1st to 15thDay
6%7%46%6%46%7%7%7%35%
2257
16th to endDay
9%8%37%7%45%5%6%6%34%
2498
May1st to 15thDay
9%6%35%4345%6%9%40%
2691
16th to endDay
12%5%35%5%35%447%40%
3028
June1st to 15thDay
12%6%37%7%36%6%6%8%30%
3060
16th to endDay
14%5%36%5%35%5%7%10%33%
3060
July1st to 15thDay
12%6%36%6%46%5%7%8%31%
2988
16th to endDay
10%435%5%37%6%7%9%36%
3035
August1st to 15thDay
9%5%25%5%36%5%6%9%40%
2639
16th to endDay
12%6%25%6%46%6%6%8%34%
2596
September1st to 15thDay
12%5%25%42446%8%43%
2169
16th to endDay
14%9%47%5%2445%7%33%
1815
October1st to 15thDay
13%9%47%6%35%47%7%30%
1589
16th to endDay
12%16%47%6%45%5%5%6%24%
1521
November1st to 15thDay
11%12%6%8%6%3345%6%30%
1232
16th to endDay
10%12%6%11%9%46%6%47%19%
1125
December1st to 15thDay
10%16%7%10%10%6%6%347%16%
900
16th to endDay
8%13%6%12%12%47%5%6%5%17%
960
January1st to 15thNight
9%14%7%11%10%47%5%5%6%16%
2898
16th to endNight
7%12%49%7%46%5%5%8%28%
3048
February1st to 15thNight
5%10%5%9%6%46%5%5%7%32%
2464
16th to endNight
7%11%6%10%7%46%5%5%6%28%
2107
March1st to 15thNight
8%10%7%9%5%35%45%5%33%
2160
16th to endNight
7%10%47%6%36%5%5%6%35%
2023
April1st to 15thNight
6%10%46%5%36%6%7%7%35%
1691
16th to endNight
10%9%46%6%36%6%6%9%30%
1461
May1st to 15thNight
10%6%26%6%36%5%7%9%33%
1259
16th to endNight
12%5%25%5%25%5%8%8%38%
1082
June1st to 15thNight
12%8%37%5%36%7%6%8%32%
900
16th to endNight
12%6%35%7%26%5%7%7%36%
900
July1st to 15thNight
11%436%6%5%6%6%7%10%30%
969
16th to endNight
7%5%27%435%5%8%11%37%
1134
August1st to 15thNight
6%335%5%36%7%7%9%41%
1319
16th to endNight
10%5%26%5%445%6%8%39%
1606
September1st to 15thNight
12%425%5%345%6%8%43%
1678
16th to endNight
16%7%36%6%35%6%5%8%30%
1815
October1st to 15thNight
10%8%37%6%46%6%6%7%33%
2041
16th to endNight
11%16%37%6%3445%7%28%
2336
November1st to 15thNight
13%12%5%8%6%3446%7%27%
2625
16th to endNight
11%12%5%10%7%45%46%8%23%
2834
December1st to 15thNight
11%14%6%10%10%5%5%447%18%
3060
16th to endNight
8%12%6%12%9%46%6%7%7%18%
3264

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%7%13%11%3
1040
16th to endDay
54%7%16%14%5%1
1176
February1st to 15thDay
53%8%15%17%5%
1400
16th to endDay
58%8%15%14%3
1365
March1st to 15thDay
54%7%15%17%3
1800
16th to endDay
46%7%18%22%4
2198
April1st to 15thDay
43%10%16%17%11%
2257
16th to endDay
47%7%13%20%10%
2498
May1st to 15thDay
38%9%16%24%11%
2691
16th to endDay
42%7%12%21%14%1
3033
June1st to 15thDay
47%9%17%17%7%
3060
16th to endDay
43%11%19%20%5%
3060
July1st to 15thDay
46%12%22%15%3
2815
16th to endDay
40%13%27%18%1
2844
August1st to 15thDay
38%12%27%19%2
2620
16th to endDay
45%12%22%17%2
2596
September1st to 15thDay
37%10%29%19%3
2169
16th to endDay
48%9%19%19%2
1815
October1st to 15thDay
50%9%16%19%3
1589
16th to endDay
58%11%15%12%2
1521
November1st to 15thDay
55%6%17%16%3
1232
16th to endDay
63%8%14%11%1
1125
December1st to 15thDay
67%8%12%10%
900
16th to endDay
64%8%11%13%1
960
January1st to 15thNight
65%8%12%9%3
2898
16th to endNight
52%8%17%14%5%1
3048
February1st to 15thNight
49%6%19%18%6%
2476
16th to endNight
54%7%13%20%3
2107
March1st to 15thNight
51%6%13%21%7%
2160
16th to endNight
47%6%13%23%8%
2026
April1st to 15thNight
44%9%12%21%10%2
1691
16th to endNight
47%8%12%16%13%1
1461
May1st to 15thNight
42%7%10%23%14%1
1260
16th to endNight
39%7%11%19%18%3
1082
June1st to 15thNight
46%10%14%20%7%
900
16th to endNight
43%11%15%22%7%1
900
July1st to 15thNight
44%12%20%17%4
914
16th to endNight
35%11%27%22%1
1062
August1st to 15thNight
34%11%25%21%5%
1313
16th to endNight
39%9%22%22%4
1606
September1st to 15thNight
35%10%23%22%6%
1678
16th to endNight
50%8%18%16%5%
1815
October1st to 15thNight
47%11%16%18%5%
2041
16th to endNight
54%9%20%13%1
2336
November1st to 15thNight
54%8%16%18%2
2625
16th to endNight
57%8%15%15%1
2834
December1st to 15thNight
64%8%16%9%1
3060
16th to endNight
60%9%13%14%1
3264

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
5%5%25%38%20%6%
60
16th to endDay
31%115%35%14%1
64
February1st to 15thDay
15%8%13%35%21%6%
60
16th to endDay
16%6%30%26%20%1
99
March1st to 15thDay
12%12%28%26%15%4
270
16th to endDay
12%13%30%31%10%1
288
April1st to 15thDay
5%13%37%31%10%1
269
16th to endDay
14%9%27%29%17%
291
May1st to 15thDay
11%9%25%24%20%8%
468
16th to endDay
12%7%20%27%25%6%
697
June1st to 15thDay
13%6%26%29%20%3
675
16th to endDay
12%320%29%26%7%
675
July1st to 15thDay
12%421%29%24%6%
645
16th to endDay
10%417%28%29%9%
703
August1st to 15thDay
11%314%27%30%13%
432
16th to endDay
17%9%29%28%13%1
332
September1st to 15thDay
17%6%24%27%16%8%
294
16th to endDay
14%12%32%22%13%3
255
October1st to 15thDay
20%9%24%26%16%2
155
16th to endDay
33%9%20%22%8%5%
93
November1st to 15thDay
10%25%43%20%1
60
16th to endDay
23%6%8%36%23%1
60
December1st to 15thDay
28%6%25%28%10%1
60
16th to endDay
7%320%35%25%7%
64
January1st to 15thNight
16%422%34%18%2
930
16th to endNight
14%6%27%36%12%1
988
February1st to 15thNight
11%5%20%38%19%5%
716
16th to endNight
12%422%40%18%1
632
March1st to 15thNight
12%7%27%31%18%2
720
16th to endNight
11%7%23%34%19%2
768
April1st to 15thNight
11%6%27%35%17%2
611
16th to endNight
16%6%25%33%16%1
402
May1st to 15thNight
12%423%33%23%2
360
16th to endNight
12%5%19%35%25%1
375
June1st to 15thNight
15%416%32%27%2
360
16th to endNight
13%213%38%26%4
360
July1st to 15thNight
11%215%40%26%2
340
16th to endNight
9%214%29%38%6%
376
August1st to 15thNight
7%210%37%34%8%
360
16th to endNight
13%123%32%26%2
460
September1st to 15thNight
13%317%37%25%4
628
16th to endNight
18%5%24%33%15%2
656
October1st to 15thNight
14%7%25%34%17%1
660
16th to endNight
22%426%32%12%2
736
November1st to 15thNight
17%6%24%32%16%1
875
16th to endNight
17%425%32%16%2
912
December1st to 15thNight
19%6%26%31%13%2
930
16th to endNight
12%5%19%34%21%5%
992
Page generated at 2017-09-11 17:35:16. Version ac04

Copyright 2017 A. Danko


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