Vekol Road
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Vekol Road clear sky chart from 2005-11-05 to 2017-04-08.

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
76%
15198
38%
45416
33%
15159
81%
15159
57%
21016

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
75%
718
34%
2327
34%
716
79%
716
49%
1092
January16th to endNight
68%
768
38%
2496
37%
768
76%
768
45%
1226
February1st to 15thNight
72%
700
39%
2145
36%
699
80%
699
55%
979
February16th to endNight
67%
632
37%
1895
35%
632
74%
632
45%
964
March1st to 15thNight
65%
720
41%
1980
32%
720
74%
720
58%
972
March16th to endNight
72%
768
41%
2112
30%
768
81%
768
63%
986
April1st to 15thNight
60%
691
36%
1901
21%
691
71%
691
56%
934
April16th to endNight
67%
507
44%
1558
32%
507
79%
507
71%
607
May1st to 15thNight
70%
494
42%
1484
30%
494
79%
494
66%
613
May16th to endNight
73%
513
39%
1540
29%
513
79%
513
72%
618
June1st to 15thNight
83%
495
38%
1485
31%
495
86%
495
74%
594
June16th to endNight
88%
495
33%
1485
29%
495
88%
495
73%
603
July1st to 15thNight
81%
465
27%
1395
22%
465
82%
465
49%
696
July16th to endNight
86%
522
30%
1467
26%
489
88%
489
46%
764
August1st to 15thNight
86%
494
34%
1476
29%
491
86%
491
51%
718
August16th to endNight
82%
628
34%
1744
29%
628
82%
628
51%
921
September1st to 15thNight
82%
660
34%
1815
29%
660
83%
660
54%
928
September16th to endNight
85%
656
45%
1815
36%
656
89%
656
73%
788
October1st to 15thNight
78%
660
44%
1873
34%
660
85%
660
67%
837
October16th to endNight
84%
704
44%
2112
38%
704
89%
704
69%
873
November1st to 15thNight
84%
700
42%
2135
42%
700
87%
700
63%
941
November16th to endNight
74%
720
41%
2340
41%
720
80%
720
56%
1021
December1st to 15thNight
73%
720
37%
2340
38%
720
77%
720
47%
1114
December16th to endNight
70%
768
37%
2496
38%
768
75%
768
45%
1227

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
2212213346%68%
45841
Night
2212213346%69%
45614
TransparencyDay
17%2311%25%40%
45536
Night
16%2311%24%40%
45420
SeeingDay
45%17%32%28%11%
4872
Night
3211%36%37%8%
15207

By Month

Percentage Cloud Cover SW (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
2214323336%66%
1611
16th to endDay
5%313212346%63%
1728
February1st to 15thDay
222321235%6%68%
1715
16th to endDay
4212324247%62%
1579
March1st to 15thDay
3112213335%68%
1980
16th to endDay
1212322335%71%
2112
April1st to 15thDay
111212347%71%
1886
16th to endDay
111112481%
2068
May1st to 15thDay
11111223478%
2136
16th to endDay
11111212383%
2221
June1st to 15thDay
1111212482%
2145
16th to endDay
111111222381%
2145
July1st to 15thDay
3313435%46%9%55%
2145
16th to endDay
4425%6%37%7%9%10%39%
2285
August1st to 15thDay
3313436%6%7%8%51%
2145
16th to endDay
3213435%5%5%9%54%
2104
September1st to 15thDay
421343445%6%60%
1815
16th to endDay
211122235%76%
1815
October1st to 15thDay
21221223476%
1756
16th to endDay
12211335%77%
1760
November1st to 15thDay
112212236%74%
1722
16th to endDay
33221222474%
1620
December1st to 15thDay
4313322346%64%
1620
16th to endDay
431221336%6%63%
1728
January1st to 15thNight
3213323345%65%
2327
16th to endNight
6%313213345%64%
2496
February1st to 15thNight
2212213246%68%
2136
16th to endNight
3313433346%61%
1895
March1st to 15thNight
3212123235%70%
1980
16th to endNight
2111112345%73%
2112
April1st to 15thNight
221321333371%
1901
16th to endNight
1111111385%
1558
May1st to 15thNight
11112345%76%
1484
16th to endNight
1111111384%
1540
June1st to 15thNight
11111122483%
1485
16th to endNight
1111122382%
1485
July1st to 15thNight
211332448%10%55%
1485
16th to endNight
1113336%6%9%14%47%
1575
August1st to 15thNight
22332447%10%57%
1485
16th to endNight
231342446%9%57%
1744
September1st to 15thNight
321432335%8%62%
1815
16th to endNight
11121123480%
1815
October1st to 15thNight
11221223477%
1873
16th to endNight
1111123479%
2112
November1st to 15thNight
2112112235%74%
2135
16th to endNight
3212312135%72%
2340
December1st to 15thNight
5%2232335%5%64%
2340
16th to endNight
4314323446%61%
2496

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
20%2215%27%31%
1612
16th to endDay
21%2315%28%29%
1728
February1st to 15thDay
17%1314%30%32%
1715
16th to endDay
22%2114%31%26%
1579
March1st to 15thDay
19%216%29%41%
1980
16th to endDay
17%227%31%39%
2112
April1st to 15thDay
13%27%36%39%
1886
16th to endDay
9%17%24%57%
2068
May1st to 15thDay
10%26%23%57%
2136
16th to endDay
8%15%24%58%
2224
June1st to 15thDay
9%1215%70%
2145
16th to endDay
10%1311%72%
2145
July1st to 15thDay
24%37%15%17%30%
2006
16th to endDay
35%49%24%18%7%
2130
August1st to 15thDay
26%5%8%16%17%25%
2130
16th to endDay
23%46%19%27%18%
2104
September1st to 15thDay
24%3415%24%27%
1815
16th to endDay
12%26%25%52%
1815
October1st to 15thDay
12%219%25%48%
1756
16th to endDay
11%226%25%51%
1760
November1st to 15thDay
12%2110%30%43%
1722
16th to endDay
16%119%29%41%
1620
December1st to 15thDay
20%3415%29%28%
1620
16th to endDay
21%3420%31%17%
1728
January1st to 15thNight
20%2411%26%33%
2327
16th to endNight
23%2213%27%30%
2496
February1st to 15thNight
17%1415%22%37%
2147
16th to endNight
23%2214%26%29%
1895
March1st to 15thNight
17%18%24%45%
1980
16th to endNight
13%218%32%41%
2112
April1st to 15thNight
17%217%31%39%
1901
16th to endNight
7%17%23%59%
1558
May1st to 15thNight
9%26%24%55%
1485
16th to endNight
9%15%19%63%
1541
June1st to 15thNight
8%1213%72%
1485
16th to endNight
9%1229%74%
1485
July1st to 15thNight
20%410%16%17%30%
1395
16th to endNight
21%6%13%24%23%10%
1467
August1st to 15thNight
20%29%22%18%25%
1476
16th to endNight
21%48%18%27%19%
1744
September1st to 15thNight
20%26%17%22%29%
1815
16th to endNight
9%116%27%52%
1815
October1st to 15thNight
12%1111%24%47%
1873
16th to endNight
10%139%20%55%
2112
November1st to 15thNight
13%28%30%44%
2135
16th to endNight
17%1210%24%44%
2340
December1st to 15thNight
21%3213%27%31%
2340
16th to endNight
23%2416%28%23%
2496

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
10%5%21%37%24%1
90
16th to endDay
7%6%14%32%26%13%
96
February1st to 15thDay
5%6%19%36%28%3
230
16th to endDay
6%10%31%31%18%2
238
March1st to 15thDay
412%24%26%23%8%
270
16th to endDay
112%27%28%23%7%
288
April1st to 15thDay
5%12%28%32%14%7%
239
16th to endDay
312%30%37%11%5%
210
May1st to 15thDay
39%26%37%17%5%
228
16th to endDay
2323%38%25%6%
266
June1st to 15thDay
5%125%34%25%7%
255
16th to endDay
2210%40%28%15%
255
July1st to 15thDay
316%35%37%15%
245
16th to endDay
3225%36%31%
271
August1st to 15thDay
3325%39%26%
255
16th to endDay
1123%49%22%
268
September1st to 15thDay
7%17%33%36%14%
255
16th to endDay
5%119%34%28%10%
255
October1st to 15thDay
35%18%36%27%9%
196
16th to endDay
3232%48%13%
96
November1st to 15thDay
2318%30%35%10%
90
16th to endDay
6%6%13%44%24%4
90
December1st to 15thDay
3310%26%48%7%
90
16th to endDay
8%421%40%22%2
96
January1st to 15thNight
5%211%41%32%7%
720
16th to endNight
9%213%38%29%6%
768
February1st to 15thNight
4313%38%33%5%
704
16th to endNight
45%15%44%24%4
632
March1st to 15thNight
4420%31%30%7%
720
16th to endNight
25%16%36%30%8%
768
April1st to 15thNight
45%23%36%25%4
691
16th to endNight
1423%41%22%5%
507
May1st to 15thNight
15%19%43%26%4
495
16th to endNight
2218%36%34%4
515
June1st to 15thNight
1111%50%32%3
495
16th to endNight
15%42%44%4
495
July1st to 15thNight
4431%47%11%
465
16th to endNight
1124%58%12%
522
August1st to 15thNight
4123%56%13%
494
16th to endNight
3220%55%17%
628
September1st to 15thNight
31423%54%13%
660
16th to endNight
28%33%42%12%
656
October1st to 15thNight
1213%36%37%8%
660
16th to endNight
116%34%42%12%
704
November1st to 15thNight
217%39%39%8%
700
16th to endNight
5%112%34%37%9%
720
December1st to 15thNight
6%210%37%36%5%
720
16th to endNight
5%410%43%29%6%
768
Page generated at 2017-04-09 03:54:10. Version ac04

Copyright 2017 A. Danko


Vekol Road Clear Sky Chart | Charts Home