Elko Observing site
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Elko Observing site clear sky chart from 2005-11-06 to 2024-01-12.

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
51%
23970
23%
74391
17%
23916
59%
23916
29%
45442

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 10thNight
26%
757
24%
2459
10%
757
43%
757
24%
1491
January11th to 20thNight
37%
725
27%
2354
17%
725
51%
725
26%
1398
January21st to endNight
29%
792
26%
2484
12%
792
45%
792
25%
1534
February1st to 10thNight
32%
720
24%
2160
12%
720
45%
720
27%
1355
February11th to 20thNight
31%
703
24%
2098
10%
699
44%
699
28%
1292
February21st to endNight
30%
592
25%
1776
12%
592
42%
592
26%
1120
March1st to 10thNight
39%
720
29%
2064
16%
720
49%
720
34%
1222
March11th to 20thNight
37%
720
23%
1980
11%
720
47%
720
30%
1245
March21st to endNight
39%
792
24%
2178
11%
792
48%
792
32%
1313
April1st to 10thNight
43%
720
25%
1980
17%
720
50%
720
34%
1195
April11th to 20thNight
48%
586
27%
1828
19%
586
57%
586
33%
1052
April21st to endNight
57%
540
33%
1653
23%
540
67%
540
42%
878
May1st to 10thNight
56%
540
27%
1620
18%
540
64%
540
40%
879
May11th to 20thNight
58%
531
17%
1592
12%
531
62%
531
32%
968
May21st to endNight
67%
582
22%
1744
18%
582
69%
582
33%
1051
June1st to 10thNight
62%
540
16%
1620
13%
540
63%
540
25%
1083
June11th to 20thNight
74%
540
18%
1620
16%
540
75%
540
34%
954
June21st to endNight
69%
540
14%
1620
11%
540
70%
540
27%
1049
July1st to 10thNight
74%
525
10%
1575
8%
525
74%
525
23%
1093
July11th to 20thNight
73%
522
10%
1566
9%
522
73%
522
27%
1040
July21st to endNight
75%
591
14%
1672
14%
558
76%
558
30%
1073
August1st to 10thNight
74%
537
14%
1600
14%
534
74%
534
28%
1044
August11th to 20thNight
70%
534
15%
1743
17%
534
70%
534
25%
1122
August21st to endNight
65%
620
16%
2006
18%
620
65%
620
21%
1357
September1st to 10thNight
68%
720
17%
1980
15%
720
68%
720
27%
1335
September11th to 20thNight
64%
720
19%
1980
16%
720
66%
720
28%
1322
September21st to endNight
63%
720
26%
1980
22%
720
66%
720
31%
1269
October1st to 10thNight
59%
720
29%
1980
23%
720
65%
720
38%
1174
October11th to 20thNight
58%
720
34%
2090
27%
720
67%
720
40%
1170
October21st to endNight
55%
792
33%
2376
29%
792
64%
792
38%
1325
November1st to 10thNight
53%
740
29%
2287
24%
740
63%
740
35%
1288
November11th to 20thNight
47%
760
29%
2470
22%
760
58%
760
33%
1361
November21st to endNight
42%
760
27%
2470
19%
760
53%
760
29%
1468
December1st to 10thNight
40%
760
27%
2470
17%
760
54%
760
27%
1475
December11th to 20thNight
38%
759
27%
2902
17%
758
49%
758
23%
1672
December21st to endNight
36%
830
16%
4414
16%
817
45%
817
13%
2775

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%5%35%5%35%5%6%8%42%
74857
Night
11%5%25%5%35%5%6%8%45%
74858
TransparencyDay
40%412%19%19%6%
74580
Night
38%411%18%20%8%
74654
SeeingDay
13%8%21%24%22%12%
13891
Night
13%6%21%32%23%4
23982

By Month

Percentage Cloud Cover SE (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 10thDay
15%6%25%5%34446%46%
1706
11th to 20thDay
12%7%345%34346%49%
1629
21st to endDay
17%7%35%5%2445%6%43%
1870
February1st to 10thDay
15%7%46%5%35%5%46%40%
1800
11th to 20thDay
17%5%35%42445%7%44%
1748
21st to endDay
16%6%35%425%5%5%7%42%
1480
March1st to 10thDay
12%5%25%42445%6%51%
1894
11th to 20thDay
13%5%36%6%345%5%6%44%
1980
21st to endDay
13%5%25%4245%5%7%46%
2178
April1st to 10thDay
11%5%36%5%3445%5%48%
1980
11th to 20thDay
12%6%2443435%8%49%
2095
21st to endDay
6%414435%46%7%56%
2304
May1st to 10thDay
6%4235%35%46%8%54%
2340
11th to 20thDay
8%5%26%5%45%6%7%10%42%
2301
21st to endDay
8%426%6%46%6%8%10%42%
2531
June1st to 10thDay
11%6%36%8%47%6%8%11%31%
2340
11th to 20thDay
6%425%6%46%6%9%11%41%
2340
21st to endDay
6%5%37%7%5%8%6%8%11%35%
2340
July1st to 10thDay
7%5%47%8%6%8%9%9%11%28%
2340
11th to 20thDay
7%5%37%7%6%10%7%8%11%29%
2340
21st to endDay
7%5%36%7%5%8%8%8%12%31%
2547
August1st to 10thDay
8%5%36%8%5%7%7%9%13%29%
2327
11th to 20thDay
9%6%37%7%5%7%7%9%11%29%
2154
21st to endDay
13%7%37%8%47%7%6%9%29%
2332
September1st to 10thDay
9%5%26%6%46%5%7%10%40%
1980
11th to 20thDay
13%5%35%6%45%6%6%8%40%
1980
21st to endDay
13%6%26%5%45%46%6%43%
1980
October1st to 10thDay
12%5%34423446%52%
1980
11th to 20thDay
11%32332435%8%55%
1868
21st to endDay
10%424424446%55%
1980
November1st to 10thDay
11%5%3443345%5%53%
1786
11th to 20thDay
12%5%245%23445%54%
1710
21st to endDay
15%5%25%4245%46%47%
1710
December1st to 10thDay
16%7%35%435%45%6%42%
1710
11th to 20thDay
17%6%345%34346%45%
2153
21st to endDay
19%8%36%5%23335%43%
3124
January1st to 10thNight
15%7%25%43435%6%46%
2459
11th to 20thNight
14%6%35%424446%48%
2354
21st to endNight
17%6%34424345%46%
2484
February1st to 10thNight
14%7%35%43445%6%44%
2160
11th to 20thNight
18%5%24433346%47%
2098
21st to endNight
15%6%26%5%345%5%7%43%
1776
March1st to 10thNight
11%5%34423447%51%
2064
11th to 20thNight
12%5%25%6%3445%8%45%
1980
21st to endNight
10%5%345%3445%7%49%
2178
April1st to 10thNight
11%5%245%35%45%7%50%
1980
11th to 20thNight
11%42443445%9%49%
1828
21st to endNight
6%324435%45%8%57%
1653
May1st to 10thNight
5%4244346%6%8%55%
1620
11th to 20thNight
7%5%345%35%6%7%9%45%
1592
21st to endNight
8%5%26%5%35%5%7%10%43%
1744
June1st to 10thNight
8%6%38%5%46%7%8%10%33%
1620
11th to 20thNight
4425%5%46%6%7%13%44%
1620
21st to endNight
5%446%6%48%7%9%12%34%
1620
July1st to 10thNight
6%5%35%6%5%8%10%10%13%31%
1620
11th to 20thNight
5%5%26%7%5%8%8%9%13%31%
1620
21st to endNight
5%436%6%36%8%10%13%36%
1771
August1st to 10thNight
5%5%25%6%47%8%9%13%36%
1611
11th to 20thNight
9%5%26%6%45%7%9%12%34%
1743
21st to endNight
10%6%27%7%5%7%7%8%10%32%
2006
September1st to 10thNight
9%6%26%5%46%7%7%10%37%
1980
11th to 20thNight
11%6%26%6%35%5%6%7%42%
1980
21st to endNight
9%6%37%6%45%5%6%7%43%
1980
October1st to 10thNight
11%5%145%3435%7%52%
1980
11th to 20thNight
12%424323347%57%
2090
21st to endNight
10%5%25%423446%55%
2376
November1st to 10thNight
11%424433345%56%
2287
11th to 20thNight
13%5%34323346%55%
2470
21st to endNight
13%5%36%434446%48%
2470
December1st to 10thNight
13%5%35%435%45%6%46%
2470
11th to 20thNight
16%5%25%5%23446%49%
3042
21st to endNight
17%9%37%6%35%45%6%37%
4532

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 10thDay
41%26%18%25%7%
1707
11th to 20thDay
38%38%19%24%8%
1629
21st to endDay
43%25%17%25%9%
1870
February1st to 10thDay
46%28%17%18%9%
1800
11th to 20thDay
41%35%17%25%8%
1758
21st to endDay
42%47%17%20%11%
1480
March1st to 10thDay
35%37%19%23%13%
1894
11th to 20thDay
41%412%16%19%9%
1980
21st to endDay
38%311%19%22%6%
2178
April1st to 10thDay
38%49%20%20%10%
1980
11th to 20thDay
34%37%22%23%11%
2095
21st to endDay
28%39%26%27%7%
2304
May1st to 10thDay
30%310%23%27%6%
2340
11th to 20thDay
37%5%17%23%15%4
2305
21st to endDay
37%5%11%26%19%3
2531
June1st to 10thDay
46%5%15%20%12%2
2340
11th to 20thDay
34%7%17%26%15%1
2340
21st to endDay
41%6%19%20%11%2
2340
July1st to 10thDay
44%8%23%18%6%2
2275
11th to 20thDay
45%7%22%18%6%1
2271
21st to endDay
42%8%21%22%7%
2405
August1st to 10thDay
44%8%22%22%5%
2314
11th to 20thDay
46%8%21%18%8%
2154
21st to endDay
51%6%17%15%9%2
2332
September1st to 10thDay
39%6%17%19%15%3
1980
11th to 20thDay
41%5%10%20%18%5%
1980
21st to endDay
41%5%8%20%19%6%
1980
October1st to 10thDay
34%39%20%23%11%
1980
11th to 20thDay
29%37%25%27%10%
1868
21st to endDay
31%36%14%31%17%
1980
November1st to 10thDay
33%37%15%26%16%
1786
11th to 20thDay
34%25%18%26%15%
1710
21st to endDay
39%28%17%23%10%
1710
December1st to 10thDay
43%212%14%20%9%
1710
11th to 20thDay
43%25%16%27%8%
2150
21st to endDay
48%15%17%24%5%
3124
January1st to 10thNight
41%26%19%25%7%
2459
11th to 20thNight
39%26%18%27%8%
2354
21st to endNight
42%2416%26%10%
2484
February1st to 10thNight
41%37%18%21%11%
2160
11th to 20thNight
40%26%17%23%12%
2099
21st to endNight
41%37%17%17%14%
1776
March1st to 10thNight
34%36%19%23%14%
2064
11th to 20thNight
38%412%17%19%10%
1980
21st to endNight
35%311%19%23%9%
2178
April1st to 10thNight
35%310%20%20%13%
1980
11th to 20thNight
34%36%22%23%12%
1828
21st to endNight
26%311%25%25%10%
1653
May1st to 10thNight
28%411%23%25%9%
1620
11th to 20thNight
34%7%18%19%17%4
1593
21st to endNight
35%5%12%25%19%4
1745
June1st to 10thNight
43%7%16%20%13%
1620
11th to 20thNight
31%7%21%27%12%2
1620
21st to endNight
39%8%22%16%12%3
1620
July1st to 10thNight
41%13%23%15%7%2
1575
11th to 20thNight
39%9%30%14%8%
1566
21st to endNight
34%10%26%22%6%1
1672
August1st to 10thNight
36%10%25%23%5%
1600
11th to 20thNight
39%9%24%19%8%1
1743
21st to endNight
45%8%19%16%10%2
2006
September1st to 10thNight
41%8%17%16%14%4
1980
11th to 20thNight
40%7%13%15%19%5%
1980
21st to endNight
39%412%17%22%6%
1980
October1st to 10thNight
33%39%21%23%11%
1980
11th to 20thNight
30%36%21%30%10%
2090
21st to endNight
31%35%17%28%16%
2376
November1st to 10thNight
33%37%14%28%16%
2287
11th to 20thNight
33%26%16%27%16%
2470
21st to endNight
39%26%19%23%11%
2470
December1st to 10thNight
39%310%18%23%7%
2470
11th to 20thNight
39%25%15%29%9%
3044
21st to endNight
50%25%18%21%4
4532

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 10thDay
17%19%46%15%3
270
11th to 20thDay
15%19%39%19%7%2
243
21st to endDay
24%21%41%9%4
264
February1st to 10thDay
21%20%36%18%5%
240
11th to 20thDay
27%17%35%20%2
240
21st to endDay
19%18%44%15%4
198
March1st to 10thDay
14%17%32%25%10%1
334
11th to 20thDay
15%13%36%25%10%1
420
21st to endDay
17%13%34%28%9%
462
April1st to 10thDay
16%16%26%27%13%2
420
11th to 20thDay
14%11%30%26%17%3
412
21st to endDay
10%9%25%31%19%6%
420
May1st to 10thDay
8%11%25%30%20%7%
423
11th to 20thDay
9%218%29%24%17%
447
21st to endDay
11%312%29%28%17%
485
June1st to 10thDay
14%210%29%28%18%
450
11th to 20thDay
8%212%23%25%30%
450
21st to endDay
7%310%27%32%21%
450
July1st to 10thDay
7%26%20%38%28%
445
11th to 20thDay
7%2415%34%38%
444
21st to endDay
6%25%19%38%30%
488
August1st to 10thDay
12%26%21%33%26%
446
11th to 20thDay
10%2418%37%29%
439
21st to endDay
13%37%22%36%20%
495
September1st to 10thDay
11%38%25%34%19%
450
11th to 20thDay
14%210%29%31%13%
450
21st to endDay
15%213%26%30%15%
450
October1st to 10thDay
16%223%29%19%10%
450
11th to 20thDay
10%6%20%32%24%8%
450
21st to endDay
11%8%26%29%23%3
495
November1st to 10thDay
18%5%23%33%17%4
384
11th to 20thDay
13%11%41%25%9%1
270
21st to endDay
13%14%34%26%13%1
270
December1st to 10thDay
21%16%33%23%6%1
270
11th to 20thDay
21%17%36%18%8%
270
21st to endDay
25%14%30%23%7%1
297
January1st to 10thNight
19%11%37%26%6%1
760
11th to 20thNight
16%12%30%31%11%
725
21st to endNight
20%12%34%29%5%
792
February1st to 10thNight
18%10%34%31%7%
720
11th to 20thNight
20%11%35%30%4
703
21st to endNight
19%10%38%30%4
592
March1st to 10thNight
14%10%33%36%8%
720
11th to 20thNight
15%11%30%31%12%1
720
21st to endNight
13%12%31%32%11%
792
April1st to 10thNight
13%9%30%33%15%
720
11th to 20thNight
14%6%28%33%17%2
586
21st to endNight
7%5%26%39%21%1
540
May1st to 10thNight
7%5%25%39%21%2
540
11th to 20thNight
8%321%36%27%6%
531
21st to endNight
10%110%37%36%6%
584
June1st to 10thNight
11%211%35%36%5%
540
11th to 20thNight
427%34%40%12%
540
21st to endNight
7%17%34%42%9%
540
July1st to 10thNight
7%25%28%40%17%
525
11th to 20thNight
7%2419%49%18%
522
21st to endNight
6%1427%48%12%
591
August1st to 10thNight
8%25%26%44%15%
537
11th to 20thNight
10%2325%49%11%
534
21st to endNight
11%36%25%40%15%
620
September1st to 10thNight
11%25%30%43%10%
720
11th to 20thNight
13%27%33%38%6%
720
21st to endNight
12%111%34%38%3
720
October1st to 10thNight
13%218%35%26%6%
720
11th to 20thNight
15%418%34%25%4
720
21st to endNight
12%6%21%35%24%2
792
November1st to 10thNight
14%5%21%37%21%2
740
11th to 20thNight
16%7%26%36%14%1
760
21st to endNight
16%8%30%29%16%1
760
December1st to 10thNight
14%9%31%31%15%1
760
11th to 20thNight
18%8%30%32%11%1
760
21st to endNight
24%10%24%33%9%
836
Page generated at 2024-01-08 22:31:29. Version ac07

Copyright 2024 Attilla Danko


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