Shoshoni
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Shoshoni clear sky chart from 2005-11-05 to 2018-02-13.

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
60%
16738
21%
48828
17%
16700
64%
16700
36%
28592

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
59%
971
16%
2716
12%
970
61%
970
35%
1635
January16th to endNight
58%
851
20%
2723
19%
851
62%
851
31%
1587
February1st to 15thNight
53%
746
16%
2444
15%
746
57%
746
28%
1495
February16th to endNight
51%
632
16%
1995
13%
632
56%
632
30%
1221
March1st to 15thNight
55%
720
18%
2013
11%
720
62%
720
36%
1230
March16th to endNight
51%
755
16%
2099
11%
755
56%
755
31%
1333
April1st to 15thNight
50%
539
15%
1798
12%
539
56%
539
24%
1126
April16th to endNight
46%
540
17%
1707
14%
540
51%
540
25%
1104
May1st to 15thNight
56%
540
17%
1527
14%
540
58%
540
30%
970
May16th to endNight
56%
562
17%
1498
13%
561
58%
561
31%
978
June1st to 15thNight
58%
540
17%
1440
12%
540
61%
540
38%
879
June16th to endNight
69%
540
25%
1440
20%
540
72%
540
57%
728
July1st to 15thNight
79%
510
20%
1360
17%
510
81%
510
56%
709
July16th to endNight
80%
564
28%
1476
26%
531
81%
531
59%
703
August1st to 15thNight
78%
539
28%
1611
26%
536
80%
536
52%
770
August16th to endNight
80%
573
33%
1817
33%
573
82%
573
54%
836
September1st to 15thNight
70%
540
28%
1800
28%
540
77%
540
42%
917
September16th to endNight
71%
669
31%
1981
26%
669
74%
669
49%
995
October1st to 15thNight
56%
720
23%
2160
17%
720
59%
720
30%
1348
October16th to endNight
63%
768
30%
2304
22%
768
69%
768
41%
1261
November1st to 15thNight
59%
929
24%
2547
17%
929
63%
929
39%
1511
November16th to endNight
56%
975
24%
2730
18%
975
62%
975
40%
1592
December1st to 15thNight
59%
975
17%
2730
12%
975
62%
975
32%
1720
December16th to endNight
56%
1040
17%
2912
10%
1040
61%
1040
28%
1944

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
44244245%6%9%51%
49231
Night
45%2442446%8%50%
49005
TransparencyDay
27%7%16%25%16%6%
48910
Night
29%7%17%25%15%5%
48828
SeeingDay
7%5%19%33%26%7%
6415
Night
6%222%47%19%1
16749

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
1426%6%46%7%8%12%38%
1552
16th to endDay
16%25%6%345%7%10%45%
1865
February1st to 15thDay
16%35%7%36%6%7%11%40%
1683
16th to endDay
15%35%6%36%6%6%9%44%
1479
March1st to 15thDay
1425%435%5%8%11%48%
1947
16th to endDay
5%5%35%425%6%6%11%42%
2124
April1st to 15thDay
5%6%25%42446%8%47%
2150
16th to endDay
7%9%26%5%46%5%6%7%37%
2252
May1st to 15thDay
7%6%25%5%245%6%8%45%
2422
16th to endDay
9%414425%6%6%11%42%
2616
June1st to 15thDay
5%3134245%6%9%52%
2520
16th to endDay
11121445%6%69%
2520
July1st to 15thDay
221232446%9%59%
2520
16th to endDay
311222336%8%62%
2588
August1st to 15thDay
321332445%9%58%
2340
16th to endDay
22222345%8%64%
2384
September1st to 15thDay
6%31321335%6%62%
2160
16th to endDay
5%212212347%65%
1977
October1st to 15thDay
8%42432335%6%55%
1800
16th to endDay
332442445%7%55%
1920
November1st to 15thDay
2424425%46%8%55%
1628
16th to endDay
15%246%345%6%8%50%
1560
December1st to 15thDay
25%26%5%37%6%6%11%42%
1560
16th to endDay
26%36%6%5%5%5%8%10%39%
1664
January1st to 15thNight
1425%5%36%6%7%11%44%
2716
16th to endNight
27%46%5%25%36%10%46%
2723
February1st to 15thNight
25%36%7%36%45%9%44%
2433
16th to endNight
27%35%6%346%6%9%43%
1995
March1st to 15thNight
26%26%5%35%5%6%9%47%
2013
16th to endNight
5%6%25%435%6%6%10%42%
2099
April1st to 15thNight
5%6%45%6%35%5%6%8%42%
1798
16th to endNight
9%8%35%5%2445%7%41%
1707
May1st to 15thNight
9%7%1433447%8%44%
1526
16th to endNight
11%4245%3436%10%42%
1497
June1st to 15thNight
7%32442446%9%51%
1440
16th to endNight
211321235%7%67%
1440
July1st to 15thNight
1222325%8%10%60%
1440
16th to endNight
212313446%68%
1577
August1st to 15thNight
2123335%5%11%60%
1620
16th to endNight
231221335%7%66%
1817
September1st to 15thNight
6%31332346%7%58%
1800
16th to endNight
6%213213336%65%
1981
October1st to 15thNight
10%6%24424436%49%
2160
16th to endNight
45%23323347%57%
2304
November1st to 15thNight
23245%345%6%8%52%
2547
16th to endNight
36%245%2445%8%52%
2730
December1st to 15thNight
25%37%5%25%5%7%9%45%
2730
16th to endNight
26%46%6%46%7%7%10%37%
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
31%9%26%25%6%
1553
16th to endDay
31%8%22%26%9%1
1865
February1st to 15thDay
33%10%23%25%6%
1683
16th to endDay
32%7%23%23%10%2
1479
March1st to 15thDay
25%8%22%31%10%
1947
16th to endDay
34%8%19%28%8%
2124
April1st to 15thDay
33%7%21%24%12%1
2150
16th to endDay
41%8%14%23%10%
2252
May1st to 15thDay
35%8%15%27%11%1
2422
16th to endDay
33%9%19%23%12%1
2620
June1st to 15thDay
27%8%14%26%18%4
2520
16th to endDay
13%5%10%24%29%17%
2520
July1st to 15thDay
19%410%24%23%16%
2371
16th to endDay
17%48%20%26%23%
2426
August1st to 15thDay
20%410%22%23%17%
2325
16th to endDay
16%49%22%29%17%
2384
September1st to 15thDay
22%49%24%26%13%
2160
16th to endDay
19%411%28%28%6%
1977
October1st to 15thDay
30%6%15%30%15%2
1800
16th to endDay
25%6%17%30%17%2
1920
November1st to 15thDay
25%6%18%25%21%3
1628
16th to endDay
27%7%23%27%12%1
1560
December1st to 15thDay
33%9%25%23%7%
1560
16th to endDay
36%7%21%25%7%
1664
January1st to 15thNight
29%8%28%25%6%
2716
16th to endNight
33%6%23%26%9%1
2723
February1st to 15thNight
35%8%22%26%7%
2444
16th to endNight
34%8%21%23%10%2
1995
March1st to 15thNight
31%7%20%29%10%
2013
16th to endNight
35%8%21%26%7%
2099
April1st to 15thNight
37%8%16%23%11%1
1798
16th to endNight
40%7%13%25%12%
1707
May1st to 15thNight
34%8%14%26%13%1
1527
16th to endNight
36%8%16%24%11%1
1498
June1st to 15thNight
28%8%15%27%15%4
1440
16th to endNight
16%47%20%31%19%
1440
July1st to 15thNight
15%7%13%23%23%16%
1360
16th to endNight
15%37%20%27%26%
1476
August1st to 15thNight
17%5%12%25%23%15%
1611
16th to endNight
16%410%20%30%17%
1817
September1st to 15thNight
22%6%9%20%28%13%
1800
16th to endNight
21%312%24%30%8%
1981
October1st to 15thNight
36%6%11%25%15%5%
2160
16th to endNight
27%414%30%18%4
2304
November1st to 15thNight
27%7%16%28%16%3
2547
16th to endNight
28%6%19%30%13%1
2730
December1st to 15thNight
33%9%21%26%8%
2730
16th to endNight
38%8%20%24%6%1
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
219%51%24%10%
135
16th to endDay
6%452%27%8%
144
February1st to 15thDay
3216%61%13%1
126
16th to endDay
3322%40%23%6%
81
March1st to 15thDay
410%29%35%17%2
237
16th to endDay
11%14%31%29%13%
288
April1st to 15thDay
9%14%32%26%15%1
269
16th to endDay
17%17%29%19%13%2
270
May1st to 15thDay
14%8%19%29%23%5%
379
16th to endDay
10%7%20%27%26%7%
517
June1st to 15thDay
6%6%24%26%27%9%
495
16th to endDay
2320%37%31%5%
495
July1st to 15thDay
4212%31%37%10%
475
16th to endDay
3214%35%36%7%
447
August1st to 15thDay
6%216%28%37%9%
315
16th to endDay
3412%27%31%20%
332
September1st to 15thDay
7%320%30%23%14%
315
16th to endDay
10%5%17%27%26%11%
267
October1st to 15thDay
11%217%34%27%7%
135
16th to endDay
3414%44%24%8%
144
November1st to 15thDay
3414%36%25%14%
135
16th to endDay
10%5%14%41%26%1
135
December1st to 15thDay
37%65%20%2
135
16th to endDay
6%7%63%15%6%
144
January1st to 15thNight
3324%52%15%1
975
16th to endNight
5%221%52%15%1
851
February1st to 15thNight
4124%52%15%1
752
16th to endNight
4230%47%12%1
632
March1st to 15thNight
5%127%46%17%
720
16th to endNight
8%329%45%12%
755
April1st to 15thNight
8%429%45%11%
539
16th to endNight
12%5%27%38%14%
540
May1st to 15thNight
12%7%20%36%22%1
540
16th to endNight
13%320%37%24%1
563
June1st to 15thNight
8%324%39%22%1
540
16th to endNight
3220%50%22%
540
July1st to 15thNight
213%49%32%
510
16th to endNight
212%52%30%1
564
August1st to 15thNight
310%48%35%1
539
16th to endNight
3110%43%38%2
573
September1st to 15thNight
7%214%44%29%1
540
16th to endNight
7%214%38%32%4
669
October1st to 15thNight
13%221%40%20%2
720
16th to endNight
6%222%45%20%1
768
November1st to 15thNight
4325%47%17%1
929
16th to endNight
5%327%50%12%
975
December1st to 15thNight
5%222%56%12%
975
16th to endNight
4322%56%12%
1040
Page generated at 2018-02-13 18:45:59. Version ac04

Copyright 2018 A. Danko


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