Summer Village of Yellowstone
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Summer Village of Yellowstone clear sky chart from 2005-11-05 to

2017-09-12
.

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
41%
15116
10%
46415
7%
15092
44%
15092
17%
33576

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
30%
896
7%
2689
4%
896
33%
896
13%
2094
January16th to endNight
29%
886
15%
2806
8%
886
37%
886
16%
2026
February1st to 15thNight
38%
698
9%
2462
7%
698
42%
698
13%
1780
February16th to endNight
46%
632
11%
2000
11%
632
49%
632
17%
1462
March1st to 15thNight
37%
720
14%
2132
10%
720
42%
720
18%
1570
March16th to endNight
39%
768
10%
2065
5%
768
42%
768
16%
1608
April1st to 15thNight
38%
614
10%
1694
6%
614
41%
614
18%
1281
April16th to endNight
41%
528
11%
1608
9%
528
45%
528
17%
1168
May1st to 15thNight
45%
359
7%
1301
6%
359
47%
359
17%
887
May16th to endNight
40%
374
0%
1309
0%
374
40%
374
14%
956
June1st to 15thNight
45%
360
0%
1185
0%
360
45%
360
13%
897
June16th to endNight
53%
360
0%
1080
0%
360
53%
360
18%
792
July1st to 15thNight
60%
340
0%
1075
0%
340
60%
340
24%
710
July16th to endNight
57%
376
2%
1239
1%
354
58%
354
20%
802
August1st to 15thNight
64%
360
6%
1405
7%
358
65%
358
19%
892
August16th to endNight
55%
559
13%
1705
11%
559
57%
559
24%
1116
September1st to 15thNight
59%
634
15%
1738
11%
634
60%
634
32%
1118
September16th to endNight
51%
656
19%
1815
12%
656
56%
656
32%
1148
October1st to 15thNight
42%
660
14%
1979
10%
660
46%
660
20%
1407
October16th to endNight
40%
704
14%
2288
10%
704
46%
704
18%
1608
November1st to 15thNight
31%
862
13%
2500
9%
862
36%
862
15%
1907
November16th to endNight
31%
900
10%
2700
5%
900
36%
900
14%
2067
December1st to 15thNight
31%
900
11%
2700
7%
900
35%
900
14%
2073
December16th to endNight
37%
970
11%
2940
6%
970
41%
970
16%
2207

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%9%47%6%45%5%6%7%31%
48268
Night
10%10%48%7%35%5%5%7%30%
46557
TransparencyDay
48%9%17%19%5%
47913
Night
50%8%14%18%6%
46418
SeeingDay
15%5%22%30%20%6%
6442
Night
14%426%34%17%2
15129

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
7%12%5%12%8%345%5%7%26%
1241
16th to endDay
7%14%5%9%7%45%46%5%29%
1428
February1st to 15thDay
9%10%5%8%8%46%5%7%7%26%
1401
16th to endDay
5%12%7%10%9%5%5%7%6%6%22%
1473
March1st to 15thDay
7%13%7%8%9%45%6%5%7%24%
1828
16th to endDay
11%14%5%7%6%36%6%6%7%23%
2155
April1st to 15thDay
11%11%47%6%45%5%6%6%29%
2254
16th to endDay
13%12%37%6%45%6%5%8%27%
2349
May1st to 15thDay
9%8%36%7%46%6%6%7%33%
2649
16th to endDay
18%6%35%5%35%46%8%31%
2802
June1st to 15thDay
16%8%47%6%45%6%6%6%26%
2772
16th to endDay
13%6%36%7%36%6%6%8%32%
2880
July1st to 15thDay
12%5%15%5%35%6%7%9%38%
2820
16th to endDay
9%425%5%36%5%7%9%39%
2846
August1st to 15thDay
9%5%25%5%35%6%8%11%37%
2547
16th to endDay
8%5%25%6%46%6%7%8%38%
2497
September1st to 15thDay
12%6%26%5%3445%7%40%
2138
16th to endDay
10%6%26%5%2445%9%42%
1815
October1st to 15thDay
14%10%37%6%2345%6%35%
1650
16th to endDay
9%10%5%7%6%346%6%6%32%
1584
November1st to 15thDay
11%13%5%7%7%345%5%8%27%
1346
16th to endDay
6%11%5%10%8%5%6%336%31%
1260
December1st to 15thDay
6%13%6%12%8%6%7%5%46%20%
1260
16th to endDay
6%11%6%10%9%48%6%47%23%
1273
January1st to 15thNight
7%14%6%11%8%46%5%5%7%23%
2689
16th to endNight
7%11%5%9%7%45%5%5%7%30%
2806
February1st to 15thNight
6%9%5%12%8%45%45%6%28%
2450
16th to endNight
7%12%6%7%7%36%6%5%8%27%
2000
March1st to 15thNight
8%9%5%8%8%46%6%6%7%27%
2132
16th to endNight
9%12%6%10%6%46%6%5%9%22%
2064
April1st to 15thNight
11%10%48%8%47%5%5%7%27%
1694
16th to endNight
14%10%36%6%45%5%6%7%29%
1608
May1st to 15thNight
9%9%48%7%35%5%6%8%31%
1301
16th to endNight
20%8%46%5%446%5%5%27%
1309
June1st to 15thNight
15%9%38%6%47%6%5%8%23%
1185
16th to endNight
11%5%38%6%47%8%7%10%27%
1080
July1st to 15thNight
10%5%25%435%5%8%10%37%
1139
16th to endNight
11%325%5%35%6%8%10%36%
1323
August1st to 15thNight
8%5%246%35%7%7%9%38%
1412
16th to endNight
10%5%26%5%25%7%6%10%37%
1705
September1st to 15thNight
10%6%25%42435%8%45%
1738
16th to endNight
9%6%1442346%9%46%
1815
October1st to 15thNight
13%10%46%5%35%45%7%34%
1979
16th to endNight
9%9%37%7%35%6%7%7%32%
2288
November1st to 15thNight
13%12%5%9%7%345%45%27%
2500
16th to endNight
8%12%6%9%8%5%5%446%27%
2700
December1st to 15thNight
10%14%5%10%7%445%5%7%25%
2700
16th to endNight
5%13%6%10%8%46%5%5%7%26%
2940

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
56%8%15%12%5%
1241
16th to endDay
53%6%14%16%7%1
1428
February1st to 15thDay
53%7%17%14%5%
1401
16th to endDay
58%8%13%14%5%
1473
March1st to 15thDay
56%8%13%17%4
1828
16th to endDay
56%8%14%16%4
2156
April1st to 15thDay
51%8%15%18%6%
2254
16th to endDay
53%7%14%17%6%1
2349
May1st to 15thDay
46%7%14%21%9%
2649
16th to endDay
49%7%13%19%8%
2807
June1st to 15thDay
55%8%17%15%3
2772
16th to endDay
46%10%18%19%4
2880
July1st to 15thDay
40%10%20%23%4
2656
16th to endDay
37%12%27%20%2
2667
August1st to 15thDay
37%13%28%18%2
2529
16th to endDay
38%11%24%19%5%
2497
September1st to 15thDay
41%8%19%22%6%1
2138
16th to endDay
37%8%17%27%6%1
1815
October1st to 15thDay
48%8%13%24%4
1650
16th to endDay
48%9%12%25%3
1584
November1st to 15thDay
54%7%15%17%5%
1346
16th to endDay
54%8%13%16%5%1
1260
December1st to 15thDay
64%6%10%15%2
1260
16th to endDay
57%7%12%15%6%
1273
January1st to 15thNight
59%6%13%13%41
2689
16th to endNight
52%7%13%16%8%1
2806
February1st to 15thNight
54%7%14%15%6%
2462
16th to endNight
51%8%13%16%8%1
2000
March1st to 15thNight
51%8%13%19%6%
2132
16th to endNight
56%7%12%16%6%
2067
April1st to 15thNight
55%6%13%16%6%1
1694
16th to endNight
51%7%11%18%9%
1608
May1st to 15thNight
47%8%10%19%12%1
1302
16th to endNight
55%7%11%15%8%2
1309
June1st to 15thNight
55%9%13%16%4
1185
16th to endNight
47%12%17%19%3
1080
July1st to 15thNight
38%11%23%21%5%
1075
16th to endNight
39%12%25%20%2
1239
August1st to 15thNight
38%13%24%21%2
1405
16th to endNight
38%10%18%25%6%
1705
September1st to 15thNight
36%6%17%28%9%1
1738
16th to endNight
33%8%15%28%10%2
1815
October1st to 15thNight
49%7%13%21%7%
1979
16th to endNight
46%10%16%22%4
2288
November1st to 15thNight
57%6%10%19%5%
2500
16th to endNight
57%7%14%14%5%1
2700
December1st to 15thNight
58%6%14%15%5%
2700
16th to endNight
55%6%14%16%6%
2940

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%23%26%26%8%
60
16th to endDay
7%317%35%25%10%
64
February1st to 15thDay
16%324%42%13%
61
16th to endDay
15%5%22%31%20%5%
132
March1st to 15thDay
16%5%30%31%13%2
270
16th to endDay
17%427%27%21%1
288
April1st to 15thDay
15%9%29%33%11%1
269
16th to endDay
20%7%24%25%16%4
270
May1st to 15thDay
12%7%22%32%20%4
426
16th to endDay
19%418%30%19%6%
517
June1st to 15thDay
19%6%21%28%17%5%
567
16th to endDay
14%420%28%23%8%
675
July1st to 15thDay
11%218%33%27%6%
590
16th to endDay
12%219%31%26%7%
515
August1st to 15thDay
10%214%28%24%18%
342
16th to endDay
12%5%21%35%22%2
332
September1st to 15thDay
17%5%21%29%20%6%
300
16th to endDay
11%10%25%31%16%4
255
October1st to 15thDay
26%5%22%24%15%6%
150
16th to endDay
19%223%31%19%3
96
November1st to 15thDay
27%31%27%11%1
79
16th to endDay
10%10%28%30%11%10%
60
December1st to 15thDay
16%33%21%23%5%
60
16th to endDay
6%421%32%26%7%
64
January1st to 15thNight
13%5%31%32%13%2
901
16th to endNight
12%7%34%30%12%1
886
February1st to 15thNight
11%5%25%35%18%2
704
16th to endNight
12%325%34%19%3
632
March1st to 15thNight
12%430%35%14%2
720
16th to endNight
14%326%36%16%2
768
April1st to 15thNight
14%5%26%35%15%1
614
16th to endNight
18%5%24%35%15%1
528
May1st to 15thNight
12%424%39%16%1
360
16th to endNight
23%323%29%19%1
375
June1st to 15thNight
21%418%36%16%3
360
16th to endNight
13%218%37%25%3
360
July1st to 15thNight
13%214%44%24%1
340
16th to endNight
11%217%40%25%2
376
August1st to 15thNight
9%215%30%35%6%
360
16th to endNight
13%220%38%23%1
559
September1st to 15thNight
14%215%39%25%2
634
16th to endNight
13%425%35%18%2
656
October1st to 15thNight
18%324%34%16%1
660
16th to endNight
15%5%30%35%12%1
704
November1st to 15thNight
18%5%32%30%11%2
862
16th to endNight
14%6%32%32%11%2
900
December1st to 15thNight
17%6%29%30%13%2
900
16th to endNight
11%5%27%33%17%4
970
Page generated at 2017-09-13 05:39:04. Version ac04

Copyright 2017 A. Danko


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