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Green River State Wildlife Area
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Green River State Wildlife Area 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
38%
15953
19%
46786
11%
15910
45%
15910
26%
30496

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
22%
900
14%
2506
5%
895
31%
895
20%
1772
January16th to endNight
22%
960
13%
2598
5%
960
29%
960
18%
1906
February1st to 15thNight
24%
844
15%
2256
4%
844
32%
844
21%
1595
February16th to endNight
27%
631
19%
1893
8%
631
36%
631
20%
1283
March1st to 15thNight
29%
708
15%
2148
8%
708
35%
708
21%
1457
March16th to endNight
31%
576
14%
2004
9%
576
38%
576
18%
1372
April1st to 15thNight
29%
539
16%
1797
11%
539
38%
539
21%
1180
April16th to endNight
34%
540
19%
1787
14%
540
43%
540
22%
1190
May1st to 15thNight
37%
540
17%
1539
10%
540
44%
540
25%
1037
May16th to endNight
47%
563
19%
1497
10%
561
54%
561
32%
965
June1st to 15thNight
57%
540
18%
1440
12%
540
61%
540
38%
875
June16th to endNight
52%
540
18%
1440
10%
540
56%
540
34%
914
July1st to 15thNight
66%
510
18%
1360
12%
510
68%
510
42%
796
July16th to endNight
70%
564
23%
1417
18%
531
72%
531
44%
817
August1st to 15thNight
73%
539
23%
1599
23%
536
75%
536
43%
864
August16th to endNight
68%
573
22%
1910
23%
573
72%
573
35%
1037
September1st to 15thNight
65%
525
29%
1750
30%
525
70%
525
39%
911
September16th to endNight
56%
627
26%
1785
18%
627
62%
627
36%
1042
October1st to 15thNight
46%
660
28%
1952
20%
660
54%
660
35%
1144
October16th to endNight
31%
704
19%
2194
11%
704
40%
704
23%
1396
November1st to 15thNight
34%
700
25%
2276
16%
700
46%
700
29%
1336
November16th to endNight
26%
810
18%
2430
10%
810
36%
810
21%
1628
December1st to 15thNight
22%
900
14%
2520
4%
900
30%
900
18%
1850
December16th to endNight
19%
960
12%
2688
4%
960
26%
960
13%
2129

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
13%8%36%5%3445%7%37%
47847
Night
13%7%35%424446%40%
46955
Cloud CoverDay
14%7%35%5%3445%7%37%
47855
Night
14%7%35%424446%41%
46960
TransparencyDay
45%412%23%12%1
47533
Night
43%311%24%14%2
46787
SeeingDay
15%6%24%27%18%6%
5960
Night
17%7%28%31%12%1
15956

By Month

Percentage Cloud Cover NE (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
13%13%48%6%35%5%47%25%
1432
16th to endDay
14%14%6%10%6%25%45%5%25%
1624
February1st to 15thDay
14%14%48%5%25%445%29%
1606
16th to endDay
13%10%47%6%45%35%7%31%
1580
March1st to 15thDay
16%11%35%6%2435%6%33%
1811
16th to endDay
17%9%5%6%5%45%45%8%29%
2220
April1st to 15thDay
17%10%47%5%2435%6%33%
2151
16th to endDay
20%9%25%5%335%46%33%
2172
May1st to 15thDay
18%8%47%5%35%45%7%29%
2410
16th to endDay
14%6%25%6%35%46%7%36%
2617
June1st to 15thDay
11%5%24435%5%6%8%42%
2520
16th to endDay
9%5%25%5%35%5%6%10%39%
2520
July1st to 15thDay
6%5%25%425%6%6%9%45%
2520
16th to endDay
6%425%5%35%6%6%10%43%
2655
August1st to 15thDay
5%5%15%5%35%6%8%9%43%
2349
16th to endDay
10%5%23435%5%5%8%44%
2292
September1st to 15thDay
13%313424447%49%
2097
16th to endDay
9%5%35%43445%7%46%
1834
October1st to 15thDay
16%5%24323345%46%
1675
16th to endDay
18%8%25%424346%39%
1677
November1st to 15thDay
13%9%345%2445%6%41%
1582
16th to endDay
17%11%5%6%423335%37%
1527
December1st to 15thDay
18%13%47%6%3434427%
1440
16th to endDay
19%14%5%7%7%23446%22%
1536
January1st to 15thNight
14%10%47%5%3435%5%34%
2506
16th to endNight
11%11%6%9%6%34446%29%
2598
February1st to 15thNight
14%10%5%7%424436%36%
2254
16th to endNight
15%10%47%414435%38%
1893
March1st to 15thNight
16%9%35%434445%37%
2135
16th to endNight
17%8%36%6%35%45%7%31%
2004
April1st to 15thNight
17%9%44434346%38%
1797
16th to endNight
19%7%35%42346%6%36%
1787
May1st to 15thNight
16%7%25%4245%6%8%35%
1539
16th to endNight
10%5%25%5%245%7%9%42%
1496
June1st to 15thNight
10%32442445%6%50%
1440
16th to endNight
8%3246%36%6%5%9%43%
1440
July1st to 15thNight
6%414334447%54%
1440
16th to endNight
42244346%7%10%48%
1513
August1st to 15thNight
5%32343345%8%55%
1608
16th to endNight
8%42443335%8%51%
1910
September1st to 15thNight
10%313312346%58%
1750
16th to endNight
7%4244247%5%7%48%
1785
October1st to 15thNight
10%6%24423345%52%
1952
16th to endNight
17%8%34323346%41%
2194
November1st to 15thNight
12%7%23413337%48%
2276
16th to endNight
17%8%35%423346%38%
2430
December1st to 15thNight
19%12%47%423345%31%
2520
16th to endNight
22%13%5%8%5%35%33423%
2688

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 15thDay
14%12%5%8%6%36%5%46%26%
1432
16th to endDay
14%15%5%9%6%245%35%26%
1624
February1st to 15thDay
14%14%48%5%35%445%29%
1606
16th to endDay
13%10%5%7%5%45%346%32%
1580
March1st to 15thDay
16%11%45%6%34346%33%
1821
16th to endDay
17%9%5%6%5%3445%7%30%
2218
April1st to 15thDay
18%10%5%6%424445%33%
2151
16th to endDay
21%8%25%5%24446%33%
2172
May1st to 15thDay
19%7%37%5%345%47%30%
2410
16th to endDay
14%6%25%5%35%45%8%36%
2617
June1st to 15thDay
12%4245%35%5%5%8%42%
2520
16th to endDay
10%425%5%35%5%7%10%40%
2520
July1st to 15thDay
7%4245%25%6%6%9%45%
2520
16th to endDay
7%3245%35%5%6%10%43%
2655
August1st to 15thDay
6%4245%35%5%7%10%44%
2349
16th to endDay
11%5%144345%5%8%45%
2292
September1st to 15thDay
14%31432435%8%49%
2097
16th to endDay
9%5%26%42445%8%46%
1834
October1st to 15thDay
16%6%24322445%47%
1675
16th to endDay
18%8%245%23345%39%
1677
November1st to 15thDay
13%8%34424446%41%
1582
16th to endDay
18%10%5%5%423325%37%
1527
December1st to 15thDay
18%14%48%5%34345%27%
1440
16th to endDay
19%14%7%6%6%33446%23%
1536
January1st to 15thNight
14%11%5%6%6%34345%34%
2506
16th to endNight
12%11%7%9%6%35%45%6%29%
2598
February1st to 15thNight
14%11%5%6%5%23435%37%
2247
16th to endNight
15%10%37%414336%38%
1893
March1st to 15thNight
17%9%35%424445%38%
2148
16th to endNight
17%9%45%6%35%45%7%31%
2004
April1st to 15thNight
18%8%44334336%38%
1797
16th to endNight
19%7%35%42345%6%37%
1787
May1st to 15thNight
16%6%25%425%46%7%36%
1538
16th to endNight
10%5%25%4145%7%9%43%
1496
June1st to 15thNight
10%424424447%49%
1440
16th to endNight
9%2245%36%5%7%8%44%
1440
July1st to 15thNight
7%31432445%7%54%
1440
16th to endNight
4214425%5%8%10%49%
1513
August1st to 15thNight
5%32343245%8%55%
1608
16th to endNight
9%324423447%51%
1910
September1st to 15thNight
10%323313245%58%
1750
16th to endNight
8%4243246%5%7%49%
1785
October1st to 15thNight
11%434423345%52%
1952
16th to endNight
18%8%24323346%41%
2194
November1st to 15thNight
12%7%23323346%49%
2276
16th to endNight
17%7%45%423346%38%
2430
December1st to 15thNight
19%12%47%42334431%
2520
16th to endNight
22%13%5%8%5%3433424%
2688

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
57%412%15%9%
1433
16th to endDay
60%312%16%7%
1624
February1st to 15thDay
56%212%20%6%1
1608
16th to endDay
52%412%21%7%
1580
March1st to 15thDay
51%414%21%7%
1821
16th to endDay
52%315%22%5%
2220
April1st to 15thDay
51%311%24%8%
2151
16th to endDay
50%411%19%12%1
2172
May1st to 15thDay
52%5%12%22%7%
2410
16th to endDay
45%5%12%21%14%
2621
June1st to 15thDay
37%313%28%15%
2520
16th to endDay
37%6%12%25%16%2
2520
July1st to 15thDay
33%5%14%28%15%2
2371
16th to endDay
32%5%18%26%14%2
2488
August1st to 15thDay
32%6%15%26%16%2
2334
16th to endDay
35%6%11%28%16%2
2292
September1st to 15thDay
34%49%27%21%3
2097
16th to endDay
35%310%30%18%1
1834
October1st to 15thDay
39%39%30%16%
1675
16th to endDay
46%213%24%10%2
1677
November1st to 15thDay
42%311%26%13%2
1582
16th to endDay
50%216%23%6%
1527
December1st to 15thDay
59%313%16%7%
1440
16th to endDay
62%412%11%8%
1536
January1st to 15thNight
51%313%19%12%
2506
16th to endNight
54%315%17%9%
2598
February1st to 15thNight
49%311%22%11%
2256
16th to endNight
48%312%24%9%1
1893
March1st to 15thNight
48%413%21%10%2
2148
16th to endNight
51%313%20%9%1
2004
April1st to 15thNight
47%29%23%14%2
1797
16th to endNight
47%49%23%10%4
1787
May1st to 15thNight
44%413%23%12%
1539
16th to endNight
36%6%13%23%17%2
1498
June1st to 15thNight
33%312%27%19%2
1440
16th to endNight
35%6%12%22%19%4
1440
July1st to 15thNight
30%212%31%19%2
1360
16th to endNight
25%6%15%29%18%4
1417
August1st to 15thNight
25%414%33%18%3
1599
16th to endNight
30%412%28%19%4
1910
September1st to 15thNight
28%29%28%27%4
1750
16th to endNight
31%49%31%19%3
1785
October1st to 15thNight
33%39%27%22%2
1952
16th to endNight
44%39%26%14%1
2194
November1st to 15thNight
36%310%26%18%4
2276
16th to endNight
47%311%25%11%
2430
December1st to 15thNight
55%211%21%8%
2520
16th to endNight
64%29%15%6%
2688

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
28%8%36%21%4
90
16th to endDay
18%12%39%14%13%1
96
February1st to 15thDay
17%13%47%13%7%
90
16th to endDay
18%18%32%17%11%2
81
March1st to 15thDay
31%17%31%15%31
90
16th to endDay
24%11%26%26%8%1
204
April1st to 15thDay
21%11%30%25%9%1
270
16th to endDay
24%10%25%24%12%4
270
May1st to 15thDay
20%10%29%25%11%2
367
16th to endDay
15%8%28%24%17%5%
517
June1st to 15thDay
10%425%33%20%4
495
16th to endDay
12%5%31%28%16%6%
495
July1st to 15thDay
12%219%30%23%11%
475
16th to endDay
8%118%30%30%11%
515
August1st to 15thDay
6%215%33%30%11%
448
16th to endDay
9%312%32%28%12%
332
September1st to 15thDay
13%214%34%26%9%
294
16th to endDay
8%5%20%31%28%5%
254
October1st to 15thDay
13%8%23%28%20%4
115
16th to endDay
25%8%37%21%7%
96
November1st to 15thDay
6%7%26%32%18%7%
90
16th to endDay
40%12%25%17%4
90
December1st to 15thDay
21%12%31%27%6%1
90
16th to endDay
28%19%41%8%2
96
January1st to 15thNight
20%12%38%23%5%
900
16th to endNight
18%11%36%28%5%
960
February1st to 15thNight
20%9%36%27%5%
847
16th to endNight
19%10%36%27%6%
631
March1st to 15thNight
23%8%32%28%7%
708
16th to endNight
21%7%34%27%8%1
576
April1st to 15thNight
23%10%32%27%5%
539
16th to endNight
23%8%28%29%9%
540
May1st to 15thNight
20%6%29%34%8%
540
16th to endNight
12%428%38%14%
563
June1st to 15thNight
10%321%49%13%
540
16th to endNight
9%329%42%15%
540
July1st to 15thNight
10%115%41%28%2
510
16th to endNight
5%114%45%30%3
564
August1st to 15thNight
5%18%46%32%5%
539
16th to endNight
10%112%39%32%3
573
September1st to 15thNight
10%314%39%27%4
525
16th to endNight
9%5%21%37%22%3
627
October1st to 15thNight
13%6%27%32%18%1
660
16th to endNight
22%10%32%25%9%
704
November1st to 15thNight
16%7%36%27%10%1
700
16th to endNight
22%11%33%25%6%
810
December1st to 15thNight
26%10%32%24%6%
900
16th to endNight
28%11%31%23%4
960
Page generated at 2017-09-11 18:35:17. Version ac04

Copyright 2017 A. Danko


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