Glendo State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Glendo State Park clear sky chart from 2005-11-05 to 2017-08-12.

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
46%
15941
23%
46491
14%
15900
54%
15900
36%
26778

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
38%
899
24%
2506
13%
895
47%
895
32%
1502
January16th to endNight
35%
885
26%
2613
13%
885
48%
885
34%
1497
February1st to 15thNight
40%
699
19%
2281
13%
699
48%
699
29%
1335
February16th to endNight
35%
632
22%
1894
10%
632
46%
632
31%
1128
March1st to 15thNight
42%
720
23%
2133
11%
720
52%
720
35%
1231
March16th to endNight
39%
670
21%
2014
12%
670
48%
670
30%
1231
April1st to 15thNight
39%
539
18%
1798
13%
539
49%
539
25%
1102
April16th to endNight
35%
540
16%
1788
11%
540
43%
540
22%
1143
May1st to 15thNight
44%
540
20%
1497
13%
540
49%
540
31%
939
May16th to endNight
48%
562
17%
1498
9%
561
53%
561
31%
976
June1st to 15thNight
47%
540
17%
1440
8%
540
52%
540
40%
848
June16th to endNight
57%
540
24%
1440
14%
540
62%
540
58%
724
July1st to 15thNight
62%
510
20%
1360
13%
510
66%
510
47%
758
July16th to endNight
68%
564
25%
1416
18%
531
70%
531
51%
759
August1st to 15thNight
65%
527
25%
1531
19%
524
70%
524
46%
791
August16th to endNight
66%
525
27%
1750
27%
525
72%
525
41%
882
September1st to 15thNight
56%
495
29%
1650
25%
495
66%
495
37%
873
September16th to endNight
61%
492
35%
1772
32%
492
69%
492
46%
806
October1st to 15thNight
48%
654
25%
1974
17%
654
54%
654
33%
1184
October16th to endNight
48%
773
30%
2181
15%
773
58%
773
42%
1222
November1st to 15thNight
47%
875
28%
2275
15%
875
53%
875
43%
1308
November16th to endNight
45%
900
30%
2472
14%
900
56%
900
43%
1372
December1st to 15thNight
33%
900
19%
2520
10%
900
42%
900
32%
1531
December16th to endNight
38%
960
22%
2688
11%
960
48%
960
32%
1636

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
6%5%2342446%8%51%
47492
Night
5%5%2442445%7%53%
46657
Cloud CoverDay
5%5%244245%6%8%50%
47502
Night
5%5%2442445%7%53%
46662
TransparencyDay
29%6%14%25%17%6%
47175
Night
29%6%14%26%17%5%
46491
SeeingDay
9%8%29%29%18%4
5842
Night
7%8%33%37%12%
15948

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
25%24425%5%6%10%51%
1432
16th to endDay
35%25%32446%7%54%
1620
February1st to 15thDay
29%34425%5%6%9%45%
1581
16th to endDay
48%35%5%35%5%5%7%46%
1580
March1st to 15thDay
37%2442246%7%54%
1817
16th to endDay
7%5%25%6%2445%8%47%
2208
April1st to 15thDay
9%6%25%42346%9%46%
2150
16th to endDay
12%8%25%5%36%5%47%37%
2172
May1st to 15thDay
11%7%35%5%25%45%7%42%
2452
16th to endDay
11%5%245%46%6%7%8%37%
2616
June1st to 15thDay
8%422425%6%6%10%47%
2520
16th to endDay
22122347%9%62%
2520
July1st to 15thDay
4213335%47%8%54%
2520
16th to endDay
4313335%5%7%8%53%
2656
August1st to 15thDay
42135%35%6%7%9%51%
2333
16th to endDay
431231445%8%58%
2100
September1st to 15thDay
9%413323446%56%
1980
16th to endDay
5%212222347%65%
1857
October1st to 15thDay
8%5%13425%447%52%
1653
16th to endDay
45%2332345%8%57%
1680
November1st to 15thDay
44233235%5%7%56%
1583
16th to endDay
34244235%5%9%54%
1486
December1st to 15thDay
36%444345%5%9%47%
1440
16th to endDay
47%35%31445%8%50%
1536
January1st to 15thNight
3426%43446%7%51%
2506
16th to endNight
35%25%43445%6%54%
2613
February1st to 15thNight
36%245%35%46%8%48%
2277
16th to endNight
38%35%4245%5%6%49%
1894
March1st to 15thNight
45%24435%45%7%52%
2120
16th to endNight
7%6%36%5%2445%7%46%
2014
April1st to 15thNight
9%5%35%5%3445%7%45%
1798
16th to endNight
14%6%35%5%25%336%43%
1788
May1st to 15thNight
10%5%14434447%48%
1497
16th to endNight
10%414426%5%6%8%46%
1497
June1st to 15thNight
7%312235%45%9%52%
1440
16th to endNight
22221335%7%67%
1440
July1st to 15thNight
5%2123145%6%8%57%
1440
16th to endNight
411232445%8%61%
1512
August1st to 15thNight
22143235%7%9%56%
1539
16th to endNight
432342445%6%58%
1750
September1st to 15thNight
7%5%23422436%56%
1650
16th to endNight
5%212323235%67%
1772
October1st to 15thNight
11%5%24323446%51%
1974
16th to endNight
5%5%1332335%6%57%
2181
November1st to 15thNight
44134235%5%6%57%
2275
16th to endNight
25%2332435%8%56%
2472
December1st to 15thNight
46%35%42435%8%50%
2520
16th to endNight
37%2443445%8%49%
2688

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
15%24435%5%5%10%51%
1432
16th to endDay
35%2431445%8%53%
1620
February1st to 15thDay
210%34425%5%6%9%45%
1581
16th to endDay
47%35%5%26%5%5%7%46%
1580
March1st to 15thDay
37%2442345%7%54%
1827
16th to endDay
6%5%246%2446%8%47%
2208
April1st to 15thDay
8%6%35%42345%8%46%
2150
16th to endDay
12%8%25%5%36%5%5%7%37%
2172
May1st to 15thDay
11%6%35%5%25%46%7%41%
2452
16th to endDay
10%5%25%5%36%6%7%8%37%
2616
June1st to 15thDay
8%413425%6%6%10%47%
2520
16th to endDay
221122347%9%62%
2520
July1st to 15thDay
4213325%5%7%8%53%
2520
16th to endDay
4213325%6%7%9%53%
2656
August1st to 15thDay
4213435%6%8%9%51%
2333
16th to endDay
43332446%8%58%
2100
September1st to 15thDay
9%41332335%6%55%
1980
16th to endDay
5%212222347%66%
1857
October1st to 15thDay
8%5%23324446%52%
1653
16th to endDay
441332345%8%57%
1680
November1st to 15thDay
342333346%7%56%
1583
16th to endDay
33244235%6%9%54%
1486
December1st to 15thDay
37%444245%6%9%46%
1440
16th to endDay
47%3442445%8%50%
1536
January1st to 15thNight
2425%5%35%5%6%7%50%
2506
16th to endNight
2435%434447%53%
2613
February1st to 15thNight
36%25%436%5%5%8%48%
2270
16th to endNight
38%35%4345%5%7%48%
1894
March1st to 15thNight
45%24425%46%7%52%
2133
16th to endNight
7%6%36%42445%8%46%
2014
April1st to 15thNight
9%5%35%5%3446%7%45%
1798
16th to endNight
14%5%35%5%24446%42%
1788
May1st to 15thNight
10%5%24425%45%7%48%
1496
16th to endNight
10%314425%5%5%9%45%
1497
June1st to 15thNight
7%413225%47%9%52%
1440
16th to endNight
22221335%8%66%
1440
July1st to 15thNight
5%21232446%9%57%
1440
16th to endNight
411233346%8%61%
1512
August1st to 15thNight
22133245%6%10%56%
1539
16th to endNight
332442445%6%58%
1750
September1st to 15thNight
6%5%34422346%56%
1650
16th to endNight
5%22323235%67%
1772
October1st to 15thNight
11%5%24324346%50%
1974
16th to endNight
5%5%2332335%6%57%
2181
November1st to 15thNight
44134235%5%7%57%
2275
16th to endNight
25%2332436%8%56%
2472
December1st to 15thNight
47%35%434449%49%
2520
16th to endNight
37%2443446%8%48%
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
26%8%21%30%11%1
1433
16th to endDay
27%5%19%30%15%2
1620
February1st to 15thDay
33%8%19%26%10%2
1581
16th to endDay
35%6%16%25%11%4
1580
March1st to 15thDay
28%5%15%30%16%3
1827
16th to endDay
34%7%13%28%13%2
2208
April1st to 15thDay
34%6%15%26%13%3
2150
16th to endDay
44%6%13%20%13%1
2172
May1st to 15thDay
40%7%13%24%13%1
2452
16th to endDay
39%9%15%21%11%2
2620
June1st to 15thDay
29%7%15%24%17%5%
2520
16th to endDay
16%5%12%24%27%13%
2520
July1st to 15thDay
25%5%12%21%20%14%
2371
16th to endDay
23%7%10%22%21%15%
2489
August1st to 15thDay
23%8%12%23%18%13%
2317
16th to endDay
22%410%20%25%16%
2100
September1st to 15thDay
27%49%18%24%15%
1980
16th to endDay
18%47%31%29%7%
1857
October1st to 15thDay
31%5%13%27%16%5%
1653
16th to endDay
24%5%15%30%18%6%
1680
November1st to 15thDay
24%6%14%24%22%6%
1583
16th to endDay
24%6%16%28%20%2
1486
December1st to 15thDay
32%7%22%25%11%
1440
16th to endDay
31%5%19%28%12%2
1536
January1st to 15thNight
29%8%16%29%14%2
2506
16th to endNight
29%5%16%29%15%3
2613
February1st to 15thNight
31%8%19%27%10%2
2281
16th to endNight
33%5%16%25%15%3
1894
March1st to 15thNight
29%6%13%27%17%5%
2133
16th to endNight
35%6%15%26%14%2
2014
April1st to 15thNight
36%8%13%23%13%4
1798
16th to endNight
42%6%12%23%14%1
1788
May1st to 15thNight
34%7%14%25%16%1
1497
16th to endNight
34%9%17%22%13%2
1498
June1st to 15thNight
26%7%20%26%15%3
1440
16th to endNight
15%5%14%28%25%10%
1440
July1st to 15thNight
23%5%12%26%19%11%
1360
16th to endNight
19%6%12%24%22%14%
1416
August1st to 15thNight
20%6%15%29%17%10%
1531
16th to endNight
25%49%20%25%15%
1750
September1st to 15thNight
28%48%24%22%12%
1650
16th to endNight
20%36%32%26%10%
1772
October1st to 15thNight
33%5%13%21%20%4
1974
16th to endNight
26%5%13%28%18%7%
2181
November1st to 15thNight
25%5%13%24%23%7%
2275
16th to endNight
24%5%13%32%19%4
2472
December1st to 15thNight
32%6%19%28%11%1
2520
16th to endNight
32%7%18%28%12%1
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
8%5%25%31%15%13%
90
16th to endDay
46%40%32%13%3
96
February1st to 15thDay
8%16%44%23%6%
90
16th to endDay
9%19%33%25%9%1
81
March1st to 15thDay
11%14%29%29%12%
117
16th to endDay
12%15%40%22%6%
288
April1st to 15thDay
15%17%40%17%7%1
269
16th to endDay
21%15%28%22%9%2
282
May1st to 15thDay
14%11%29%25%15%4
468
16th to endDay
15%9%25%29%16%3
517
June1st to 15thDay
8%7%30%29%17%6%
495
16th to endDay
3431%35%23%1
495
July1st to 15thDay
4319%36%30%6%
475
16th to endDay
4124%37%27%4
515
August1st to 15thDay
6%325%33%27%3
357
16th to endDay
7%6%25%31%19%8%
268
September1st to 15thDay
8%6%35%27%20%2
255
16th to endDay
5%6%28%22%25%12%
132
October1st to 15thDay
7%7%16%37%22%7%
90
16th to endDay
7%5%30%32%18%6%
96
November1st to 15thDay
2330%31%18%14%
90
16th to endDay
13%15%38%27%4
90
December1st to 15thDay
6%14%37%26%12%2
90
16th to endDay
7%6%32%36%15%2
96
January1st to 15thNight
416%36%29%12%1
900
16th to endNight
6%13%40%30%8%
885
February1st to 15thNight
6%9%37%37%9%
704
16th to endNight
7%9%41%31%8%
632
March1st to 15thNight
7%8%37%36%9%
720
16th to endNight
10%8%35%37%7%
670
April1st to 15thNight
11%10%35%36%6%
539
16th to endNight
15%9%32%31%10%
540
May1st to 15thNight
13%8%29%35%12%1
540
16th to endNight
12%5%29%34%16%1
563
June1st to 15thNight
9%6%35%35%13%
540
16th to endNight
3233%47%12%
540
July1st to 15thNight
7%124%43%21%1
510
16th to endNight
4121%50%21%
564
August1st to 15thNight
4123%49%20%
527
16th to endNight
4221%47%24%
525
September1st to 15thNight
8%424%41%20%1
495
16th to endNight
6%326%41%20%2
492
October1st to 15thNight
13%6%28%33%15%2
654
16th to endNight
8%5%32%37%14%1
773
November1st to 15thNight
5%9%32%35%15%
875
16th to endNight
5%9%36%39%7%1
900
December1st to 15thNight
7%11%41%31%8%
900
16th to endNight
8%12%35%35%8%
960
Page generated at 2017-08-13 12:16:58. Version ac04

Copyright 2017 A. Danko


Glendo State Park Clear Sky Chart | Charts Home