Warren Dunes State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Warren Dunes State Park clear sky chart from 2005-11-05 to 2017-12-20.

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
35%
16341
15%
48009
10%
16299
40%
16299
20%
34000

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
14%
900
7%
2506
3%
895
18%
895
10%
2068
January16th to endNight
16%
960
6%
2688
3%
960
19%
960
10%
2242
February1st to 15thNight
19%
734
8%
2169
4%
734
23%
734
11%
1724
February16th to endNight
21%
631
12%
1893
5%
631
27%
631
12%
1464
March1st to 15thNight
27%
720
13%
2160
9%
720
30%
720
17%
1561
March16th to endNight
34%
690
17%
2037
11%
690
40%
690
21%
1429
April1st to 15thNight
32%
539
14%
1797
11%
539
39%
539
19%
1246
April16th to endNight
33%
540
20%
1685
11%
540
41%
540
22%
1114
May1st to 15thNight
38%
540
15%
1620
9%
540
44%
540
22%
1114
May16th to endNight
51%
562
17%
1543
11%
561
55%
561
31%
980
June1st to 15thNight
54%
540
17%
1440
12%
540
58%
540
36%
885
June16th to endNight
52%
540
14%
1440
8%
540
56%
540
32%
918
July1st to 15thNight
65%
510
18%
1360
13%
510
67%
510
41%
804
July16th to endNight
70%
564
21%
1417
17%
531
71%
531
42%
810
August1st to 15thNight
71%
539
23%
1581
20%
536
73%
536
38%
895
August16th to endNight
65%
573
21%
1890
21%
573
68%
573
31%
1067
September1st to 15thNight
61%
585
25%
1845
24%
585
64%
585
32%
1077
September16th to endNight
57%
717
26%
1980
21%
717
60%
717
34%
1212
October1st to 15thNight
46%
720
22%
2007
17%
720
50%
720
28%
1310
October16th to endNight
24%
768
15%
2490
9%
768
32%
768
15%
1753
November1st to 15thNight
30%
760
17%
2471
14%
760
35%
760
18%
1704
November16th to endNight
21%
780
12%
2535
9%
780
25%
780
12%
1954
December1st to 15thNight
14%
945
5%
2700
2%
945
17%
945
8%
2273
December16th to endNight
12%
984
6%
2755
1%
984
15%
984
7%
2396

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%46%5%3445%7%36%
48845
Night
16%10%47%5%24446%33%
48177
Cloud CoverDay
14%8%46%5%2445%7%35%
48854
Night
16%10%46%5%34446%33%
48182
TransparencyDay
48%412%21%11%1
48531
Night
52%311%19%11%1
48009
SeeingDay
17%9%26%25%15%6%
6259
Night
21%9%25%28%13%1
16345

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
16%19%7%12%10%4333314%
1432
16th to endDay
13%18%10%11%10%45%33314%
1536
February1st to 15thDay
13%16%8%11%8%45%44419%
1690
16th to endDay
14%11%7%11%8%44446%21%
1580
March1st to 15thDay
16%10%5%8%6%3445%7%27%
1790
16th to endDay
17%8%36%43445%7%34%
2199
April1st to 15thDay
18%8%35%5%23346%36%
2151
16th to endDay
15%7%25%43445%7%39%
2274
May1st to 15thDay
16%7%36%5%25%45%6%36%
2331
16th to endDay
10%426%5%25%46%8%43%
2570
June1st to 15thDay
10%425%5%2445%7%46%
2520
16th to endDay
8%425%435%5%7%9%44%
2520
July1st to 15thDay
6%4145%35%5%6%8%49%
2520
16th to endDay
5%223435%5%7%11%49%
2655
August1st to 15thDay
6%4244346%6%9%47%
2370
16th to endDay
9%4145%245%5%9%46%
2309
September1st to 15thDay
12%42442435%7%47%
2102
16th to endDay
10%6%245%2446%8%43%
1980
October1st to 15thDay
19%7%244245%45%39%
1953
16th to endDay
24%7%25%5%35%45%7%29%
1734
November1st to 15thDay
19%11%34423447%34%
1717
16th to endDay
18%18%6%8%424335%24%
1755
December1st to 15thDay
18%20%10%11%5%2333416%
1589
16th to endDay
21%19%8%10%6%24335%14%
1568
January1st to 15thNight
20%16%7%9%7%2344417%
2506
16th to endNight
14%17%9%12%8%4443417%
2688
February1st to 15thNight
17%13%5%10%7%44445%22%
2167
16th to endNight
17%14%7%10%6%34235%24%
1893
March1st to 15thNight
16%12%47%5%33435%32%
2147
16th to endNight
16%9%46%5%25%447%33%
2037
April1st to 15thNight
18%8%36%5%3445%6%33%
1797
16th to endNight
18%6%35%43445%5%38%
1685
May1st to 15thNight
19%6%35%5%2445%7%35%
1620
16th to endNight
11%434425%46%8%43%
1541
June1st to 15thNight
10%42442445%8%47%
1440
16th to endNight
8%336%5%35%6%7%9%41%
1440
July1st to 15thNight
5%2135%36%5%6%8%51%
1440
16th to endNight
8%21332437%10%50%
1513
August1st to 15thNight
5%3244345%6%8%51%
1590
16th to endNight
10%424434448%49%
1890
September1st to 15thNight
13%5%13424347%48%
1845
16th to endNight
12%5%15%413447%47%
1980
October1st to 15thNight
18%6%24323346%42%
2007
16th to endNight
27%8%26%42233432%
2490
November1st to 15thNight
19%12%45%423345%34%
2471
16th to endNight
19%18%5%8%5%23335%24%
2535
December1st to 15thNight
20%23%9%10%5%2323415%
2700
16th to endNight
21%20%8%11%7%3334311%
2755

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
17%18%6%12%7%4443414%
1432
16th to endDay
14%18%11%10%9%45%33314%
1536
February1st to 15thDay
14%16%7%12%7%35%35%419%
1690
16th to endDay
14%12%8%11%7%44346%21%
1580
March1st to 15thDay
16%11%6%6%6%3445%7%27%
1800
16th to endDay
18%9%36%5%2435%7%33%
2198
April1st to 15thDay
19%10%35%424347%35%
2151
16th to endDay
16%8%25%424447%38%
2274
May1st to 15thDay
19%7%35%5%2445%5%35%
2331
16th to endDay
11%5%35%5%25%46%8%42%
2570
June1st to 15thDay
10%5%345%2445%7%46%
2520
16th to endDay
9%425%435%5%7%8%44%
2520
July1st to 15thDay
7%3245%35%5%5%7%48%
2520
16th to endDay
5%3244345%7%10%48%
2655
August1st to 15thDay
6%4245%25%5%6%8%47%
2370
16th to endDay
11%3245%3446%8%45%
2309
September1st to 15thDay
13%415%43445%7%46%
2102
16th to endDay
11%5%24425%5%6%8%43%
1980
October1st to 15thDay
19%7%25%324446%39%
1953
16th to endDay
24%8%245%3445%7%29%
1734
November1st to 15thDay
20%11%34422446%34%
1717
16th to endDay
19%17%6%8%424335%24%
1755
December1st to 15thDay
18%19%11%11%6%2323417%
1589
16th to endDay
21%20%7%9%6%24335%15%
1568
January1st to 15thNight
21%15%7%10%7%33435%17%
2506
16th to endNight
15%17%10%11%7%3434417%
2688
February1st to 15thNight
16%14%6%9%7%3443423%
2160
16th to endNight
17%14%7%9%6%35%23425%
1893
March1st to 15thNight
17%12%5%7%433445%32%
2160
16th to endNight
17%9%36%425%45%7%33%
2037
April1st to 15thNight
18%8%36%5%25%447%33%
1797
16th to endNight
18%6%35%43345%5%38%
1685
May1st to 15thNight
19%6%35%5%3445%7%35%
1619
16th to endNight
13%425%42446%8%43%
1541
June1st to 15thNight
10%4244235%5%8%47%
1440
16th to endNight
8%335%5%35%6%7%9%41%
1440
July1st to 15thNight
6%2136%25%47%8%51%
1440
16th to endNight
7%21332447%10%51%
1513
August1st to 15thNight
5%41443446%8%52%
1590
16th to endNight
10%423424448%48%
1890
September1st to 15thNight
14%423322447%50%
1845
16th to endNight
12%5%24433347%47%
1980
October1st to 15thNight
19%5%2342335%6%42%
2007
16th to endNight
27%7%26%5%2233433%
2490
November1st to 15thNight
19%13%35%423345%35%
2471
16th to endNight
20%18%6%8%423335%24%
2535
December1st to 15thNight
20%21%9%9%6%2333416%
2700
16th to endNight
21%21%7%11%6%2433412%
2755

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
74%112%8%2
1433
16th to endDay
76%28%8%3
1536
February1st to 15thDay
68%39%12%41
1692
16th to endDay
65%311%13%4
1580
March1st to 15thDay
56%313%17%7%
1800
16th to endDay
51%412%25%5%1
2199
April1st to 15thDay
50%39%21%14%
2151
16th to endDay
45%313%21%12%4
2274
May1st to 15thDay
49%313%23%9%
2331
16th to endDay
39%412%27%13%2
2574
June1st to 15thDay
37%49%27%19%1
2520
16th to endDay
35%5%14%23%18%2
2520
July1st to 15thDay
35%411%25%21%2
2371
16th to endDay
29%7%15%27%17%2
2488
August1st to 15thDay
32%5%13%28%17%2
2355
16th to endDay
36%5%12%25%16%3
2309
September1st to 15thDay
37%412%25%17%3
2102
16th to endDay
36%5%10%28%16%1
1980
October1st to 15thDay
45%39%25%13%1
1953
16th to endDay
54%313%19%7%
1734
November1st to 15thDay
50%311%20%12%1
1717
16th to endDay
64%210%18%3
1755
December1st to 15thDay
72%29%12%3
1589
16th to endDay
73%212%8%2
1568
January1st to 15thNight
69%210%11%4
2506
16th to endNight
70%213%9%2
2688
February1st to 15thNight
64%310%13%5%
2169
16th to endNight
63%210%18%4
1893
March1st to 15thNight
54%313%16%9%1
2160
16th to endNight
50%312%22%8%1
2037
April1st to 15thNight
51%39%19%14%
1797
16th to endNight
46%38%20%15%4
1685
May1st to 15thNight
48%411%23%10%1
1620
16th to endNight
38%415%24%15%2
1543
June1st to 15thNight
34%411%28%18%2
1440
16th to endNight
37%5%17%22%15%1
1440
July1st to 15thNight
29%5%13%26%21%2
1360
16th to endNight
27%5%17%26%19%4
1417
August1st to 15thNight
30%411%29%22%1
1581
16th to endNight
34%410%26%19%4
1890
September1st to 15thNight
35%310%25%20%4
1845
16th to endNight
36%28%28%21%2
1980
October1st to 15thNight
42%39%25%17%1
2007
16th to endNight
55%211%22%8%1
2490
November1st to 15thNight
52%29%19%12%2
2471
16th to endNight
63%311%17%4
2535
December1st to 15thNight
73%28%11%3
2700
16th to endNight
76%29%8%1
2755

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
24%18%32%15%8%
90
16th to endDay
28%14%31%18%6%1
96
February1st to 15thDay
25%34%28%8%2
90
16th to endDay
18%18%38%16%7%1
81
March1st to 15thDay
31%21%27%15%4
90
16th to endDay
31%10%25%20%10%1
285
April1st to 15thDay
27%11%31%21%6%1
270
16th to endDay
20%11%32%18%10%6%
270
May1st to 15thDay
26%10%27%20%11%5%
288
16th to endDay
14%11%28%27%13%4
470
June1st to 15thDay
11%7%30%32%15%3
495
16th to endDay
12%7%33%27%13%5%
495
July1st to 15thDay
9%430%27%20%8%
475
16th to endDay
6%222%36%20%9%
515
August1st to 15thDay
8%115%28%29%16%
343
16th to endDay
14%314%29%24%12%
332
September1st to 15thDay
14%315%26%29%10%
315
16th to endDay
12%7%12%29%24%13%
314
October1st to 15thDay
22%425%25%19%2
288
16th to endDay
29%12%35%18%4
144
November1st to 15thDay
20%8%29%25%12%2
135
16th to endDay
31%21%30%13%2
135
December1st to 15thDay
26%29%25%11%5%
135
16th to endDay
23%32%39%3
108
January1st to 15thNight
29%13%34%17%4
900
16th to endNight
23%14%34%25%2
960
February1st to 15thNight
23%15%33%22%4
737
16th to endNight
23%15%30%23%6%
631
March1st to 15thNight
24%12%30%23%8%
720
16th to endNight
20%9%29%31%7%
690
April1st to 15thNight
22%12%28%28%7%
539
16th to endNight
21%8%31%25%10%1
540
May1st to 15thNight
22%426%32%12%1
540
16th to endNight
15%320%39%20%
563
June1st to 15thNight
14%220%43%18%1
540
16th to endNight
10%126%38%21%1
540
July1st to 15thNight
7%218%42%26%2
510
16th to endNight
8%212%40%31%4
564
August1st to 15thNight
7%110%45%29%5%
539
16th to endNight
12%110%37%32%5%
573
September1st to 15thNight
15%311%36%26%6%
585
16th to endNight
14%417%29%29%4
717
October1st to 15thNight
22%5%20%31%17%1
720
16th to endNight
31%13%25%22%6%
768
November1st to 15thNight
25%9%27%25%10%
760
16th to endNight
31%14%26%21%6%
780
December1st to 15thNight
31%15%30%18%4
945
16th to endNight
30%12%35%18%2
984
Page generated at 2017-12-21 07:04:52. Version ac04

Copyright 2017 A. Danko


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