Hennepin Canal Parkway State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hennepin Canal Parkway State Park clear sky chart from 2005-11-05 to 2017-09-21.

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%
15977
19%
46897
11%
15934
45%
15934
25%
30540

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
20%
900
15%
2506
5%
895
30%
895
20%
1770
January16th to endNight
21%
960
14%
2583
4%
960
28%
960
18%
1893
February1st to 15thNight
23%
847
14%
2259
3%
847
31%
847
21%
1603
February16th to endNight
25%
631
18%
1893
6%
631
35%
631
21%
1270
March1st to 15thNight
28%
699
16%
2139
9%
699
34%
699
20%
1456
March16th to endNight
27%
576
14%
2010
9%
576
35%
576
17%
1378
April1st to 15thNight
28%
539
17%
1797
11%
539
39%
539
21%
1178
April16th to endNight
35%
540
19%
1797
13%
540
44%
540
21%
1198
May1st to 15thNight
34%
540
17%
1536
9%
540
42%
540
25%
1046
May16th to endNight
48%
563
19%
1497
11%
561
54%
561
32%
978
June1st to 15thNight
56%
540
17%
1440
11%
540
59%
540
36%
888
June16th to endNight
50%
540
18%
1440
10%
540
55%
540
34%
919
July1st to 15thNight
66%
510
18%
1360
12%
510
68%
510
42%
796
July16th to endNight
74%
564
24%
1417
18%
531
76%
531
44%
811
August1st to 15thNight
74%
539
23%
1611
23%
536
75%
536
42%
863
August16th to endNight
67%
573
23%
1910
23%
573
72%
573
35%
1058
September1st to 15thNight
62%
540
29%
1800
30%
540
67%
540
38%
956
September16th to endNight
56%
642
27%
1842
19%
642
62%
642
36%
1069
October1st to 15thNight
47%
660
28%
1960
21%
660
54%
660
35%
1135
October16th to endNight
30%
704
19%
2186
10%
704
40%
704
24%
1384
November1st to 15thNight
32%
700
25%
2276
15%
700
45%
700
27%
1337
November16th to endNight
27%
810
19%
2430
10%
810
36%
810
23%
1602
December1st to 15thNight
20%
900
13%
2520
5%
900
28%
900
19%
1840
December16th to endNight
17%
960
12%
2688
3%
960
25%
960
13%
2112

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%7%36%5%3445%7%37%
47970
Night
13%7%35%424446%41%
47066
Cloud CoverDay
13%7%35%5%3445%7%37%
47978
Night
13%7%35%424446%41%
47071
TransparencyDay
44%5%12%22%12%1
47656
Night
42%412%23%14%2
46898
SeeingDay
15%7%25%27%18%6%
5995
Night
17%8%29%30%12%1
15980

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%11%5%9%7%45%5%5%6%25%
1432
16th to endDay
14%14%6%8%7%4444426%
1638
February1st to 15thDay
15%12%5%8%425%445%30%
1603
16th to endDay
13%9%48%7%33447%32%
1580
March1st to 15thDay
15%10%47%5%2435%6%34%
1820
16th to endDay
17%9%47%6%345%5%7%29%
2214
April1st to 15thDay
16%10%5%7%5%2335%5%35%
2151
16th to endDay
20%8%35%5%1435%6%33%
2160
May1st to 15thDay
18%8%26%5%25%5%5%7%30%
2412
16th to endDay
14%6%35%6%35%5%5%7%36%
2617
June1st to 15thDay
11%5%245%35%45%8%42%
2520
16th to endDay
9%4245%36%6%6%9%40%
2520
July1st to 15thDay
6%4145%345%6%10%45%
2520
16th to endDay
7%425%5%35%6%6%10%42%
2655
August1st to 15thDay
6%4245%35%5%7%9%42%
2337
16th to endDay
10%42343445%7%47%
2292
September1st to 15thDay
12%41433345%7%48%
2160
16th to endDay
8%425%4345%47%47%
1899
October1st to 15thDay
14%6%24422346%48%
1669
16th to endDay
17%7%345%33445%39%
1686
November1st to 15thDay
13%8%243335%5%6%42%
1582
16th to endDay
17%10%46%424235%38%
1527
December1st to 15thDay
18%12%5%7%6%35%435%27%
1440
16th to endDay
19%15%5%8%6%22445%24%
1536
January1st to 15thNight
14%10%37%5%24446%35%
2506
16th to endNight
11%10%6%8%6%34346%31%
2583
February1st to 15thNight
14%10%47%5%3445%5%35%
2257
16th to endNight
14%9%46%6%33335%38%
1893
March1st to 15thNight
16%9%35%5%34445%38%
2126
16th to endNight
16%9%36%5%3445%6%32%
2010
April1st to 15thNight
16%9%36%423446%39%
1797
16th to endNight
18%8%35%5%2445%6%36%
1797
May1st to 15thNight
16%6%245%35%5%47%37%
1536
16th to endNight
9%5%245%345%6%9%42%
1496
June1st to 15thNight
10%5%245%24346%50%
1440
16th to endNight
7%3245%45%5%5%8%45%
1440
July1st to 15thNight
6%31422445%9%53%
1440
16th to endNight
5%213335%5%7%11%49%
1513
August1st to 15thNight
332342446%8%55%
1620
16th to endNight
8%42432445%7%52%
1910
September1st to 15thNight
10%412413346%57%
1800
16th to endNight
7%3144336%6%8%48%
1842
October1st to 15thNight
11%5%24413346%53%
1960
16th to endNight
18%6%245%24445%42%
2186
November1st to 15thNight
11%7%24322446%49%
2276
16th to endNight
17%7%25%5%2445%6%39%
2430
December1st to 15thNight
18%11%5%7%424345%32%
2520
16th to endNight
21%13%5%8%6%3433424%
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
13%12%5%8%7%35%5%5%7%24%
1432
16th to endDay
14%15%5%8%6%3444426%
1638
February1st to 15thDay
15%11%5%9%425%445%30%
1603
16th to endDay
14%9%5%7%7%245%47%32%
1580
March1st to 15thDay
16%10%47%5%24346%34%
1830
16th to endDay
17%9%46%6%345%47%30%
2212
April1st to 15thDay
16%10%5%6%5%2435%5%35%
2151
16th to endDay
20%8%25%5%2445%6%33%
2160
May1st to 15thDay
18%8%37%5%25%5%5%8%29%
2412
16th to endDay
14%6%35%5%45%45%7%36%
2617
June1st to 15thDay
11%5%245%345%6%7%42%
2520
16th to endDay
9%5%246%36%5%7%9%40%
2520
July1st to 15thDay
6%4245%35%5%6%10%45%
2520
16th to endDay
7%425%5%35%5%7%10%43%
2655
August1st to 15thDay
6%4245%35%5%8%9%42%
2337
16th to endDay
10%5%2342445%7%47%
2292
September1st to 15thDay
12%41441345%7%48%
2160
16th to endDay
9%425%4345%47%47%
1899
October1st to 15thDay
14%6%2442235%5%48%
1669
16th to endDay
17%7%35%423445%39%
1686
November1st to 15thDay
13%8%25%33445%6%41%
1582
16th to endDay
17%10%46%323336%37%
1527
December1st to 15thDay
18%12%46%6%25%445%28%
1440
16th to endDay
19%14%5%7%7%22445%25%
1536
January1st to 15thNight
14%10%48%5%24446%35%
2506
16th to endNight
11%11%6%9%6%44446%31%
2583
February1st to 15thNight
14%10%47%42445%5%35%
2250
16th to endNight
14%9%47%5%24345%38%
1893
March1st to 15thNight
17%9%35%434335%38%
2139
16th to endNight
17%7%46%5%3445%7%32%
2010
April1st to 15thNight
16%9%35%423346%39%
1797
16th to endNight
18%7%36%5%24346%36%
1797
May1st to 15thNight
16%6%246%25%5%5%7%37%
1535
16th to endNight
9%5%245%345%6%9%42%
1496
June1st to 15thNight
10%425%324446%50%
1440
16th to endNight
8%3245%36%46%8%45%
1440
July1st to 15thNight
6%32323336%9%53%
1440
16th to endNight
4213425%5%7%10%49%
1513
August1st to 15thNight
432342446%8%55%
1620
16th to endNight
8%42442445%7%52%
1910
September1st to 15thNight
10%412323345%57%
1800
16th to endNight
7%3244245%6%8%48%
1842
October1st to 15thNight
10%5%24323346%52%
1960
16th to endNight
17%7%25%423445%42%
2186
November1st to 15thNight
12%7%24213346%49%
2276
16th to endNight
17%7%25%424446%38%
2430
December1st to 15thNight
18%11%5%6%424345%32%
2520
16th to endNight
21%14%5%8%5%3433425%
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
56%5%12%15%9%
1433
16th to endDay
60%411%16%7%
1638
February1st to 15thDay
55%414%18%5%1
1605
16th to endDay
51%414%20%8%
1580
March1st to 15thDay
50%415%21%7%
1830
16th to endDay
52%5%14%21%4
2214
April1st to 15thDay
50%411%23%9%
2151
16th to endDay
51%5%10%19%11%2
2160
May1st to 15thDay
51%5%12%21%8%
2412
16th to endDay
45%7%12%19%14%1
2621
June1st to 15thDay
38%6%12%26%15%1
2520
16th to endDay
38%6%11%23%17%2
2520
July1st to 15thDay
33%6%14%26%15%2
2371
16th to endDay
34%7%17%24%13%2
2488
August1st to 15thDay
33%8%14%25%16%1
2322
16th to endDay
34%5%12%27%16%3
2292
September1st to 15thDay
33%5%9%26%21%4
2160
16th to endDay
35%5%10%28%18%1
1899
October1st to 15thDay
37%49%29%17%1
1669
16th to endDay
45%412%24%10%2
1686
November1st to 15thDay
41%312%25%14%2
1582
16th to endDay
48%415%24%6%
1527
December1st to 15thDay
58%413%16%6%
1440
16th to endDay
61%412%12%8%
1536
January1st to 15thNight
50%312%19%13%
2506
16th to endNight
54%315%16%9%
2583
February1st to 15thNight
49%413%21%10%1
2259
16th to endNight
48%213%23%10%1
1893
March1st to 15thNight
48%313%21%9%2
2139
16th to endNight
51%413%20%8%1
2010
April1st to 15thNight
46%39%23%13%2
1797
16th to endNight
47%49%22%11%4
1797
May1st to 15thNight
44%5%12%23%13%
1536
16th to endNight
35%8%12%23%17%2
1498
June1st to 15thNight
34%412%24%20%2
1440
16th to endNight
34%6%12%21%20%3
1440
July1st to 15thNight
28%412%32%17%3
1360
16th to endNight
25%6%15%30%18%4
1417
August1st to 15thNight
25%5%13%33%17%3
1611
16th to endNight
30%5%11%27%20%4
1910
September1st to 15thNight
28%47%28%27%4
1800
16th to endNight
30%5%10%30%19%3
1842
October1st to 15thNight
32%39%27%23%3
1960
16th to endNight
43%310%25%15%1
2186
November1st to 15thNight
36%410%25%18%4
2276
16th to endNight
45%212%25%12%
2430
December1st to 15thNight
54%212%21%8%
2520
16th to endNight
63%310%15%7%
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
32%8%38%16%3
90
16th to endDay
18%16%34%18%9%2
96
February1st to 15thDay
18%14%44%14%7%
90
16th to endDay
18%16%34%18%11%1
81
March1st to 15thDay
26%21%35%12%31
90
16th to endDay
25%12%30%20%9%2
198
April1st to 15thDay
22%12%31%22%10%1
270
16th to endDay
23%7%27%24%12%3
270
May1st to 15thDay
21%12%28%25%9%2
369
16th to endDay
18%9%26%26%14%5%
517
June1st to 15thDay
11%427%30%21%4
495
16th to endDay
12%5%31%28%16%5%
495
July1st to 15thDay
9%321%31%23%10%
475
16th to endDay
7%121%28%31%9%
515
August1st to 15thDay
8%116%34%26%11%
451
16th to endDay
9%213%33%27%12%
332
September1st to 15thDay
10%314%31%30%9%
315
16th to endDay
8%422%29%30%5%
275
October1st to 15thDay
12%11%21%30%19%5%
109
16th to endDay
19%14%36%21%7%
96
November1st to 15thDay
412%28%23%23%7%
90
16th to endDay
38%13%25%15%6%
90
December1st to 15thDay
21%14%32%26%41
90
16th to endDay
28%18%43%7%2
96
January1st to 15thNight
18%13%40%21%5%
900
16th to endNight
16%14%37%26%4
960
February1st to 15thNight
20%10%37%25%4
850
16th to endNight
20%9%38%25%4
631
March1st to 15thNight
21%10%32%27%6%
699
16th to endNight
21%9%36%24%7%1
576
April1st to 15thNight
22%11%33%27%5%
539
16th to endNight
20%8%31%30%8%
540
May1st to 15thNight
21%6%30%30%9%1
540
16th to endNight
10%429%38%15%
563
June1st to 15thNight
11%323%47%13%
540
16th to endNight
10%329%40%15%1
540
July1st to 15thNight
8%117%41%27%3
510
16th to endNight
5%112%46%30%3
564
August1st to 15thNight
5%11%43%32%5%
539
16th to endNight
10%113%38%33%2
573
September1st to 15thNight
13%313%36%28%5%
540
16th to endNight
10%421%35%24%3
642
October1st to 15thNight
13%5%28%31%19%1
660
16th to endNight
23%8%33%24%9%
704
November1st to 15thNight
17%11%35%25%9%1
700
16th to endNight
21%10%34%25%6%
810
December1st to 15thNight
25%11%34%21%6%
900
16th to endNight
30%10%32%21%4
960
Page generated at 2017-09-22 06:35:31. Version ac04

Copyright 2017 A. Danko


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