Belvidere East KOA
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Belvidere East KOA clear sky chart from 2005-11-05 to 2017-09-23.

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
42%
16125
21%
46895
12%
16080
50%
16080
33%
28123

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
36%
900
19%
2506
11%
895
42%
895
28%
1592
January16th to endNight
35%
960
19%
2688
9%
960
42%
960
28%
1709
February1st to 15thNight
31%
791
15%
2262
6%
789
37%
789
23%
1527
February16th to endNight
37%
632
20%
1894
10%
632
45%
632
28%
1169
March1st to 15thNight
38%
714
20%
2154
10%
714
46%
714
29%
1305
March16th to endNight
34%
576
18%
2045
11%
576
44%
576
23%
1248
April1st to 15thNight
31%
539
17%
1798
9%
539
45%
539
27%
1080
April16th to endNight
35%
540
16%
1647
11%
540
43%
540
25%
1088
May1st to 15thNight
40%
540
19%
1620
12%
540
48%
540
31%
977
May16th to endNight
39%
563
16%
1499
8%
561
42%
561
29%
990
June1st to 15thNight
42%
540
14%
1440
6%
540
44%
540
34%
919
June16th to endNight
51%
540
19%
1440
7%
540
56%
540
50%
792
July1st to 15thNight
60%
510
18%
1360
8%
510
63%
510
51%
732
July16th to endNight
63%
564
25%
1416
15%
531
67%
531
55%
737
August1st to 15thNight
58%
539
23%
1552
16%
536
63%
536
43%
856
August16th to endNight
59%
573
29%
1833
26%
573
70%
573
49%
882
September1st to 15thNight
55%
540
26%
1850
19%
540
68%
540
41%
927
September16th to endNight
48%
516
31%
1903
24%
516
61%
516
40%
884
October1st to 15thNight
43%
533
30%
1853
22%
533
53%
533
31%
1044
October16th to endNight
46%
880
23%
2288
11%
880
52%
880
34%
1441
November1st to 15thNight
41%
875
28%
2275
12%
875
49%
875
37%
1387
November16th to endNight
43%
900
28%
2364
15%
900
51%
900
36%
1445
December1st to 15thNight
33%
900
18%
2520
8%
900
42%
900
25%
1669
December16th to endNight
36%
960
20%
2688
8%
960
46%
960
28%
1723

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
9%5%2442345%7%49%
48020
Night
8%5%2442445%7%48%
47062
Cloud CoverDay
9%5%2442345%7%50%
48029
Night
8%5%2442445%7%48%
47066
Cloud CoverDay
9%5%2442345%7%49%
48030
Night
8%5%2442445%7%48%
47067
Cloud CoverDay
9%5%2442345%7%49%
48028
Night
8%6%2442445%7%48%
47067
TransparencyDay
33%414%27%15%3
47704
Night
34%414%26%16%3
46895
SeeingDay
11%7%29%31%16%3
6091
Night
10%7%33%36%11%
16128

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
6%6%38%6%35%35%7%42%
1432
16th to endDay
5%10%46%5%2335%6%45%
1536
February1st to 15thDay
11%9%5%6%6%24446%39%
1608
16th to endDay
6%8%38%6%22347%46%
1580
March1st to 15thDay
8%6%2442435%7%48%
1796
16th to endDay
13%8%35%43446%7%39%
2178
April1st to 15thDay
14%8%14423347%44%
2150
16th to endDay
17%8%25%43445%6%37%
2312
May1st to 15thDay
15%5%2342446%6%45%
2331
16th to endDay
16%5%1442445%8%42%
2614
June1st to 15thDay
12%31442446%7%48%
2520
16th to endDay
421231446%8%60%
2520
July1st to 15thDay
5%31331345%8%58%
2520
16th to endDay
421232345%7%62%
2656
August1st to 15thDay
5%3135%245%6%9%50%
2400
16th to endDay
7%313312336%61%
2366
September1st to 15thDay
8%31322345%6%58%
2109
16th to endDay
8%212222335%64%
1893
October1st to 15thDay
13%6%24313236%52%
1763
16th to endDay
10%7%24423336%51%
1584
November1st to 15thDay
6%5%24424446%54%
1583
16th to endDay
7%8%25%5%24447%45%
1593
December1st to 15thDay
7%7%48%6%2435%7%42%
1440
16th to endDay
9%7%37%5%2445%7%42%
1536
January1st to 15thNight
5%6%47%5%345%6%7%42%
2506
16th to endNight
5%9%36%42445%6%44%
2688
February1st to 15thNight
9%10%47%5%35%447%38%
2259
16th to endNight
7%7%35%43445%6%46%
1894
March1st to 15thNight
7%7%36%434447%45%
2141
16th to endNight
12%6%35%42435%8%41%
2045
April1st to 15thNight
14%5%24424347%45%
1798
16th to endNight
18%6%245%2445%6%38%
1647
May1st to 15thNight
12%5%14424447%47%
1620
16th to endNight
12%5%24435%46%8%42%
1498
June1st to 15thNight
14%3244235%5%7%47%
1440
16th to endNight
421233447%7%57%
1440
July1st to 15thNight
5%312213448%60%
1440
16th to endNight
321332335%9%62%
1512
August1st to 15thNight
421442446%9%54%
1560
16th to endNight
421332335%7%63%
1833
September1st to 15thNight
7%313323346%60%
1850
16th to endNight
8%212212346%62%
1903
October1st to 15thNight
15%413323445%51%
1853
16th to endNight
10%424435%447%49%
2288
November1st to 15thNight
7%6%25%3245%5%6%51%
2275
16th to endNight
5%6%35%424448%50%
2364
December1st to 15thNight
7%10%36%6%3445%6%41%
2520
16th to endNight
8%8%36%32445%7%43%
2688

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
6%7%38%6%45%447%41%
1433
16th to endDay
5%10%36%6%2235%6%45%
1536
February1st to 15thDay
10%9%46%6%24446%39%
1608
16th to endDay
5%9%37%6%23337%47%
1580
March1st to 15thDay
8%5%3443345%8%49%
1806
16th to endDay
13%8%25%42445%8%39%
2176
April1st to 15thDay
14%7%23424347%44%
2150
16th to endDay
17%7%24425%45%6%37%
2312
May1st to 15thDay
16%42442445%6%45%
2331
16th to endDay
15%5%14424348%42%
2614
June1st to 15thDay
12%3145%2445%7%48%
2520
16th to endDay
32332445%8%60%
2520
July1st to 15thDay
5%2132245%5%8%58%
2520
16th to endDay
421332345%7%62%
2656
August1st to 15thDay
5%3144245%7%9%50%
2400
16th to endDay
7%313312346%61%
2366
September1st to 15thDay
8%323323446%58%
2109
16th to endDay
8%212212335%65%
1893
October1st to 15thDay
13%5%24312336%51%
1763
16th to endDay
10%6%24423336%51%
1584
November1st to 15thDay
7%424324347%53%
1583
16th to endDay
7%8%35%42445%7%45%
1593
December1st to 15thDay
7%8%48%5%2435%7%43%
1440
16th to endDay
8%7%47%5%3345%6%42%
1536
January1st to 15thNight
5%6%47%5%35%5%5%7%42%
2506
16th to endNight
5%8%46%5%25%45%7%44%
2688
February1st to 15thNight
9%10%37%435%446%38%
2252
16th to endNight
7%7%36%425%45%6%46%
1894
March1st to 15thNight
7%6%36%5%2445%7%46%
2154
16th to endNight
12%7%45%42345%9%40%
2043
April1st to 15thNight
14%5%24424447%45%
1798
16th to endNight
18%6%2443445%7%38%
1647
May1st to 15thNight
12%5%1342445%8%46%
1619
16th to endNight
13%5%2443445%9%41%
1499
June1st to 15thNight
14%41442346%6%47%
1440
16th to endNight
421233447%8%56%
1440
July1st to 15thNight
5%21322445%8%60%
1440
16th to endNight
32322335%8%63%
1512
August1st to 15thNight
42145%245%5%9%54%
1560
16th to endNight
4212323347%63%
1833
September1st to 15thNight
7%213223346%61%
1850
16th to endNight
8%312213337%62%
1903
October1st to 15thNight
15%423323345%51%
1853
16th to endNight
10%424434447%48%
2288
November1st to 15thNight
7%5%244145%5%6%51%
2275
16th to endNight
5%6%34423448%50%
2364
December1st to 15thNight
7%9%36%5%35%446%42%
2520
16th to endNight
8%8%35%42445%7%44%
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
6%6%47%6%45%35%6%42%
1432
16th to endDay
5%9%46%6%2335%7%45%
1536
February1st to 15thDay
10%9%47%5%33446%39%
1608
16th to endDay
6%7%48%5%33337%45%
1580
March1st to 15thDay
7%6%25%42345%7%49%
1806
16th to endDay
13%8%25%42346%7%39%
2178
April1st to 15thDay
14%7%24423347%44%
2150
16th to endDay
17%7%25%43445%6%37%
2312
May1st to 15thDay
15%5%2342346%6%45%
2331
16th to endDay
16%5%24324449%41%
2614
June1st to 15thDay
12%31442445%8%48%
2520
16th to endDay
421222446%8%60%
2520
July1st to 15thDay
5%2123235%5%9%57%
2520
16th to endDay
421332345%7%62%
2656
August1st to 15thDay
5%4134245%7%9%50%
2400
16th to endDay
7%413312336%61%
2366
September1st to 15thDay
8%31321335%6%58%
2109
16th to endDay
8%212222335%64%
1893
October1st to 15thDay
13%6%34313236%51%
1763
16th to endDay
10%7%24323335%51%
1584
November1st to 15thDay
7%5%24324437%54%
1583
16th to endDay
7%8%35%5%23447%45%
1593
December1st to 15thDay
7%6%48%5%2335%6%43%
1440
16th to endDay
8%7%37%5%2435%7%42%
1536
January1st to 15thNight
5%6%37%6%345%6%7%42%
2506
16th to endNight
5%8%46%425%45%6%44%
2688
February1st to 15thNight
9%9%47%5%35%446%38%
2252
16th to endNight
8%7%36%4345%46%46%
1894
March1st to 15thNight
8%7%35%43445%7%46%
2154
16th to endNight
12%6%35%43435%9%40%
2045
April1st to 15thNight
13%5%2442435%7%45%
1798
16th to endNight
18%6%245%2445%7%38%
1647
May1st to 15thNight
12%5%13424448%47%
1619
16th to endNight
13%424425%46%7%42%
1498
June1st to 15thNight
14%32442345%6%47%
1440
16th to endNight
42123345%7%8%57%
1440
July1st to 15thNight
5%31221445%9%59%
1440
16th to endNight
311332345%8%62%
1512
August1st to 15thNight
42145%2446%8%55%
1560
16th to endNight
431332335%7%63%
1833
September1st to 15thNight
8%213323346%60%
1850
16th to endNight
8%311212346%62%
1903
October1st to 15thNight
15%413323445%51%
1853
16th to endNight
10%5%24434446%49%
2288
November1st to 15thNight
7%6%243245%5%6%51%
2275
16th to endNight
6%6%25%42435%8%50%
2364
December1st to 15thNight
7%9%36%6%3445%5%41%
2520
16th to endNight
8%8%36%42445%6%44%
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
6%6%47%6%45%45%7%41%
1432
16th to endDay
5%10%36%6%23347%45%
1536
February1st to 15thDay
10%9%48%6%33446%39%
1608
16th to endDay
6%7%48%6%23347%44%
1580
March1st to 15thDay
8%6%35%424447%49%
1806
16th to endDay
13%8%35%5%2445%8%38%
2176
April1st to 15thDay
14%7%24323447%44%
2150
16th to endDay
17%6%35%42445%6%37%
2312
May1st to 15thDay
15%5%2333445%6%45%
2331
16th to endDay
16%5%2432445%9%41%
2614
June1st to 15thDay
11%41442445%7%47%
2520
16th to endDay
421222446%8%59%
2520
July1st to 15thDay
5%3123135%6%8%57%
2520
16th to endDay
321322335%7%61%
2656
August1st to 15thDay
5%4144245%7%9%50%
2400
16th to endDay
7%313312337%60%
2366
September1st to 15thDay
8%31332335%6%58%
2109
16th to endDay
8%212223235%64%
1893
October1st to 15thDay
13%5%24313236%51%
1763
16th to endDay
10%8%24313335%51%
1584
November1st to 15thDay
7%5%24324437%53%
1583
16th to endDay
7%9%35%5%2445%7%45%
1593
December1st to 15thDay
7%7%48%5%2435%6%42%
1440
16th to endDay
8%8%47%5%3345%7%42%
1536
January1st to 15thNight
5%6%47%6%345%6%7%42%
2506
16th to endNight
5%8%46%5%35%45%7%43%
2688
February1st to 15thNight
8%10%47%5%44446%38%
2252
16th to endNight
8%7%36%43445%5%46%
1894
March1st to 15thNight
8%6%36%5%2445%7%45%
2154
16th to endNight
12%7%35%433449%40%
2045
April1st to 15thNight
13%6%2432345%7%45%
1798
16th to endNight
18%6%244245%46%39%
1647
May1st to 15thNight
12%5%1342445%6%47%
1619
16th to endNight
13%5%34426%45%8%42%
1498
June1st to 15thNight
14%3245%2345%7%46%
1440
16th to endNight
421242447%8%57%
1440
July1st to 15thNight
5%21231445%9%59%
1440
16th to endNight
221221346%8%63%
1512
August1st to 15thNight
42135%3446%9%54%
1560
16th to endNight
4312313347%63%
1833
September1st to 15thNight
8%213323346%60%
1850
16th to endNight
8%312212347%62%
1903
October1st to 15thNight
15%413223346%50%
1853
16th to endNight
9%5%244345%46%48%
2288
November1st to 15thNight
7%6%2432445%6%51%
2275
16th to endNight
5%6%25%42435%8%50%
2364
December1st to 15thNight
7%9%46%6%3445%6%41%
2520
16th to endNight
8%8%45%4245%5%6%43%
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
40%417%26%10%1
1433
16th to endDay
38%5%21%22%10%1
1536
February1st to 15thDay
45%416%22%9%1
1609
16th to endDay
40%416%25%10%3
1580
March1st to 15thDay
33%5%16%29%13%1
1806
16th to endDay
43%5%15%25%9%
2178
April1st to 15thDay
39%414%30%10%1
2150
16th to endDay
46%414%24%9%
2312
May1st to 15thDay
38%314%29%12%
2331
16th to endDay
39%5%19%24%10%
2618
June1st to 15thDay
34%5%18%26%13%1
2520
16th to endDay
20%415%32%21%5%
2520
July1st to 15thDay
23%5%13%27%23%7%
2371
16th to endDay
20%49%30%24%9%
2489
August1st to 15thDay
27%5%15%28%17%5%
2384
16th to endDay
24%312%29%22%7%
2366
September1st to 15thDay
25%410%28%24%6%
2109
16th to endDay
22%39%34%25%3
1893
October1st to 15thDay
35%311%23%20%5%
1763
16th to endDay
34%314%31%13%2
1584
November1st to 15thDay
30%315%24%19%5%
1583
16th to endDay
38%315%26%14%1
1593
December1st to 15thDay
41%418%22%11%1
1440
16th to endDay
40%417%24%11%
1536
January1st to 15thNight
38%417%23%12%2
2506
16th to endNight
39%418%24%12%1
2688
February1st to 15thNight
46%415%22%10%1
2262
16th to endNight
38%415%25%11%3
1894
March1st to 15thNight
37%315%26%14%2
2154
16th to endNight
41%416%24%11%1
2045
April1st to 15thNight
38%415%25%14%1
1798
16th to endNight
44%415%21%11%1
1647
May1st to 15thNight
36%412%29%16%1
1620
16th to endNight
38%6%17%23%11%1
1499
June1st to 15thNight
36%415%26%14%1
1440
16th to endNight
23%315%33%19%4
1440
July1st to 15thNight
20%415%27%24%7%
1360
16th to endNight
19%313%30%22%11%
1416
August1st to 15thNight
25%5%14%28%20%5%
1552
16th to endNight
20%311%29%26%8%
1833
September1st to 15thNight
25%311%25%24%8%
1850
16th to endNight
23%38%33%27%3
1903
October1st to 15thNight
34%310%24%22%5%
1853
16th to endNight
35%413%24%17%4
2288
November1st to 15thNight
32%411%23%22%6%
2275
16th to endNight
31%5%15%27%15%3
2364
December1st to 15thNight
43%314%26%9%2
2520
16th to endNight
39%5%18%23%11%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%436%27%13%8%
90
16th to endDay
11%7%25%33%16%6%
96
February1st to 15thDay
13%6%40%33%6%
90
16th to endDay
11%24%28%18%12%4
81
March1st to 15thDay
10%5%43%24%12%4
90
16th to endDay
20%8%29%26%12%3
162
April1st to 15thDay
15%15%34%25%8%
269
16th to endDay
21%10%31%25%10%1
422
May1st to 15thDay
15%10%32%23%15%2
468
16th to endDay
18%6%30%29%13%2
517
June1st to 15thDay
11%6%31%29%16%5%
495
16th to endDay
7%6%34%35%15%1
495
July1st to 15thDay
5%324%39%22%3
475
16th to endDay
3426%43%20%2
515
August1st to 15thDay
4325%42%21%2
493
16th to endDay
10%322%33%25%5%
406
September1st to 15thDay
9%9%20%27%25%8%
264
16th to endDay
9%6%33%33%17%
111
October1st to 15thDay
14%8%30%25%15%5%
90
16th to endDay
15%10%18%29%22%3
96
November1st to 15thDay
6%424%32%22%10%
90
16th to endDay
25%12%22%25%14%
90
December1st to 15thDay
15%14%31%26%8%3
90
16th to endDay
9%8%45%27%7%2
96
January1st to 15thNight
8%10%36%34%8%2
900
16th to endNight
10%11%36%31%9%
960
February1st to 15thNight
12%8%38%29%8%
794
16th to endNight
11%7%37%31%9%1
632
March1st to 15thNight
11%7%35%35%9%1
714
16th to endNight
15%8%36%29%9%
576
April1st to 15thNight
17%6%37%32%4
539
16th to endNight
20%7%31%30%8%
540
May1st to 15thNight
14%5%32%34%12%1
540
16th to endNight
14%8%33%33%9%
563
June1st to 15thNight
13%5%32%33%14%
540
16th to endNight
3437%43%11%
540
July1st to 15thNight
6%225%48%17%
510
16th to endNight
2226%54%12%
564
August1st to 15thNight
5%228%49%14%
539
16th to endNight
5%228%43%19%
573
September1st to 15thNight
7%330%40%16%1
540
16th to endNight
9%6%31%35%15%1
516
October1st to 15thNight
17%6%29%33%12%
533
16th to endNight
12%8%26%37%14%
880
November1st to 15thNight
10%8%34%34%10%1
875
16th to endNight
8%8%35%34%13%
900
December1st to 15thNight
10%10%34%34%9%
900
16th to endNight
12%9%33%34%10%
960
Page generated at 2017-09-24 07:15:54. Version ac04

Copyright 2017 A. Danko


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