Morristown
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Morristown clear sky chart from 2005-11-05 to 2017-12-02.

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
77%
16021
38%
47839
33%
15983
82%
15983
57%
22150

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
73%
718
35%
2327
34%
716
78%
716
48%
1112
January16th to endNight
66%
768
38%
2496
36%
768
74%
768
45%
1233
February1st to 15thNight
71%
697
38%
2151
36%
697
80%
697
54%
1004
February16th to endNight
69%
632
36%
1895
37%
632
73%
632
46%
969
March1st to 15thNight
69%
720
40%
2001
33%
720
77%
720
58%
974
March16th to endNight
73%
768
40%
2112
31%
768
81%
768
63%
984
April1st to 15thNight
69%
719
33%
1978
21%
719
76%
719
58%
974
April16th to endNight
70%
557
47%
1658
34%
557
79%
557
73%
662
May1st to 15thNight
76%
539
39%
1619
32%
539
80%
539
66%
681
May16th to endNight
81%
561
40%
1684
32%
561
85%
561
73%
679
June1st to 15thNight
84%
540
35%
1620
30%
540
86%
540
74%
648
June16th to endNight
93%
540
36%
1620
33%
540
93%
540
78%
632
July1st to 15thNight
87%
510
27%
1530
24%
510
87%
510
54%
738
July16th to endNight
85%
564
29%
1593
24%
531
86%
531
45%
840
August1st to 15thNight
86%
539
34%
1611
28%
536
86%
536
54%
761
August16th to endNight
83%
689
35%
1881
30%
689
84%
689
52%
999
September1st to 15thNight
83%
720
33%
1980
29%
720
85%
720
54%
1004
September16th to endNight
85%
716
46%
1980
37%
716
89%
716
71%
874
October1st to 15thNight
80%
720
42%
2037
35%
720
84%
720
67%
909
October16th to endNight
84%
768
46%
2304
41%
768
89%
768
68%
976
November1st to 15thNight
81%
760
39%
2365
37%
760
85%
760
61%
1031
November16th to endNight
78%
780
43%
2535
44%
780
83%
780
57%
1109
December1st to 15thNight
74%
728
37%
2366
36%
728
79%
728
49%
1100
December16th to endNight
67%
768
37%
2496
37%
768
71%
768
42%
1257

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
3212212345%70%
48605
Night
3212213345%70%
48035
TransparencyDay
16%2311%25%41%
48300
Night
16%2311%23%42%
47841
SeeingDay
4316%34%31%9%
5764
Night
4110%36%38%7%
16033

By Month

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
5%31232323467%
1611
16th to endDay
8%212213236%65%
1728
February1st to 15thDay
3312212346%67%
1709
16th to endDay
7%312213346%62%
1579
March1st to 15thDay
4212213336%68%
1958
16th to endDay
3212212335%71%
2112
April1st to 15thDay
3112113348%68%
1970
16th to endDay
11112235%79%
2298
May1st to 15thDay
11111214479%
2331
16th to endDay
21111112482%
2429
June1st to 15thDay
1111112384%
2340
16th to endDay
111112384%
2340
July1st to 15thDay
21123235%47%65%
2340
16th to endDay
5%3245%36%6%8%8%46%
2467
August1st to 15thDay
421232445%8%59%
2340
16th to endDay
321232335%6%64%
2316
September1st to 15thDay
421221235%6%66%
1980
16th to endDay
21111111481%
1980
October1st to 15thDay
21111213479%
1923
16th to endDay
111111223478%
1920
November1st to 15thDay
22213335%74%
1821
16th to endDay
5%11112135%72%
1755
December1st to 15thDay
5%313414436%61%
1630
16th to endDay
7%323223245%60%
1728
January1st to 15thNight
5%31331424466%
2327
16th to endNight
8%423213225%63%
2496
February1st to 15thNight
4212212235%69%
2140
16th to endNight
7%213324446%61%
1895
March1st to 15thNight
5%212112345%70%
2001
16th to endNight
41121333473%
2112
April1st to 15thNight
3212223335%69%
1978
16th to endNight
211122383%
1658
May1st to 15thNight
111112236%75%
1619
16th to endNight
2111112383%
1684
June1st to 15thNight
1111112482%
1620
16th to endNight
111112484%
1620
July1st to 15thNight
212325%5%6%8%61%
1620
16th to endNight
2113435%6%7%12%50%
1701
August1st to 15thNight
211232446%10%60%
1620
16th to endNight
12125%3445%7%60%
1881
September1st to 15thNight
221232446%6%62%
1980
16th to endNight
11121222380%
1980
October1st to 15thNight
311221113476%
2037
16th to endNight
111121222478%
2304
November1st to 15thNight
222212345%72%
2365
16th to endNight
42221222473%
2535
December1st to 15thNight
6%212223346%64%
2366
16th to endNight
8%314312335%61%
2496

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
21%2214%26%32%
1612
16th to endDay
21%2317%25%30%
1728
February1st to 15thDay
19%16%14%28%29%
1709
16th to endDay
22%2316%30%24%
1579
March1st to 15thDay
18%119%31%37%
1958
16th to endDay
16%129%32%36%
2112
April1st to 15thDay
15%1210%31%39%
1970
16th to endDay
9%118%25%54%
2298
May1st to 15thDay
9%117%25%53%
2331
16th to endDay
10%17%23%57%
2432
June1st to 15thDay
7%416%69%
2340
16th to endDay
7%11211%75%
2340
July1st to 15thDay
17%46%15%19%36%
2201
16th to endDay
28%7%11%20%18%13%
2312
August1st to 15thDay
21%37%15%21%30%
2325
16th to endDay
18%35%15%28%27%
2316
September1st to 15thDay
18%26%14%24%33%
1980
16th to endDay
10%5%26%56%
1980
October1st to 15thDay
10%1210%25%49%
1923
16th to endDay
10%137%25%50%
1920
November1st to 15thDay
13%2113%30%38%
1821
16th to endDay
15%1111%25%43%
1755
December1st to 15thDay
23%3417%25%25%
1630
16th to endDay
25%3419%29%18%
1728
January1st to 15thNight
22%2311%24%35%
2327
16th to endNight
25%1213%24%32%
2496
February1st to 15thNight
18%1413%23%37%
2151
16th to endNight
23%3311%27%31%
1895
March1st to 15thNight
17%219%24%44%
2001
16th to endNight
15%1210%30%39%
2112
April1st to 15thNight
17%218%27%42%
1978
16th to endNight
8%117%25%56%
1658
May1st to 15thNight
11%126%26%50%
1620
16th to endNight
8%116%20%61%
1685
June1st to 15thNight
8%1315%70%
1620
16th to endNight
7%1138%78%
1620
July1st to 15thNight
18%38%14%16%38%
1530
16th to endNight
22%6%10%22%20%18%
1593
August1st to 15thNight
17%46%20%19%31%
1611
16th to endNight
21%46%13%23%30%
1881
September1st to 15thNight
19%38%16%21%30%
1980
16th to endNight
10%215%20%61%
1980
October1st to 15thNight
12%1210%23%50%
2037
16th to endNight
11%137%17%57%
2304
November1st to 15thNight
14%2110%29%41%
2365
16th to endNight
16%229%23%46%
2535
December1st to 15thNight
21%2414%26%31%
2366
16th to endNight
26%2417%28%21%
2496

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
27%113%43%13%1
90
16th to endDay
9%318%31%25%12%
96
February1st to 15thDay
5%415%39%32%3
224
16th to endDay
10%7%31%32%16%1
238
March1st to 15thDay
5%8%19%35%24%6%
270
16th to endDay
39%27%32%22%4
288
April1st to 15thDay
5%10%26%29%21%6%
269
16th to endDay
212%33%32%14%4
270
May1st to 15thDay
29%26%39%16%5%
288
16th to endDay
3323%36%26%6%
330
June1st to 15thDay
1223%37%28%6%
315
16th to endDay
2110%36%33%15%
315
July1st to 15thDay
115%39%40%11%
305
16th to endDay
41424%43%22%
327
August1st to 15thDay
4329%41%19%
315
16th to endDay
1428%49%15%
332
September1st to 15thDay
6%8%38%39%8%
315
16th to endDay
5%213%37%33%7%
315
October1st to 15thDay
3118%41%29%5%
258
16th to endDay
38%32%44%11%
144
November1st to 15thDay
1113%37%38%7%
135
16th to endDay
9%14%34%33%8%
135
December1st to 15thDay
318%40%41%5%
94
16th to endDay
14%122%34%25%2
96
January1st to 15thNight
7%112%42%28%8%
720
16th to endNight
11%113%37%29%5%
768
February1st to 15thNight
5%213%42%31%4
704
16th to endNight
8%115%45%24%4
632
March1st to 15thNight
6%218%39%27%6%
720
16th to endNight
4215%39%32%6%
768
April1st to 15thNight
4319%43%25%4
719
16th to endNight
1222%45%21%4
557
May1st to 15thNight
2215%44%29%5%
540
16th to endNight
2112%39%39%4
563
June1st to 15thNight
211%45%37%2
540
16th to endNight
340%48%7%
540
July1st to 15thNight
2326%61%6%
510
16th to endNight
1216%67%11%
564
August1st to 15thNight
2220%63%10%
539
16th to endNight
2318%60%15%
689
September1st to 15thNight
315%26%52%10%
720
16th to endNight
27%34%43%11%
716
October1st to 15thNight
3110%40%38%6%
720
16th to endNight
18%35%42%11%
768
November1st to 15thNight
29%40%37%8%
760
16th to endNight
5%10%37%36%9%
780
December1st to 15thNight
7%11%38%35%5%
728
16th to endNight
10%110%41%29%6%
768
Page generated at 2017-12-03 09:16:48. Version ac04

Copyright 2017 A. Danko


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