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 2017-03-24.

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%
15142
38%
45256
33%
15104
82%
15104
57%
21001

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
74%
740
39%
2035
30%
740
81%
740
62%
951
April1st to 15thNight
67%
659
34%
1813
22%
659
75%
659
56%
906
April16th to endNight
71%
511
44%
1520
32%
511
79%
511
72%
613
May1st to 15thNight
75%
494
41%
1484
33%
494
80%
494
67%
619
May16th to endNight
81%
513
38%
1540
30%
513
84%
513
72%
626
June1st to 15thNight
84%
495
37%
1485
32%
495
86%
495
74%
597
June16th to endNight
93%
495
34%
1485
31%
495
93%
495
78%
578
July1st to 15thNight
87%
465
28%
1395
25%
465
87%
465
53%
677
July16th to endNight
86%
522
30%
1467
25%
489
87%
489
48%
754
August1st to 15thNight
87%
494
36%
1476
29%
491
87%
491
56%
687
August16th to endNight
83%
631
33%
1723
28%
631
83%
631
51%
922
September1st to 15thNight
83%
660
34%
1815
29%
660
85%
660
54%
923
September16th to endNight
85%
656
43%
1815
35%
656
89%
656
70%
807
October1st to 15thNight
78%
660
43%
1867
35%
660
83%
660
65%
849
October16th to endNight
84%
704
44%
2112
38%
704
89%
704
66%
906
November1st to 15thNight
82%
700
41%
2178
39%
700
86%
700
63%
927
November16th to endNight
77%
720
41%
2340
41%
720
82%
720
56%
1028
December1st to 15thNight
74%
720
37%
2340
36%
720
79%
720
50%
1082
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%
45672
Night
3212213335%69%
45452
TransparencyDay
16%2311%25%40%
45367
Night
17%2311%23%42%
45258
SeeingDay
5%417%35%29%7%
4815
Night
4111%37%38%7%
15154

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%
2033
April1st to 15thDay
3112113337%68%
1805
16th to endDay
1111223479%
2106
May1st to 15thDay
11111214479%
2136
16th to endDay
22111112481%
2221
June1st to 15thDay
1111112383%
2145
16th to endDay
111112383%
2145
July1st to 15thDay
22123235%47%63%
2145
16th to endDay
5%3145%36%6%7%8%47%
2285
August1st to 15thDay
421222445%8%60%
2145
16th to endDay
421232345%6%63%
2122
September1st to 15thDay
5%31221235%6%66%
1815
16th to endDay
21111122480%
1815
October1st to 15thDay
211112135%78%
1763
16th to endDay
111111223478%
1760
November1st to 15thDay
22212335%75%
1678
16th to endDay
5%1122135%73%
1620
December1st to 15thDay
5%313414436%62%
1620
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
411121333472%
2035
April1st to 15thNight
3212323335%68%
1813
16th to endNight
211122283%
1520
May1st to 15thNight
112112237%75%
1484
16th to endNight
2111111383%
1540
June1st to 15thNight
211222382%
1485
16th to endNight
111112384%
1485
July1st to 15thNight
2113325%5%6%8%60%
1485
16th to endNight
2113325%6%7%11%52%
1575
August1st to 15thNight
211332446%10%61%
1485
16th to endNight
12125%35%45%7%60%
1723
September1st to 15thNight
221232446%5%62%
1815
16th to endNight
11121222480%
1815
October1st to 15thNight
3112212245%74%
1867
16th to endNight
111121223477%
2112
November1st to 15thNight
21221233474%
2178
16th to endNight
42221222473%
2340
December1st to 15thNight
6%212223346%65%
2340
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
17%129%31%37%
2033
April1st to 15thDay
15%1210%30%39%
1805
16th to endDay
10%118%24%54%
2106
May1st to 15thDay
9%117%26%54%
2136
16th to endDay
10%16%24%55%
2224
June1st to 15thDay
8%1415%69%
2145
16th to endDay
8%11211%74%
2145
July1st to 15thDay
18%46%14%20%35%
2006
16th to endDay
27%7%10%20%20%15%
2130
August1st to 15thDay
21%37%16%21%30%
2130
16th to endDay
19%36%16%29%23%
2122
September1st to 15thDay
19%26%14%23%34%
1815
16th to endDay
10%5%25%56%
1815
October1st to 15thDay
11%1211%26%45%
1763
16th to endDay
10%148%26%49%
1760
November1st to 15thDay
12%2111%31%40%
1678
16th to endDay
15%1112%25%44%
1620
December1st to 15thDay
23%2417%25%26%
1620
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%129%30%39%
2035
April1st to 15thNight
18%218%27%40%
1813
16th to endNight
8%117%25%55%
1520
May1st to 15thNight
10%126%27%51%
1485
16th to endNight
9%115%21%60%
1541
June1st to 15thNight
8%1314%70%
1485
16th to endNight
7%1138%78%
1485
July1st to 15thNight
18%38%14%16%37%
1395
16th to endNight
20%6%9%22%21%19%
1467
August1st to 15thNight
16%47%20%19%31%
1476
16th to endNight
21%47%14%23%28%
1723
September1st to 15thNight
19%38%15%21%31%
1815
16th to endNight
10%215%20%59%
1815
October1st to 15thNight
13%1211%24%46%
1867
16th to endNight
12%138%18%55%
2112
November1st to 15thNight
13%218%29%44%
2178
16th to endNight
16%229%22%46%
2340
December1st to 15thNight
20%2414%26%31%
2340
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
38%26%33%23%4
260
April1st to 15thDay
6%12%28%31%17%3
209
16th to endDay
214%34%32%12%3
210
May1st to 15thDay
210%25%40%15%4
228
16th to endDay
4322%36%26%6%
266
June1st to 15thDay
2327%35%25%6%
255
16th to endDay
2112%39%30%13%
255
July1st to 15thDay
126%43%38%7%
245
16th to endDay
415%26%43%18%
271
August1st to 15thDay
3332%41%18%
255
16th to endDay
1430%48%13%
268
September1st to 15thDay
7%7%40%38%5%
255
16th to endDay
6%313%37%30%8%
255
October1st to 15thDay
3220%37%30%5%
203
16th to endDay
39%34%51%2
96
November1st to 15thDay
1213%33%38%11%
90
16th to endDay
7%116%44%26%3
90
December1st to 15thDay
318%40%41%5%
90
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
4214%40%32%6%
740
April1st to 15thNight
4319%44%23%4
659
16th to endNight
2221%47%21%4
511
May1st to 15thNight
2215%44%29%5%
495
16th to endNight
212%40%38%4
515
June1st to 15thNight
210%45%37%2
495
16th to endNight
340%48%7%
495
July1st to 15thNight
2326%61%6%
465
16th to endNight
1216%68%10%
522
August1st to 15thNight
2221%63%10%
494
16th to endNight
2319%59%14%
631
September1st to 15thNight
316%25%53%10%
660
16th to endNight
218%32%43%11%
656
October1st to 15thNight
3110%38%38%6%
660
16th to endNight
28%36%41%10%
704
November1st to 15thNight
210%39%38%9%
700
16th to endNight
5%10%37%35%9%
720
December1st to 15thNight
7%11%38%35%5%
720
16th to endNight
10%110%41%29%6%
768
Page generated at 2017-03-25 09:39:53. Version ac04

Copyright 2017 A. Danko


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