Jonesport
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Jonesport clear sky chart from 2005-11-05 to 2017-09-18.

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
26%
14881
15%
46799
7%
14843
36%
14843
16%
32566

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%
727
15%
2547
4%
723
28%
723
11%
1740
January16th to endNight
12%
768
14%
2610
2%
768
26%
768
10%
1823
February1st to 15thNight
12%
703
11%
2286
3%
701
22%
701
10%
1634
February16th to endNight
17%
631
16%
1925
4%
631
31%
631
13%
1345
March1st to 15thNight
18%
720
16%
2061
6%
720
29%
720
14%
1498
March16th to endNight
23%
768
18%
2112
7%
768
33%
768
18%
1483
April1st to 15thNight
21%
641
16%
1776
4%
641
30%
641
17%
1293
April16th to endNight
27%
540
14%
1620
5%
540
35%
540
17%
1152
May1st to 15thNight
28%
540
13%
1620
7%
540
34%
540
15%
1192
May16th to endNight
29%
518
10%
1518
6%
517
35%
517
15%
1132
June1st to 15thNight
31%
360
8%
1260
7%
360
36%
360
11%
969
June16th to endNight
33%
360
10%
1260
7%
360
38%
360
12%
922
July1st to 15thNight
43%
340
10%
1240
13%
340
45%
340
16%
828
July16th to endNight
37%
442
10%
1479
11%
415
42%
415
14%
1049
August1st to 15thNight
47%
539
10%
1608
8%
535
49%
535
18%
1141
August16th to endNight
52%
573
18%
1719
12%
573
55%
573
23%
1137
September1st to 15thNight
47%
675
17%
1905
12%
675
51%
675
28%
1230
September16th to endNight
42%
669
26%
1847
14%
669
52%
669
32%
1133
October1st to 15thNight
33%
660
20%
1928
10%
660
43%
660
22%
1269
October16th to endNight
24%
704
19%
2200
8%
704
36%
704
20%
1455
November1st to 15thNight
31%
703
18%
2295
11%
703
40%
703
18%
1529
November16th to endNight
20%
750
15%
2520
5%
750
33%
750
13%
1731
December1st to 15thNight
14%
750
13%
2583
3%
750
26%
750
11%
1841
December16th to endNight
12%
800
14%
2880
3%
800
26%
800
10%
2040

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
20%8%25%42445%7%35%
47995
Night
21%8%35%42445%6%33%
46971
TransparencyDay
48%411%21%12%1
47685
Night
51%410%20%12%1
46799
SeeingDay
24%14%21%24%12%2
6655
Night
22%21%21%21%10%1
14882

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
17%7%46%3235%5%8%33%
1388
16th to endDay
17%10%45%42445%7%31%
1614
February1st to 15thDay
17%11%346%346%6%9%25%
1575
16th to endDay
14%10%36%5%25%6%6%7%32%
1548
March1st to 15thDay
20%10%35%5%24346%33%
1888
16th to endDay
17%8%25%5%24446%39%
2112
April1st to 15thDay
21%7%25%32345%6%36%
2170
16th to endDay
21%6%25%5%2345%6%36%
2340
May1st to 15thDay
25%7%25%5%23446%30%
2332
16th to endDay
25%8%3432345%6%31%
2604
June1st to 15thDay
27%8%35%5%34446%27%
2700
16th to endDay
25%8%35%424446%30%
2700
July1st to 15thDay
19%7%25%42447%8%32%
2643
16th to endDay
18%9%26%425%46%7%31%
2574
August1st to 15thDay
18%7%25%42445%7%35%
2340
16th to endDay
14%6%2342445%8%42%
2483
September1st to 15thDay
16%5%13323447%46%
2052
16th to endDay
16%7%14322335%48%
1838
October1st to 15thDay
18%6%24424437%41%
1701
16th to endDay
21%6%2433235%6%38%
1672
November1st to 15thDay
21%6%25%423346%38%
1563
16th to endDay
22%7%25%5%23435%36%
1440
December1st to 15thDay
27%8%25%32235%7%30%
1374
16th to endDay
28%7%34433346%31%
1344
January1st to 15thNight
18%9%26%6%34447%32%
2547
16th to endNight
16%11%36%4346%6%8%27%
2610
February1st to 15thNight
18%9%36%5%25%6%6%8%27%
2285
16th to endNight
16%9%45%5%2445%6%34%
1925
March1st to 15thNight
20%11%46%423445%32%
2049
16th to endNight
18%7%36%5%24446%36%
2112
April1st to 15thNight
24%9%24425%45%6%30%
1776
16th to endNight
23%8%45%42335%5%32%
1620
May1st to 15thNight
24%9%36%423436%30%
1620
16th to endNight
28%8%25%42436%5%28%
1516
June1st to 15thNight
32%10%25%423348%21%
1260
16th to endNight
27%8%26%424336%28%
1260
July1st to 15thNight
22%8%26%42445%8%30%
1314
16th to endNight
24%10%35%42445%7%27%
1580
August1st to 15thNight
20%8%246%25%5%6%7%30%
1620
16th to endNight
18%5%24425%446%39%
1719
September1st to 15thNight
18%6%33313447%43%
1905
16th to endNight
15%6%23313345%51%
1847
October1st to 15thNight
21%5%24423345%41%
1928
16th to endNight
21%7%24423436%40%
2200
November1st to 15thNight
20%6%25%5%2345%6%37%
2295
16th to endNight
20%7%344245%5%6%35%
2520
December1st to 15thNight
26%9%35%423348%28%
2583
16th to endNight
25%8%35%42435%6%30%
2880

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
48%415%18%10%2
1389
16th to endDay
51%313%21%8%
1614
February1st to 15thDay
54%5%12%16%9%1
1578
16th to endDay
48%5%12%20%11%1
1548
March1st to 15thDay
52%48%19%12%2
1899
16th to endDay
46%49%18%17%3
2112
April1st to 15thDay
47%38%20%16%2
2170
16th to endDay
48%410%18%14%3
2340
May1st to 15thDay
54%38%17%14%1
2332
16th to endDay
52%410%22%7%1
2608
June1st to 15thDay
57%5%9%17%8%1
2700
16th to endDay
55%48%18%12%1
2700
July1st to 15thDay
47%5%11%24%10%
2488
16th to endDay
49%5%13%22%8%
2413
August1st to 15thDay
46%5%12%24%10%
2327
16th to endDay
39%413%25%16%
2483
September1st to 15thDay
37%412%26%17%2
2052
16th to endDay
38%37%30%18%1
1838
October1st to 15thDay
43%39%26%15%
1701
16th to endDay
46%312%25%11%
1672
November1st to 15thDay
46%412%22%13%
1563
16th to endDay
52%312%18%12%1
1440
December1st to 15thDay
54%413%18%9%
1374
16th to endDay
56%310%18%11%
1344
January1st to 15thNight
52%312%20%9%1
2547
16th to endNight
53%412%19%8%
2610
February1st to 15thNight
53%5%13%16%10%1
2286
16th to endNight
50%5%11%18%13%2
1925
March1st to 15thNight
54%38%17%13%1
2061
16th to endNight
49%38%19%17%2
2112
April1st to 15thNight
52%48%15%15%2
1776
16th to endNight
52%48%17%14%3
1620
May1st to 15thNight
55%47%18%13%1
1620
16th to endNight
56%410%19%8%
1518
June1st to 15thNight
62%39%15%6%1
1260
16th to endNight
58%46%20%10%
1260
July1st to 15thNight
50%413%19%12%
1240
16th to endNight
54%411%20%7%1
1479
August1st to 15thNight
51%5%12%21%9%
1608
16th to endNight
43%5%11%24%14%
1719
September1st to 15thNight
41%311%26%16%
1905
16th to endNight
35%47%31%22%
1847
October1st to 15thNight
45%29%25%15%1
1928
16th to endNight
46%39%26%13%
2200
November1st to 15thNight
48%312%21%13%1
2295
16th to endNight
50%412%18%12%1
2520
December1st to 15thNight
54%410%20%9%
2583
16th to endNight
55%310%18%11%
2880

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
20%16%30%30%3
60
16th to endDay
26%18%33%15%6%
142
February1st to 15thDay
22%25%28%17%5%
236
16th to endDay
20%17%32%23%5%
234
March1st to 15thDay
23%22%28%19%4
270
16th to endDay
24%20%24%23%6%1
288
April1st to 15thDay
28%18%29%15%6%2
270
16th to endDay
21%16%30%20%9%2
270
May1st to 15thDay
30%13%23%22%7%2
288
16th to endDay
30%13%20%22%11%2
450
June1st to 15thDay
24%14%17%29%13%1
495
16th to endDay
29%13%14%24%14%2
495
July1st to 15thDay
26%10%11%30%19%1
422
16th to endDay
22%11%12%29%21%2
326
August1st to 15thDay
20%8%12%31%21%4
313
16th to endDay
18%6%14%31%24%5%
332
September1st to 15thDay
20%7%18%29%20%3
315
16th to endDay
19%8%17%29%19%5%
262
October1st to 15thDay
22%13%23%19%17%3
234
16th to endDay
24%13%28%22%10%
240
November1st to 15thDay
20%19%22%23%10%2
235
16th to endDay
22%23%25%17%8%1
240
December1st to 15thDay
27%16%28%20%5%
174
16th to endDay
42%10%31%14%1
64
January1st to 15thNight
19%31%27%16%4
727
16th to endNight
19%32%29%15%3
768
February1st to 15thNight
20%30%30%15%2
704
16th to endNight
20%28%28%17%3
631
March1st to 15thNight
24%26%24%19%3
720
16th to endNight
18%26%26%20%7%
768
April1st to 15thNight
24%21%28%19%6%
641
16th to endNight
21%20%21%24%10%1
540
May1st to 15thNight
24%18%19%23%11%2
540
16th to endNight
27%20%13%24%12%2
518
June1st to 15thNight
28%18%10%27%13%1
360
16th to endNight
27%17%9%28%14%2
360
July1st to 15thNight
27%14%6%28%20%2
340
16th to endNight
25%16%6%26%21%2
442
August1st to 15thNight
24%10%6%30%24%3
539
16th to endNight
19%9%7%30%26%5%
573
September1st to 15thNight
20%10%13%32%19%3
675
16th to endNight
18%11%20%23%19%5%
669
October1st to 15thNight
23%14%21%23%14%3
660
16th to endNight
23%16%29%22%7%
704
November1st to 15thNight
20%19%22%24%11%2
703
16th to endNight
20%26%26%16%8%
750
December1st to 15thNight
29%24%24%15%5%
750
16th to endNight
28%28%26%14%2
800
Page generated at 2017-09-19 07:32:26. Version ac04

Copyright 2017 A. Danko


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