Trap Pond State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Trap Pond State Park clear sky chart from 2005-11-05 to 2017-04-09.

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
35%
14786
20%
45449
10%
14752
46%
14752
22%
28810

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
24%
717
22%
2482
9%
716
41%
716
18%
1518
January16th to endNight
20%
768
22%
2496
6%
768
39%
768
19%
1558
February1st to 15thNight
21%
702
20%
2243
8%
701
37%
701
18%
1403
February16th to endNight
19%
631
26%
1893
8%
631
41%
631
21%
1182
March1st to 15thNight
22%
720
20%
2079
8%
720
35%
720
21%
1340
March16th to endNight
24%
768
20%
2037
8%
768
34%
768
21%
1373
April1st to 15thNight
23%
694
19%
1736
5%
694
31%
694
24%
1163
April16th to endNight
33%
660
18%
1650
6%
660
38%
660
25%
1112
May1st to 15thNight
31%
540
17%
1530
7%
540
38%
540
20%
1045
May16th to endNight
44%
342
14%
1369
12%
342
50%
342
16%
845
June1st to 15thNight
48%
330
16%
1320
15%
330
55%
330
18%
825
June16th to endNight
50%
330
12%
1320
12%
330
54%
330
18%
797
July1st to 15thNight
56%
310
14%
1240
17%
310
59%
310
19%
757
July16th to endNight
59%
431
15%
1382
12%
402
68%
402
26%
830
August1st to 15thNight
61%
554
18%
1534
12%
551
62%
551
28%
977
August16th to endNight
62%
700
17%
1750
8%
700
64%
700
31%
1160
September1st to 15thNight
55%
660
25%
1650
16%
660
57%
660
32%
1089
September16th to endNight
50%
657
20%
1776
13%
657
56%
657
24%
1184
October1st to 15thNight
46%
660
24%
1980
21%
660
52%
660
25%
1260
October16th to endNight
37%
704
26%
2118
15%
704
51%
704
27%
1285
November1st to 15thNight
33%
700
22%
2277
14%
700
46%
700
24%
1393
November16th to endNight
31%
720
22%
2379
12%
720
44%
720
20%
1465
December1st to 15thNight
24%
720
19%
2520
8%
720
38%
720
15%
1589
December16th to endNight
18%
768
22%
2688
7%
768
37%
768
17%
1660

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%5%2443445%7%42%
45830
Night
13%5%2442445%7%43%
45628
Cloud CoverDay
13%5%2442445%7%43%
45839
Night
14%5%2442445%7%43%
45633
TransparencyDay
39%6%12%22%15%2
45526
Night
39%6%11%22%16%3
45449
SeeingDay
15%15%22%22%16%6%
5178
Night
15%21%23%26%12%1
14792

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%6%344245%36%44%
1453
16th to endDay
17%5%245%33346%42%
1728
February1st to 15thDay
14%6%25%5%24446%42%
1618
16th to endDay
13%8%245%2445%5%42%
1580
March1st to 15thDay
16%5%1442445%6%45%
1868
16th to endDay
16%6%24434345%43%
2187
April1st to 15thDay
14%5%24423347%47%
2076
16th to endDay
14%5%25%413436%47%
1980
May1st to 15thDay
13%6%3442346%8%41%
2099
16th to endDay
12%4145%245%5%8%44%
2394
June1st to 15thDay
13%424435%46%10%39%
2310
16th to endDay
10%3244346%6%11%41%
2310
July1st to 15thDay
10%3344345%6%10%41%
2310
16th to endDay
5%325%6%46%7%8%11%37%
2373
August1st to 15thDay
9%6%25%6%45%6%6%9%37%
2074
16th to endDay
9%426%6%46%5%5%7%41%
2100
September1st to 15thDay
13%4244245%5%7%43%
1980
16th to endDay
16%6%26%445%45%6%37%
1853
October1st to 15thDay
16%6%25%5%24346%42%
1650
16th to endDay
14%5%24313335%51%
1752
November1st to 15thDay
17%42242345%6%45%
1581
16th to endDay
14%324423447%47%
1578
December1st to 15thDay
13%5%35%43445%7%42%
1440
16th to endDay
19%6%35%423336%41%
1536
January1st to 15thNight
15%5%3442445%5%43%
2482
16th to endNight
15%7%24424345%44%
2496
February1st to 15thNight
15%6%35%333445%45%
2242
16th to endNight
14%6%33413445%47%
1893
March1st to 15thNight
16%5%3432345%6%44%
2067
16th to endNight
17%7%35%42235%6%42%
2037
April1st to 15thNight
14%6%2443345%6%44%
1736
16th to endNight
16%42442445%5%45%
1650
May1st to 15thNight
13%7%25%5%246%5%9%38%
1530
16th to endNight
9%6%35%5%345%5%7%43%
1367
June1st to 15thNight
13%425%5%345%5%8%41%
1320
16th to endNight
8%436%5%36%5%6%11%39%
1320
July1st to 15thNight
8%5%25%5%346%6%8%41%
1320
16th to endNight
5%325%7%37%5%7%12%40%
1485
August1st to 15thNight
6%426%5%35%5%7%9%42%
1545
16th to endNight
9%5%25%4335%6%9%44%
1750
September1st to 15thNight
12%6%2442346%7%44%
1650
16th to endNight
15%5%2442445%7%41%
1776
October1st to 15thNight
15%6%25%42335%6%45%
1980
16th to endNight
15%5%23323337%49%
2118
November1st to 15thNight
14%5%35%422335%49%
2277
16th to endNight
13%6%25%42445%6%44%
2379
December1st to 15thNight
16%6%25%42445%6%40%
2520
16th to endNight
18%5%24323346%43%
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
14%6%25%424446%44%
1453
16th to endDay
17%5%25%5%2435%6%42%
1728
February1st to 15thDay
14%6%25%5%34446%42%
1618
16th to endDay
13%7%34424446%42%
1580
March1st to 15thDay
16%5%24423446%45%
1878
16th to endDay
17%5%24423445%44%
2186
April1st to 15thDay
14%5%22424347%48%
2076
16th to endDay
14%6%34323437%47%
1980
May1st to 15thDay
14%6%25%42445%8%41%
2099
16th to endDay
12%41442446%8%44%
2394
June1st to 15thDay
13%424425%46%9%39%
2310
16th to endDay
9%4244246%7%10%42%
2310
July1st to 15thDay
10%4244345%6%11%41%
2310
16th to endDay
6%3246%45%8%8%11%37%
2373
August1st to 15thDay
9%5%25%5%35%5%6%10%37%
2074
16th to endDay
9%425%7%35%5%5%8%42%
2100
September1st to 15thDay
13%425%43446%6%43%
1980
16th to endDay
16%6%26%4345%5%5%37%
1853
October1st to 15thDay
17%5%24433446%42%
1650
16th to endDay
14%424423435%51%
1752
November1st to 15thDay
16%41442435%6%45%
1581
16th to endDay
14%324424347%47%
1578
December1st to 15thDay
13%5%3442445%7%42%
1440
16th to endDay
19%6%35%423335%41%
1536
January1st to 15thNight
15%5%2442445%6%44%
2482
16th to endNight
16%7%24424345%44%
2496
February1st to 15thNight
14%6%34333445%45%
2235
16th to endNight
14%6%24323445%47%
1893
March1st to 15thNight
16%6%2442345%6%44%
2079
16th to endNight
17%6%45%413236%42%
2037
April1st to 15thNight
15%6%3442445%6%43%
1736
16th to endNight
16%423424446%45%
1650
May1st to 15thNight
14%6%35%4335%6%8%38%
1530
16th to endNight
10%6%25%5%35%46%7%42%
1367
June1st to 15thNight
12%5%25%445%45%8%41%
1320
16th to endNight
8%426%5%45%6%6%10%39%
1320
July1st to 15thNight
9%5%25%5%36%5%7%8%41%
1320
16th to endNight
4425%6%36%5%6%11%40%
1485
August1st to 15thNight
7%325%6%345%6%10%43%
1545
16th to endNight
9%5%3443445%10%44%
1750
September1st to 15thNight
12%5%15%5%2435%8%45%
1650
16th to endNight
17%5%145%3345%8%40%
1776
October1st to 15thNight
15%5%24324346%45%
1980
16th to endNight
15%5%23323346%49%
2118
November1st to 15thNight
14%6%24423235%49%
2277
16th to endNight
14%5%3442445%5%45%
2379
December1st to 15thNight
16%6%25%42445%6%40%
2520
16th to endNight
18%5%24423346%44%
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%5%12%21%15%4
1454
16th to endDay
42%310%23%16%2
1728
February1st to 15thDay
42%411%24%14%2
1621
16th to endDay
42%411%24%14%2
1580
March1st to 15thDay
39%5%12%23%16%2
1878
16th to endDay
42%5%9%22%17%3
2187
April1st to 15thDay
36%5%10%24%17%4
2076
16th to endDay
37%5%10%17%21%7%
1980
May1st to 15thDay
40%7%15%22%13%1
2099
16th to endDay
36%7%16%24%13%2
2398
June1st to 15thDay
39%8%14%22%13%1
2310
16th to endDay
34%8%18%20%16%2
2310
July1st to 15thDay
35%9%14%23%14%2
2161
16th to endDay
34%11%17%21%13%1
2213
August1st to 15thDay
39%8%14%23%13%
2061
16th to endDay
38%8%12%19%16%3
2100
September1st to 15thDay
38%7%13%19%18%2
1980
16th to endDay
45%7%8%17%19%1
1853
October1st to 15thDay
42%6%9%23%14%3
1650
16th to endDay
36%37%27%21%2
1752
November1st to 15thDay
38%5%11%24%17%3
1581
16th to endDay
36%5%10%26%16%3
1578
December1st to 15thDay
40%5%14%23%12%3
1440
16th to endDay
44%412%24%13%1
1536
January1st to 15thNight
40%5%11%21%18%3
2482
16th to endNight
41%310%25%15%2
2496
February1st to 15thNight
41%49%25%16%2
2243
16th to endNight
38%5%9%24%20%2
1893
March1st to 15thNight
40%411%25%15%2
2079
16th to endNight
44%410%18%18%3
2037
April1st to 15thNight
39%5%11%20%18%4
1736
16th to endNight
40%5%9%18%21%6%
1650
May1st to 15thNight
42%7%13%20%14%2
1530
16th to endNight
39%9%15%19%14%1
1369
June1st to 15thNight
40%8%13%20%16%1
1320
16th to endNight
37%10%15%19%16%1
1320
July1st to 15thNight
38%9%15%20%13%2
1240
16th to endNight
34%9%17%24%13%1
1382
August1st to 15thNight
34%9%16%21%18%
1534
16th to endNight
34%9%14%19%19%2
1750
September1st to 15thNight
37%6%14%22%16%3
1650
16th to endNight
40%7%10%19%18%3
1776
October1st to 15thNight
39%5%9%25%16%3
1980
16th to endNight
36%49%24%20%3
2118
November1st to 15thNight
38%49%21%18%6%
2277
16th to endNight
39%5%10%22%17%4
2379
December1st to 15thNight
43%5%11%23%12%2
2520
16th to endNight
41%413%22%14%3
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
17%17%42%15%6%
63
16th to endDay
30%14%35%15%4
96
February1st to 15thDay
20%26%35%12%4
134
16th to endDay
14%23%38%18%4
239
March1st to 15thDay
17%23%26%24%7%
270
16th to endDay
18%21%31%19%43
288
April1st to 15thDay
17%24%27%20%8%1
245
16th to endDay
16%20%25%20%12%4
210
May1st to 15thDay
26%19%22%14%14%2
228
16th to endDay
16%14%16%22%21%8%
267
June1st to 15thDay
16%13%21%26%17%4
255
16th to endDay
12%15%16%30%18%7%
255
July1st to 15thDay
13%9%11%26%28%11%
245
16th to endDay
411%9%31%27%15%
270
August1st to 15thDay
8%10%11%27%28%13%
253
16th to endDay
7%6%8%25%34%18%
268
September1st to 15thDay
12%7%17%21%21%19%
255
16th to endDay
23%9%15%21%16%13%
254
October1st to 15thDay
18%9%22%23%20%6%
255
16th to endDay
12%13%30%21%19%2
271
November1st to 15thDay
17%16%22%22%17%3
235
16th to endDay
13%24%24%21%12%2
198
December1st to 15thDay
16%20%26%20%15%1
60
16th to endDay
37%9%35%10%6%
64
January1st to 15thNight
14%28%27%24%5%
720
16th to endNight
18%24%32%22%2
768
February1st to 15thNight
17%27%30%23%1
704
16th to endNight
16%28%32%20%2
631
March1st to 15thNight
19%26%30%19%5%
720
16th to endNight
18%24%29%19%6%1
768
April1st to 15thNight
16%25%31%21%4
694
16th to endNight
16%23%23%26%8%
660
May1st to 15thNight
16%22%27%22%10%
540
16th to endNight
11%20%18%34%14%
343
June1st to 15thNight
11%19%15%36%15%
330
16th to endNight
5%19%15%40%18%
330
July1st to 15thNight
7%13%13%41%22%
310
16th to endNight
317%11%37%27%2
431
August1st to 15thNight
9%10%8%42%25%3
554
16th to endNight
10%9%10%32%31%4
700
September1st to 15thNight
14%10%12%29%30%2
660
16th to endNight
18%11%12%32%21%3
657
October1st to 15thNight
16%12%18%30%19%1
660
16th to endNight
17%16%26%24%13%1
704
November1st to 15thNight
15%20%24%24%12%2
700
16th to endNight
14%26%23%25%9%
720
December1st to 15thNight
18%25%26%18%9%1
720
16th to endNight
18%27%32%18%3
768
Page generated at 2017-04-10 09:00:35. Version ac04

Copyright 2017 A. Danko


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