Belleplain State Forest
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Belleplain State Forest clear sky chart from 2005-11-05 to 2017-08-12.

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
36%
15034
20%
46492
10%
15000
46%
15000
23%
29578

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
22%
720
21%
2506
8%
716
39%
716
17%
1570
January16th to endNight
17%
768
21%
2520
6%
768
36%
768
19%
1565
February1st to 15thNight
17%
704
19%
2228
6%
701
33%
701
19%
1397
February16th to endNight
20%
631
26%
1893
8%
631
43%
631
21%
1181
March1st to 15thNight
24%
720
20%
2112
9%
720
38%
720
24%
1331
March16th to endNight
26%
768
21%
2017
9%
768
35%
768
24%
1371
April1st to 15thNight
27%
718
18%
1796
5%
718
34%
718
27%
1195
April16th to endNight
37%
720
17%
1800
7%
720
40%
720
27%
1241
May1st to 15thNight
33%
556
16%
1636
8%
556
38%
556
21%
1136
May16th to endNight
49%
374
14%
1497
13%
374
54%
374
18%
962
June1st to 15thNight
50%
360
15%
1440
16%
360
56%
360
21%
897
June16th to endNight
61%
360
16%
1440
20%
360
66%
360
24%
845
July1st to 15thNight
61%
340
12%
1360
15%
340
62%
340
19%
858
July16th to endNight
65%
407
15%
1447
15%
383
69%
383
25%
843
August1st to 15thNight
67%
599
17%
1647
12%
596
67%
596
33%
1059
August16th to endNight
62%
700
17%
1750
9%
700
63%
700
33%
1168
September1st to 15thNight
58%
660
25%
1650
15%
660
62%
660
33%
1095
September16th to endNight
52%
657
21%
1788
16%
657
55%
657
30%
1144
October1st to 15thNight
46%
660
23%
1955
18%
660
54%
660
28%
1224
October16th to endNight
35%
704
25%
2152
15%
704
50%
704
26%
1293
November1st to 15thNight
33%
700
22%
2277
13%
700
47%
700
23%
1379
November16th to endNight
29%
720
20%
2373
11%
720
42%
720
19%
1515
December1st to 15thNight
22%
720
17%
2520
7%
720
35%
720
15%
1631
December16th to endNight
19%
768
21%
2688
7%
768
38%
768
17%
1678

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%2442445%8%42%
47473
Night
14%5%2442445%7%43%
46665
Cloud CoverDay
13%5%2442445%8%42%
47482
Night
14%5%25%42445%7%43%
46671
TransparencyDay
38%7%12%23%15%2
47164
Night
40%6%11%22%16%2
46492
SeeingDay
17%9%26%28%15%3
5672
Night
17%11%28%27%13%1
15035

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%35%32436%6%43%
1432
16th to endDay
15%7%34323445%44%
1701
February1st to 15thDay
14%7%25%42435%6%42%
1631
16th to endDay
12%8%37%43425%5%41%
1580
March1st to 15thDay
16%5%24424346%44%
1835
16th to endDay
16%7%2432435%5%43%
2206
April1st to 15thDay
16%5%33324446%45%
2152
16th to endDay
13%5%2442445%8%43%
2160
May1st to 15thDay
15%6%234245%5%9%38%
2323
16th to endDay
12%5%244245%5%9%43%
2618
June1st to 15thDay
11%5%25%425%6%6%9%39%
2520
16th to endDay
10%4144346%6%11%42%
2520
July1st to 15thDay
8%5%245%345%7%10%41%
2520
16th to endDay
7%425%6%36%7%7%11%37%
2620
August1st to 15thDay
9%425%4345%5%9%44%
2203
16th to endDay
10%414425%5%7%9%42%
2100
September1st to 15thDay
13%425%32346%8%44%
1980
16th to endDay
14%6%25%5%2346%7%39%
1840
October1st to 15thDay
15%5%2342435%6%45%
1672
16th to endDay
15%425%423235%49%
1719
November1st to 15thDay
17%6%34323347%44%
1581
16th to endDay
14%424324447%46%
1584
December1st to 15thDay
15%6%25%425%437%40%
1440
16th to endDay
20%7%24313346%41%
1536
January1st to 15thNight
16%5%34425%45%6%42%
2506
16th to endNight
16%6%24423446%43%
2520
February1st to 15thNight
15%6%25%433346%43%
2227
16th to endNight
15%5%2342435%5%47%
1893
March1st to 15thNight
16%6%23413337%47%
2099
16th to endNight
17%7%34424335%42%
2017
April1st to 15thNight
15%6%25%324446%43%
1796
16th to endNight
17%5%25%43445%7%41%
1800
May1st to 15thNight
15%8%36%5%35%45%6%36%
1636
16th to endNight
14%6%35%5%36%447%37%
1495
June1st to 15thNight
13%5%35%435%45%8%41%
1440
16th to endNight
8%425%5%345%6%10%42%
1440
July1st to 15thNight
7%426%6%37%6%6%7%39%
1440
16th to endNight
6%426%5%36%6%6%10%40%
1545
August1st to 15thNight
6%4246%35%5%6%8%44%
1658
16th to endNight
10%425%4245%6%8%45%
1750
September1st to 15thNight
12%5%24423448%46%
1650
16th to endNight
15%6%2332445%7%44%
1788
October1st to 15thNight
16%424423347%46%
1955
16th to endNight
14%5%24323346%49%
2152
November1st to 15thNight
15%7%24323235%49%
2277
16th to endNight
14%5%35%5%345%47%41%
2373
December1st to 15thNight
17%6%25%5%2445%7%38%
2520
16th to endNight
17%5%3442435%6%41%
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
13%7%25%42445%6%43%
1432
16th to endDay
16%7%24414445%44%
1701
February1st to 15thDay
14%8%25%42335%6%43%
1631
16th to endDay
12%8%36%5%3425%5%41%
1580
March1st to 15thDay
16%424424446%43%
1845
16th to endDay
16%7%2442435%6%42%
2205
April1st to 15thDay
15%5%24324446%45%
2152
16th to endDay
13%5%244245%6%8%43%
2160
May1st to 15thDay
15%6%244345%5%8%39%
2323
16th to endDay
12%5%245%3445%8%43%
2618
June1st to 15thDay
11%5%25%425%5%6%10%39%
2520
16th to endDay
10%423335%6%6%11%43%
2520
July1st to 15thDay
8%5%244345%7%10%41%
2520
16th to endDay
7%4246%36%7%7%11%37%
2620
August1st to 15thDay
9%5%15%5%345%5%9%45%
2203
16th to endDay
10%5%24425%6%7%9%42%
2100
September1st to 15thDay
13%4244235%5%8%45%
1980
16th to endDay
14%7%25%43446%8%38%
1840
October1st to 15thDay
15%5%2441435%6%45%
1672
16th to endDay
15%425%423335%49%
1719
November1st to 15thDay
17%6%23323347%44%
1581
16th to endDay
15%424424447%46%
1584
December1st to 15thDay
15%6%25%425%437%40%
1440
16th to endDay
20%7%14322346%41%
1536
January1st to 15thNight
16%5%3442445%6%42%
2506
16th to endNight
16%7%24423447%43%
2520
February1st to 15thNight
15%6%25%423445%44%
2220
16th to endNight
15%5%2432345%5%47%
1893
March1st to 15thNight
16%6%23423337%46%
2112
16th to endNight
17%7%35%42334442%
2017
April1st to 15thNight
15%6%34423437%43%
1796
16th to endNight
17%5%15%42435%6%41%
1800
May1st to 15thNight
16%8%26%44445%6%35%
1636
16th to endNight
15%6%26%5%45%45%7%37%
1495
June1st to 15thNight
13%5%34425%45%8%40%
1440
16th to endNight
8%425%5%45%6%5%11%41%
1440
July1st to 15thNight
7%426%7%36%6%7%7%39%
1440
16th to endNight
6%5%25%5%36%5%7%10%40%
1545
August1st to 15thNight
6%4245%45%5%6%8%44%
1658
16th to endNight
9%5%244246%5%7%45%
1750
September1st to 15thNight
13%4245%235%48%45%
1650
16th to endNight
15%6%2341345%7%43%
1788
October1st to 15thNight
16%424423346%46%
1955
16th to endNight
14%5%24323346%49%
2152
November1st to 15thNight
15%7%24323235%49%
2277
16th to endNight
14%5%35%5%335%5%7%41%
2373
December1st to 15thNight
17%6%25%5%23446%39%
2520
16th to endNight
18%5%2442445%6%41%
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%416%21%13%3
1433
16th to endDay
40%410%24%16%3
1701
February1st to 15thDay
41%313%25%13%2
1634
16th to endDay
42%410%27%12%2
1580
March1st to 15thDay
40%5%12%24%15%2
1845
16th to endDay
41%6%9%22%17%3
2206
April1st to 15thDay
38%5%10%23%16%4
2152
16th to endDay
37%7%11%16%21%4
2160
May1st to 15thDay
40%6%14%21%14%1
2323
16th to endDay
37%8%14%25%12%1
2622
June1st to 15thDay
36%12%13%24%11%1
2520
16th to endDay
32%10%15%23%16%1
2520
July1st to 15thDay
34%8%14%25%15%2
2371
16th to endDay
34%10%14%24%14%1
2455
August1st to 15thDay
34%7%13%26%16%1
2190
16th to endDay
32%8%14%22%18%3
2100
September1st to 15thDay
34%7%13%22%19%2
1980
16th to endDay
42%7%10%15%21%1
1840
October1st to 15thDay
38%5%12%25%15%2
1672
16th to endDay
37%410%27%19%1
1719
November1st to 15thDay
40%312%24%16%2
1581
16th to endDay
37%5%11%26%15%3
1584
December1st to 15thDay
43%5%16%19%12%2
1440
16th to endDay
43%413%25%12%1
1536
January1st to 15thNight
42%5%11%21%16%3
2506
16th to endNight
41%411%25%15%1
2520
February1st to 15thNight
42%311%25%15%2
2228
16th to endNight
38%5%9%23%19%3
1893
March1st to 15thNight
39%412%23%16%3
2112
16th to endNight
44%410%19%17%3
2017
April1st to 15thNight
40%5%10%21%17%4
1796
16th to endNight
42%5%9%16%22%4
1800
May1st to 15thNight
47%6%8%20%14%2
1636
16th to endNight
44%7%13%18%13%1
1497
June1st to 15thNight
41%7%12%21%16%
1440
16th to endNight
35%8%12%27%13%2
1440
July1st to 15thNight
40%10%15%19%12%2
1360
16th to endNight
33%9%17%23%14%1
1447
August1st to 15thNight
33%9%15%22%17%1
1647
16th to endNight
35%8%12%21%19%2
1750
September1st to 15thNight
36%7%11%22%18%2
1650
16th to endNight
38%5%11%20%21%2
1788
October1st to 15thNight
39%412%24%17%2
1955
16th to endNight
36%410%27%17%2
2152
November1st to 15thNight
38%410%21%18%6%
2277
16th to endNight
41%6%11%22%15%3
2373
December1st to 15thNight
45%6%12%21%12%1
2520
16th to endNight
41%5%14%22%14%2
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
13%25%41%15%31
60
16th to endDay
23%19%37%18%1
91
February1st to 15thDay
25%25%33%14%2
147
16th to endDay
14%23%41%18%2
239
March1st to 15thDay
19%21%28%25%5%
270
16th to endDay
18%15%37%22%32
288
April1st to 15thDay
20%12%35%22%7%1
270
16th to endDay
22%7%28%29%10%1
270
May1st to 15thDay
29%10%30%18%9%1
288
16th to endDay
16%5%20%34%18%4
331
June1st to 15thDay
15%427%31%17%3
315
16th to endDay
14%126%37%18%1
315
July1st to 15thDay
12%119%40%20%4
305
16th to endDay
7%315%38%28%5%
326
August1st to 15thDay
12%116%36%27%7%
297
16th to endDay
11%10%33%30%14%
268
September1st to 15thDay
14%319%27%22%12%
255
16th to endDay
21%320%30%14%9%
254
October1st to 15thDay
20%322%29%19%4
255
16th to endDay
15%16%27%24%13%1
265
November1st to 15thDay
20%11%28%22%15%1
235
16th to endDay
17%19%29%19%12%1
204
December1st to 15thDay
18%18%28%23%11%
60
16th to endDay
35%18%31%14%
64
January1st to 15thNight
19%21%32%21%5%
720
16th to endNight
20%21%38%18%1
768
February1st to 15thNight
19%20%37%21%1
704
16th to endNight
18%22%35%20%2
631
March1st to 15thNight
20%16%34%22%5%
720
16th to endNight
21%12%34%22%7%1
768
April1st to 15thNight
18%12%38%23%5%
718
16th to endNight
20%6%30%32%9%
720
May1st to 15thNight
20%7%33%29%9%
556
16th to endNight
17%219%37%20%1
375
June1st to 15thNight
16%222%36%20%1
360
16th to endNight
8%120%46%22%1
360
July1st to 15thNight
8%116%48%23%2
340
16th to endNight
8%112%44%30%2
407
August1st to 15thNight
9%113%46%26%2
599
16th to endNight
13%113%35%31%4
700
September1st to 15thNight
15%117%33%27%4
660
16th to endNight
18%218%30%25%3
657
October1st to 15thNight
20%6%22%30%17%3
660
16th to endNight
18%13%29%23%14%
704
November1st to 15thNight
19%15%28%22%12%2
700
16th to endNight
17%18%30%23%10%
720
December1st to 15thNight
21%18%31%16%10%1
720
16th to endNight
19%19%37%20%2
768
Page generated at 2017-08-13 14:16:36. Version ac04

Copyright 2017 A. Danko


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