Hauppauge
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hauppauge clear sky chart from 2005-11-05 to 2017-03-21.

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%
14499
19%
45242
10%
14468
46%
14468
23%
29269

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
23%
720
20%
2506
8%
716
39%
716
20%
1564
January16th to endNight
20%
768
20%
2628
7%
768
37%
768
20%
1648
February1st to 15thNight
20%
704
17%
2189
4%
701
34%
701
20%
1448
February16th to endNight
23%
631
24%
1893
9%
631
43%
631
24%
1196
March1st to 15thNight
26%
720
18%
2160
8%
720
39%
720
24%
1429
March16th to endNight
27%
728
23%
1901
8%
728
39%
728
29%
1232
April1st to 15thNight
32%
658
17%
1646
6%
658
37%
658
26%
1159
April16th to endNight
39%
619
18%
1609
6%
619
45%
619
28%
1088
May1st to 15thNight
36%
495
17%
1485
8%
495
43%
495
21%
1024
May16th to endNight
47%
347
14%
1374
14%
347
52%
347
19%
883
June1st to 15thNight
45%
330
15%
1320
16%
330
53%
330
17%
859
June16th to endNight
66%
330
13%
1320
18%
330
69%
330
24%
781
July1st to 15thNight
57%
310
12%
1240
17%
310
58%
310
20%
765
July16th to endNight
62%
348
15%
1306
16%
326
68%
326
22%
790
August1st to 15thNight
61%
502
20%
1483
16%
500
62%
500
31%
902
August16th to endNight
63%
700
17%
1750
10%
700
65%
700
32%
1174
September1st to 15thNight
54%
660
23%
1664
15%
660
57%
660
31%
1113
September16th to endNight
53%
657
23%
1815
18%
657
58%
657
31%
1166
October1st to 15thNight
39%
660
21%
1894
14%
660
46%
660
25%
1246
October16th to endNight
32%
704
18%
2225
9%
704
43%
704
23%
1429
November1st to 15thNight
32%
700
21%
2277
12%
700
46%
700
24%
1426
November16th to endNight
30%
720
19%
2349
10%
720
42%
720
21%
1509
December1st to 15thNight
26%
720
15%
2520
7%
720
38%
720
18%
1646
December16th to endNight
20%
768
19%
2688
5%
768
36%
768
17%
1792

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
15%5%2442445%7%42%
45623
Night
16%6%24424446%42%
45412
Cloud CoverDay
15%5%2442445%7%41%
45633
Night
16%6%24424446%42%
45417
TransparencyDay
40%6%13%21%15%1
45311
Night
42%5%12%21%15%2
45242
SeeingDay
18%5%25%28%18%4
5139
Night
19%7%30%29%11%1
14500

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
16%6%245%2435%6%41%
1432
16th to endDay
14%7%35%5%24347%41%
1593
February1st to 15thDay
16%5%345%24445%41%
1670
16th to endDay
14%5%25%425%35%5%44%
1580
March1st to 15thDay
16%7%25%32446%7%38%
1790
16th to endDay
15%7%34423447%43%
2092
April1st to 15thDay
18%6%34423446%40%
1972
16th to endDay
16%41332445%6%46%
2021
May1st to 15thDay
22%7%24314347%38%
2141
16th to endDay
15%5%134245%6%9%40%
2394
June1st to 15thDay
21%5%245%2345%8%35%
2310
16th to endDay
11%4244345%6%9%42%
2310
July1st to 15thDay
10%435%4345%6%10%41%
2310
16th to endDay
11%4245%345%7%8%41%
2458
August1st to 15thDay
11%41442447%9%44%
2122
16th to endDay
12%425%5%3446%8%43%
2100
September1st to 15thDay
13%41442445%7%46%
1965
16th to endDay
16%424433346%44%
1815
October1st to 15thDay
18%5%24424347%42%
1735
16th to endDay
17%424433446%44%
1645
November1st to 15thDay
19%5%25%423335%44%
1581
16th to endDay
14%6%25%435%346%43%
1611
December1st to 15thDay
17%6%25%4235%5%6%39%
1440
16th to endDay
21%8%35%32335%6%37%
1536
January1st to 15thNight
18%5%24423336%43%
2506
16th to endNight
17%7%34323347%42%
2628
February1st to 15thNight
14%8%35%424445%40%
2188
16th to endNight
17%5%24324445%45%
1893
March1st to 15thNight
18%5%24324346%42%
2147
16th to endNight
15%7%24413446%44%
1901
April1st to 15thNight
19%6%25%424446%39%
1646
16th to endNight
18%5%25%322446%42%
1609
May1st to 15thNight
18%7%34425%347%37%
1485
16th to endNight
19%5%25%42346%8%36%
1372
June1st to 15thNight
21%6%24323349%36%
1320
16th to endNight
10%436%5%25%5%5%9%43%
1320
July1st to 15thNight
10%6%35%4246%7%10%38%
1320
16th to endNight
9%425%5%35%6%6%10%38%
1402
August1st to 15thNight
8%5%235%35%6%7%8%44%
1493
16th to endNight
12%424435%5%5%7%43%
1750
September1st to 15thNight
15%41442445%6%45%
1664
16th to endNight
15%415%433336%48%
1815
October1st to 15thNight
17%6%25%5%23345%44%
1894
16th to endNight
18%5%25%42335%5%43%
2225
November1st to 15thNight
17%5%2442343446%
2277
16th to endNight
17%6%2442345%6%41%
2349
December1st to 15thNight
20%6%25%424347%38%
2520
16th to endNight
19%6%35%42445%5%38%
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
16%6%145%34346%41%
1432
16th to endDay
14%7%35%423447%41%
1593
February1st to 15thDay
16%5%346%24445%42%
1670
16th to endDay
15%5%26%425%45%5%43%
1580
March1st to 15thDay
17%6%35%42435%8%38%
1800
16th to endDay
16%7%24423446%43%
2092
April1st to 15thDay
19%6%25%323346%40%
1972
16th to endDay
16%5%24324447%45%
2021
May1st to 15thDay
22%7%24323348%37%
2141
16th to endDay
15%6%135%235%6%8%39%
2394
June1st to 15thDay
21%5%245%2435%8%35%
2310
16th to endDay
10%424435%46%9%42%
2310
July1st to 15thDay
9%5%35%425%5%7%9%41%
2310
16th to endDay
11%5%245%35%5%7%9%40%
2458
August1st to 15thDay
11%424425%47%9%44%
2122
16th to endDay
12%425%4245%6%9%42%
2100
September1st to 15thDay
13%42432445%7%46%
1965
16th to endDay
15%425%433346%44%
1815
October1st to 15thDay
18%5%25%333347%42%
1735
16th to endDay
16%42442345%6%43%
1645
November1st to 15thDay
19%5%24423335%45%
1581
16th to endDay
14%6%24424447%43%
1611
December1st to 15thDay
18%5%244335%5%6%40%
1440
16th to endDay
21%8%25%323246%38%
1536
January1st to 15thNight
19%5%24423336%43%
2506
16th to endNight
17%8%24333347%42%
2628
February1st to 15thNight
14%8%25%5%24445%41%
2181
16th to endNight
17%5%14324345%46%
1893
March1st to 15thNight
18%6%24414346%42%
2160
16th to endNight
15%7%25%312446%45%
1900
April1st to 15thNight
20%5%25%42345%6%39%
1646
16th to endNight
18%6%34413447%42%
1609
May1st to 15thNight
18%8%35%425%346%36%
1485
16th to endNight
19%6%25%5%2246%9%35%
1372
June1st to 15thNight
22%6%3342435%8%36%
1320
16th to endNight
10%426%435%46%8%43%
1320
July1st to 15thNight
11%6%335%25%6%7%9%38%
1320
16th to endNight
9%5%345%36%5%6%10%38%
1402
August1st to 15thNight
8%6%135%35%6%7%8%44%
1493
16th to endNight
12%5%24435%5%5%7%43%
1750
September1st to 15thNight
15%42332445%5%45%
1664
16th to endNight
15%425%423345%48%
1815
October1st to 15thNight
17%7%25%423435%44%
1894
16th to endNight
18%5%24423445%44%
2225
November1st to 15thNight
17%5%25%42333446%
2277
16th to endNight
18%5%2442335%6%41%
2349
December1st to 15thNight
20%6%24424446%39%
2520
16th to endNight
20%6%25%42445%5%38%
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
42%5%15%23%10%2
1433
16th to endDay
43%313%24%12%2
1593
February1st to 15thDay
43%414%21%13%1
1673
16th to endDay
40%5%11%26%14%1
1580
March1st to 15thDay
43%6%14%22%10%2
1800
16th to endDay
41%411%21%17%2
2092
April1st to 15thDay
44%410%20%16%3
1972
16th to endDay
36%5%11%21%20%3
2021
May1st to 15thDay
46%6%10%20%14%1
2141
16th to endDay
39%9%17%18%13%2
2398
June1st to 15thDay
46%7%13%20%11%1
2310
16th to endDay
35%8%15%24%13%1
2310
July1st to 15thDay
37%7%14%22%17%1
2161
16th to endDay
36%8%15%23%12%2
2291
August1st to 15thDay
34%7%16%23%16%1
2108
16th to endDay
37%6%11%23%19%2
2100
September1st to 15thDay
35%6%15%19%21%1
1965
16th to endDay
39%5%8%22%22%1
1815
October1st to 15thDay
41%5%11%22%17%1
1735
16th to endDay
39%6%12%23%16%1
1645
November1st to 15thDay
42%5%12%19%18%1
1581
16th to endDay
40%5%13%24%13%2
1611
December1st to 15thDay
43%6%18%17%13%
1440
16th to endDay
48%5%15%18%11%
1536
January1st to 15thNight
42%413%23%13%2
2506
16th to endNight
42%411%23%14%2
2628
February1st to 15thNight
44%6%12%21%12%2
2189
16th to endNight
40%410%23%18%3
1893
March1st to 15thNight
43%5%13%19%14%3
2160
16th to endNight
39%410%22%18%4
1901
April1st to 15thNight
45%5%11%18%15%2
1646
16th to endNight
42%5%9%17%21%3
1609
May1st to 15thNight
46%7%10%18%14%3
1485
16th to endNight
44%7%15%16%14%1
1374
June1st to 15thNight
47%6%12%18%13%1
1320
16th to endNight
37%7%13%26%14%1
1320
July1st to 15thNight
39%10%14%20%14%1
1240
16th to endNight
36%10%14%25%10%2
1306
August1st to 15thNight
33%8%14%26%15%2
1483
16th to endNight
36%8%12%24%16%1
1750
September1st to 15thNight
37%7%11%25%17%
1664
16th to endNight
38%5%7%21%24%1
1815
October1st to 15thNight
42%5%10%22%15%3
1894
16th to endNight
42%5%13%22%14%
2225
November1st to 15thNight
41%411%20%19%3
2277
16th to endNight
42%5%12%24%11%2
2349
December1st to 15thNight
46%5%15%19%12%
2520
16th to endNight
47%5%13%20%12%1
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
18%13%33%28%6%
60
16th to endDay
20%6%42%26%4
73
February1st to 15thDay
22%9%39%26%2
186
16th to endDay
16%11%38%23%9%
239
March1st to 15thDay
22%8%37%24%6%
270
16th to endDay
17%8%40%21%9%2
245
April1st to 15thDay
22%8%31%22%13%
210
16th to endDay
18%328%32%14%3
210
May1st to 15thDay
33%5%22%21%13%3
228
16th to endDay
17%219%30%26%2
267
June1st to 15thDay
22%321%27%21%2
255
16th to endDay
13%116%39%25%2
255
July1st to 15thDay
12%112%40%28%4
245
16th to endDay
10%213%38%27%7%
270
August1st to 15thDay
12%12%36%31%5%
253
16th to endDay
10%114%31%27%13%
268
September1st to 15thDay
18%116%27%24%10%
255
16th to endDay
20%216%26%23%10%
254
October1st to 15thDay
24%5%17%24%22%6%
255
16th to endDay
13%7%35%27%14%
251
November1st to 15thDay
20%10%24%26%15%2
235
16th to endDay
16%12%31%26%12%1
231
December1st to 15thDay
18%11%40%18%10%1
60
16th to endDay
32%9%40%15%1
64
January1st to 15thNight
21%11%40%22%4
720
16th to endNight
23%12%40%22%1
768
February1st to 15thNight
19%11%42%24%1
704
16th to endNight
20%11%39%24%3
631
March1st to 15thNight
21%8%39%24%6%
720
16th to endNight
18%8%39%23%7%
728
April1st to 15thNight
22%6%34%30%6%
658
16th to endNight
20%431%33%9%
619
May1st to 15thNight
21%331%31%11%1
495
16th to endNight
22%216%37%18%1
348
June1st to 15thNight
25%216%36%19%
330
16th to endNight
12%12%53%19%1
330
July1st to 15thNight
12%218%40%23%1
310
16th to endNight
11%115%46%22%2
348
August1st to 15thNight
10%117%45%23%
502
16th to endNight
14%210%34%33%4
700
September1st to 15thNight
19%119%37%18%4
660
16th to endNight
18%118%31%24%6%
657
October1st to 15thNight
21%5%27%26%16%1
660
16th to endNight
21%9%32%27%8%
704
November1st to 15thNight
19%9%32%22%13%2
700
16th to endNight
19%11%32%24%10%
720
December1st to 15thNight
23%12%33%22%6%
720
16th to endNight
23%12%41%20%2
768
Page generated at 2017-03-22 02:42:24. Version ac04

Copyright 2017 A. Danko


Hauppauge Clear Sky Chart | Charts Home