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 2018-02-22.

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%
15660
19%
48883
10%
15629
46%
15629
23%
31650

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%
780
21%
2716
8%
776
39%
776
20%
1673
January16th to endNight
20%
832
20%
2847
7%
832
37%
832
20%
1779
February1st to 15thNight
19%
764
17%
2375
4%
761
34%
761
20%
1585
February16th to endNight
23%
659
24%
1976
9%
659
42%
659
24%
1260
March1st to 15thNight
27%
720
18%
2160
8%
720
39%
720
24%
1429
March16th to endNight
27%
768
23%
2001
8%
768
39%
768
28%
1310
April1st to 15thNight
34%
718
16%
1796
6%
718
38%
718
26%
1255
April16th to endNight
38%
675
18%
1755
6%
675
44%
675
27%
1208
May1st to 15thNight
35%
540
16%
1620
8%
540
41%
540
20%
1135
May16th to endNight
46%
379
14%
1502
15%
379
51%
379
18%
976
June1st to 15thNight
47%
360
14%
1440
16%
360
54%
360
18%
924
June16th to endNight
63%
360
14%
1440
18%
360
67%
360
24%
854
July1st to 15thNight
59%
340
11%
1360
16%
340
60%
340
20%
840
July16th to endNight
61%
376
16%
1418
17%
354
67%
354
21%
860
August1st to 15thNight
61%
548
19%
1619
15%
546
63%
546
31%
988
August16th to endNight
64%
764
18%
1910
10%
764
66%
764
32%
1280
September1st to 15thNight
54%
720
22%
1815
14%
720
57%
720
32%
1213
September16th to endNight
52%
717
23%
1980
18%
717
57%
717
30%
1286
October1st to 15thNight
40%
720
20%
2066
13%
720
47%
720
25%
1356
October16th to endNight
32%
768
21%
2428
11%
768
44%
768
24%
1543
November1st to 15thNight
34%
760
20%
2472
11%
760
47%
760
23%
1561
November16th to endNight
30%
780
21%
2545
11%
780
43%
780
22%
1605
December1st to 15thNight
26%
780
15%
2730
6%
780
37%
780
17%
1803
December16th to endNight
20%
832
19%
2912
5%
832
36%
832
18%
1927

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
16%5%2442445%7%41%
49376
Night
16%6%24424446%42%
49053
Cloud CoverDay
16%5%2442445%7%41%
49386
Night
16%6%24424446%42%
49058
TransparencyDay
40%6%13%21%15%1
49064
Night
42%5%12%21%15%2
48883
SeeingDay
19%5%24%29%17%3
6317
Night
20%6%30%29%11%1
15661

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%23346%43%
1552
16th to endDay
15%7%345%24347%41%
1726
February1st to 15thDay
17%5%35%5%24445%41%
1814
16th to endDay
15%6%25%42435%5%44%
1644
March1st to 15thDay
16%7%25%32446%7%38%
1790
16th to endDay
17%7%24423446%42%
2222
April1st to 15thDay
18%6%34424446%40%
2152
16th to endDay
17%5%13324446%45%
2205
May1st to 15thDay
21%7%24314347%37%
2337
16th to endDay
16%5%134245%6%9%39%
2618
June1st to 15thDay
20%5%2442345%8%37%
2520
16th to endDay
11%4244345%6%9%42%
2520
July1st to 15thDay
10%425%5%345%6%9%41%
2520
16th to endDay
12%4244345%7%8%40%
2654
August1st to 15thDay
12%5%145%2447%9%42%
2315
16th to endDay
12%425%42346%8%44%
2292
September1st to 15thDay
13%41442445%7%46%
2143
16th to endDay
16%424433446%44%
1980
October1st to 15thDay
18%6%24324347%42%
1893
16th to endDay
17%424433446%44%
1794
November1st to 15thDay
19%5%25%422436%43%
1716
16th to endDay
13%5%25%324346%45%
1745
December1st to 15thDay
17%6%25%4235%5%6%39%
1560
16th to endDay
21%8%35%323346%37%
1664
January1st to 15thNight
18%5%24423346%44%
2716
16th to endNight
17%7%24323347%42%
2847
February1st to 15thNight
15%8%35%424445%39%
2374
16th to endNight
18%5%24324346%44%
1976
March1st to 15thNight
18%5%24324346%42%
2147
16th to endNight
16%7%24413446%44%
2001
April1st to 15thNight
18%6%25%424447%39%
1796
16th to endNight
19%6%25%323446%41%
1755
May1st to 15thNight
18%7%35%5%25%346%35%
1620
16th to endNight
20%6%25%42346%8%36%
1500
June1st to 15thNight
21%6%24324348%38%
1440
16th to endNight
10%425%5%25%5%5%9%43%
1440
July1st to 15thNight
11%6%25%4246%7%10%37%
1440
16th to endNight
10%5%25%5%35%6%7%10%38%
1514
August1st to 15thNight
8%5%235%346%7%8%44%
1629
16th to endNight
12%4244346%5%7%43%
1910
September1st to 15thNight
15%414325%45%5%46%
1815
16th to endNight
15%425%433346%47%
1980
October1st to 15thNight
16%7%25%5%23345%44%
2066
16th to endNight
18%5%2442335%5%44%
2428
November1st to 15thNight
17%5%24423445%45%
2472
16th to endNight
16%5%2442335%6%43%
2545
December1st to 15thNight
20%6%25%434347%37%
2730
16th to endNight
19%7%25%42445%5%39%
2912

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%14434346%43%
1552
16th to endDay
15%7%35%423347%41%
1726
February1st to 15thDay
16%6%35%6%34445%41%
1814
16th to endDay
15%5%26%424445%43%
1644
March1st to 15thDay
17%6%35%42435%8%38%
1800
16th to endDay
17%7%24423446%42%
2222
April1st to 15thDay
18%6%25%324446%40%
2152
16th to endDay
17%6%24314447%44%
2205
May1st to 15thDay
21%7%24423348%37%
2337
16th to endDay
17%6%135%235%6%8%38%
2618
June1st to 15thDay
20%5%245%2435%8%37%
2520
16th to endDay
11%424435%46%9%42%
2520
July1st to 15thDay
10%5%35%5%25%5%7%9%40%
2520
16th to endDay
11%5%245%35%5%7%9%40%
2654
August1st to 15thDay
11%424425%46%9%42%
2315
16th to endDay
12%415%42446%9%43%
2292
September1st to 15thDay
12%5%2432445%7%47%
2143
16th to endDay
16%5%25%433346%44%
1980
October1st to 15thDay
18%5%25%333447%42%
1893
16th to endDay
16%42442345%6%44%
1794
November1st to 15thDay
19%5%24423436%43%
1716
16th to endDay
13%6%24424447%45%
1745
December1st to 15thDay
18%6%244335%5%6%39%
1560
16th to endDay
20%8%35%323346%37%
1664
January1st to 15thNight
18%424423436%44%
2716
16th to endNight
17%8%24333346%43%
2847
February1st to 15thNight
15%8%25%5%24445%40%
2367
16th to endNight
18%5%24324345%44%
1976
March1st to 15thNight
18%6%24414346%42%
2160
16th to endNight
15%7%25%312446%44%
2000
April1st to 15thNight
19%5%26%42345%6%39%
1796
16th to endNight
19%7%34413346%40%
1755
May1st to 15thNight
18%7%35%5%36%346%35%
1620
16th to endNight
21%6%25%5%2246%9%34%
1500
June1st to 15thNight
21%5%2342335%8%37%
1440
16th to endNight
10%426%435%5%6%8%43%
1440
July1st to 15thNight
12%6%235%25%6%7%9%37%
1440
16th to endNight
9%5%35%6%35%5%6%10%37%
1514
August1st to 15thNight
8%6%135%346%7%8%44%
1629
16th to endNight
12%5%24435%5%5%7%43%
1910
September1st to 15thNight
15%414425%45%5%45%
1815
16th to endNight
15%425%423345%47%
1980
October1st to 15thNight
17%7%25%42343444%
2066
16th to endNight
18%5%24423445%45%
2428
November1st to 15thNight
16%5%25%423445%45%
2472
16th to endNight
17%5%2442335%6%43%
2545
December1st to 15thNight
20%6%25%5%24446%37%
2730
16th to endNight
19%6%25%42345%5%39%
2912

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
41%5%14%24%11%3
1553
16th to endDay
43%313%24%13%2
1726
February1st to 15thDay
44%413%21%13%1
1817
16th to endDay
40%5%11%26%14%1
1644
March1st to 15thDay
43%6%14%22%10%2
1800
16th to endDay
42%411%21%17%3
2222
April1st to 15thDay
43%410%21%15%3
2152
16th to endDay
38%5%11%21%19%3
2205
May1st to 15thDay
45%6%10%20%14%1
2337
16th to endDay
40%8%16%18%12%1
2622
June1st to 15thDay
44%7%13%21%12%1
2520
16th to endDay
36%8%15%24%14%1
2520
July1st to 15thDay
37%7%14%21%17%1
2371
16th to endDay
36%8%15%23%12%2
2487
August1st to 15thDay
35%7%16%22%16%1
2301
16th to endDay
36%6%11%23%20%1
2292
September1st to 15thDay
35%6%14%20%21%1
2143
16th to endDay
40%5%7%22%22%2
1980
October1st to 15thDay
41%5%11%21%18%1
1893
16th to endDay
39%6%11%24%17%1
1794
November1st to 15thDay
42%5%12%19%17%1
1716
16th to endDay
39%5%12%25%14%2
1745
December1st to 15thDay
43%5%17%16%14%
1560
16th to endDay
48%5%15%18%12%
1664
January1st to 15thNight
41%5%12%23%14%3
2716
16th to endNight
42%411%23%14%2
2847
February1st to 15thNight
45%6%13%21%12%2
2375
16th to endNight
41%410%23%17%2
1976
March1st to 15thNight
43%5%13%19%14%3
2160
16th to endNight
39%410%21%17%4
2001
April1st to 15thNight
44%6%11%19%15%2
1796
16th to endNight
44%5%9%17%20%3
1755
May1st to 15thNight
48%6%9%17%14%2
1620
16th to endNight
45%7%15%17%13%1
1502
June1st to 15thNight
46%5%12%18%15%1
1440
16th to endNight
37%7%13%25%14%1
1440
July1st to 15thNight
38%10%14%20%13%1
1360
16th to endNight
37%10%13%25%11%2
1418
August1st to 15thNight
33%8%14%26%15%1
1619
16th to endNight
36%8%12%23%17%1
1910
September1st to 15thNight
37%7%10%25%17%1
1815
16th to endNight
39%5%7%20%24%2
1980
October1st to 15thNight
42%5%10%22%16%2
2066
16th to endNight
41%413%23%15%
2428
November1st to 15thNight
41%411%20%18%2
2472
16th to endNight
41%5%12%25%12%2
2545
December1st to 15thNight
47%5%15%18%12%
2730
16th to endNight
46%5%13%20%12%1
2912

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
16%14%40%21%7%
90
16th to endDay
23%438%27%6%
110
February1st to 15thDay
23%9%41%23%2
240
16th to endDay
17%10%38%24%8%
265
March1st to 15thDay
22%8%37%24%6%
270
16th to endDay
20%9%38%21%8%1
288
April1st to 15thDay
22%6%30%25%14%
270
16th to endDay
24%324%32%11%2
270
May1st to 15thDay
31%425%25%11%2
288
16th to endDay
20%217%32%24%2
331
June1st to 15thDay
21%319%27%23%4
315
16th to endDay
14%120%39%21%2
315
July1st to 15thDay
14%11%42%25%3
305
16th to endDay
12%211%37%29%7%
326
August1st to 15thDay
15%12%35%29%7%
313
16th to endDay
10%113%36%26%10%
332
September1st to 15thDay
17%120%27%23%9%
315
16th to endDay
20%215%26%22%12%
314
October1st to 15thDay
24%416%25%21%7%
315
16th to endDay
14%8%31%26%17%1
304
November1st to 15thDay
21%10%23%28%14%1
280
16th to endDay
15%12%32%25%12%1
275
December1st to 15thDay
22%10%36%18%11%1
90
16th to endDay
30%14%42%11%1
96
January1st to 15thNight
20%10%41%22%4
780
16th to endNight
23%11%40%23%1
832
February1st to 15thNight
20%10%43%23%1
764
16th to endNight
21%11%39%24%3
659
March1st to 15thNight
21%8%39%24%6%
720
16th to endNight
19%8%39%24%7%
768
April1st to 15thNight
22%5%33%31%6%
718
16th to endNight
21%430%33%8%
675
May1st to 15thNight
21%431%30%10%1
540
16th to endNight
23%216%37%18%1
380
June1st to 15thNight
24%215%37%20%
360
16th to endNight
12%15%51%18%1
360
July1st to 15thNight
13%216%42%23%1
340
16th to endNight
12%114%46%22%2
376
August1st to 15thNight
11%116%43%25%1
548
16th to endNight
15%210%35%32%4
764
September1st to 15thNight
18%120%37%17%4
720
16th to endNight
18%117%31%24%6%
717
October1st to 15thNight
21%5%26%26%16%2
720
16th to endNight
21%8%32%26%9%
768
November1st to 15thNight
19%8%32%24%13%1
760
16th to endNight
18%10%33%25%10%
780
December1st to 15thNight
23%11%33%22%7%
780
16th to endNight
23%11%41%20%2
832
Page generated at 2018-02-23 11:21:36. Version ac04

Copyright 2018 A. Danko


Hauppauge Clear Sky Chart |Charts Home