Ward Pound Ridge Reservation
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Ward Pound Ridge Reservation clear sky chart from 2005-11-05 to 2018-02-14.

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
29%
15586
19%
48793
8%
15555
41%
15555
21%
31252

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
19%
780
21%
2716
7%
776
37%
776
17%
1674
January16th to endNight
17%
832
21%
2842
6%
832
37%
832
18%
1757
February1st to 15thNight
13%
760
18%
2389
2%
757
31%
757
16%
1572
February16th to endNight
16%
631
25%
1893
7%
631
39%
631
18%
1203
March1st to 15thNight
18%
720
18%
2160
7%
720
33%
720
17%
1424
March16th to endNight
19%
768
24%
1994
7%
768
33%
768
22%
1320
April1st to 15thNight
20%
718
17%
1796
5%
718
27%
718
22%
1252
April16th to endNight
22%
681
18%
1761
3%
681
31%
681
24%
1205
May1st to 15thNight
24%
513
18%
1593
6%
513
35%
513
18%
1080
May16th to endNight
37%
374
15%
1497
12%
374
46%
374
17%
950
June1st to 15thNight
37%
360
14%
1440
11%
360
49%
360
17%
921
June16th to endNight
49%
360
14%
1440
13%
360
59%
360
25%
834
July1st to 15thNight
47%
340
12%
1360
15%
340
51%
340
20%
834
July16th to endNight
54%
376
15%
1418
16%
354
59%
354
22%
845
August1st to 15thNight
50%
532
18%
1603
11%
530
56%
530
29%
994
August16th to endNight
54%
764
18%
1910
9%
764
57%
764
31%
1282
September1st to 15thNight
41%
720
23%
1803
11%
720
47%
720
32%
1168
September16th to endNight
48%
717
26%
1980
18%
717
54%
717
32%
1248
October1st to 15thNight
33%
720
20%
2087
11%
720
42%
720
24%
1359
October16th to endNight
26%
768
22%
2420
9%
768
41%
768
22%
1519
November1st to 15thNight
29%
760
21%
2472
9%
760
45%
760
22%
1528
November16th to endNight
24%
780
23%
2577
10%
780
41%
780
19%
1588
December1st to 15thNight
22%
780
16%
2730
6%
780
35%
780
15%
1797
December16th to endNight
14%
832
19%
2912
4%
832
32%
832
15%
1898

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%25%5%2445%7%39%
49285
Night
16%6%24424446%42%
48963
Cloud CoverDay
16%6%245%2445%7%39%
49295
Night
16%6%24424446%42%
48969
TransparencyDay
42%5%11%21%15%2
48973
Night
41%5%11%22%15%2
48793
SeeingDay
19%14%29%21%10%3
6227
Night
20%14%31%23%8%
15587

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
15%6%25%443346%42%
1552
16th to endDay
15%7%25%32345%7%40%
1732
February1st to 15thDay
16%7%35%6%3445%7%36%
1771
16th to endDay
16%7%25%5%33447%40%
1580
March1st to 15thDay
17%6%35%5%3445%6%36%
1790
16th to endDay
18%6%35%5%23335%41%
2226
April1st to 15thDay
20%6%34423346%40%
2152
16th to endDay
17%424424447%43%
2198
May1st to 15thDay
22%6%245%245%47%34%
2368
16th to endDay
17%5%25%5%25%5%5%8%36%
2618
June1st to 15thDay
22%5%2442445%8%34%
2520
16th to endDay
14%425%5%35%5%6%9%36%
2520
July1st to 15thDay
13%5%25%5%35%5%6%8%37%
2520
16th to endDay
12%5%35%5%35%6%6%7%37%
2654
August1st to 15thDay
13%6%15%435%6%6%8%38%
2332
16th to endDay
13%5%25%425%45%8%41%
2292
September1st to 15thDay
13%415%5%34447%43%
2156
16th to endDay
13%425%5%23446%45%
1980
October1st to 15thDay
18%6%25%423346%42%
1872
16th to endDay
18%414434445%42%
1803
November1st to 15thDay
19%5%23423346%45%
1716
16th to endDay
17%5%24323346%44%
1709
December1st to 15thDay
17%7%35%5%23446%38%
1560
16th to endDay
20%7%35%424346%36%
1664
January1st to 15thNight
17%5%2441335%6%43%
2716
16th to endNight
15%8%24324446%43%
2842
February1st to 15thNight
15%7%46%5%24346%39%
2388
16th to endNight
16%6%34423345%45%
1893
March1st to 15thNight
19%6%15%424446%41%
2147
16th to endNight
15%6%34423436%44%
1994
April1st to 15thNight
19%7%25%42445%7%38%
1796
16th to endNight
18%5%35%413445%42%
1761
May1st to 15thNight
18%6%35%4335%5%6%36%
1593
16th to endNight
18%5%3442335%8%38%
1495
June1st to 15thNight
20%5%25%42435%7%39%
1440
16th to endNight
11%5%245%235%5%8%46%
1440
July1st to 15thNight
13%425%426%46%8%39%
1440
16th to endNight
10%5%25%5%25%5%7%8%39%
1514
August1st to 15thNight
12%3144345%5%8%45%
1613
16th to endNight
14%325%5%245%47%43%
1910
September1st to 15thNight
15%4145%14246%48%
1803
16th to endNight
13%5%25%223345%51%
1980
October1st to 15thNight
16%7%25%422335%46%
2087
16th to endNight
18%6%23423447%42%
2420
November1st to 15thNight
16%6%25%424345%45%
2472
16th to endNight
17%6%24423446%43%
2577
December1st to 15thNight
19%7%245%2435%6%37%
2730
16th to endNight
19%7%2442445%7%36%
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%5%245%2435%6%42%
1552
16th to endDay
14%8%26%324447%40%
1732
February1st to 15thDay
16%7%25%6%3445%6%37%
1771
16th to endDay
16%6%335%3435%6%41%
1580
March1st to 15thDay
18%7%25%5%3445%7%36%
1800
16th to endDay
18%6%34423336%41%
2226
April1st to 15thDay
20%7%243235%46%40%
2152
16th to endDay
17%5%235%24346%43%
2198
May1st to 15thDay
22%6%2442445%6%34%
2368
16th to endDay
17%6%25%5%245%6%8%36%
2618
June1st to 15thDay
22%5%3442445%8%34%
2520
16th to endDay
13%5%346%35%5%6%9%36%
2520
July1st to 15thDay
12%6%25%5%35%6%6%7%37%
2520
16th to endDay
12%5%25%5%35%6%6%8%37%
2654
August1st to 15thDay
13%5%15%5%35%6%6%8%38%
2332
16th to endDay
13%4245%35%45%8%41%
2292
September1st to 15thDay
13%5%245%2445%7%44%
2156
16th to endDay
13%5%25%5%24446%45%
1980
October1st to 15thDay
18%6%145%24346%42%
1872
16th to endDay
17%4245%23445%43%
1803
November1st to 15thDay
19%5%23323346%44%
1716
16th to endDay
17%5%14423446%45%
1709
December1st to 15thDay
17%7%25%5%24446%38%
1560
16th to endDay
20%7%35%324346%37%
1664
January1st to 15thNight
17%6%2441245%6%44%
2716
16th to endNight
15%8%34323446%43%
2842
February1st to 15thNight
15%7%35%5%24345%40%
2381
16th to endNight
16%6%25%42335%5%44%
1893
March1st to 15thNight
19%6%24424346%40%
2160
16th to endNight
16%6%34323437%44%
1994
April1st to 15thNight
18%7%2432445%6%39%
1796
16th to endNight
19%6%25%423335%43%
1761
May1st to 15thNight
19%6%35%43445%6%36%
1593
16th to endNight
18%6%3441435%8%38%
1495
June1st to 15thNight
20%5%245%23347%39%
1440
16th to endNight
11%5%333335%5%8%46%
1440
July1st to 15thNight
12%5%25%5%3446%9%38%
1440
16th to endNight
10%5%345%35%5%8%7%39%
1514
August1st to 15thNight
11%4145%345%5%7%45%
1613
16th to endNight
14%3245%245%5%7%43%
1910
September1st to 15thNight
15%414413446%48%
1803
16th to endNight
13%5%26%313445%50%
1980
October1st to 15thNight
16%7%25%422335%45%
2087
16th to endNight
19%6%2342335%6%42%
2420
November1st to 15thNight
16%6%25%423445%45%
2472
16th to endNight
17%6%24424446%43%
2577
December1st to 15thNight
19%7%24425%45%5%37%
2730
16th to endNight
19%6%35%424447%37%
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
42%5%11%23%13%4
1553
16th to endDay
42%412%24%13%2
1732
February1st to 15thDay
46%412%20%13%2
1774
16th to endDay
43%410%25%15%1
1580
March1st to 15thDay
46%5%14%21%10%2
1800
16th to endDay
44%310%20%18%3
2226
April1st to 15thDay
45%49%21%15%3
2152
16th to endDay
40%5%9%21%20%2
2198
May1st to 15thDay
48%6%9%19%14%1
2368
16th to endDay
44%8%13%18%12%1
2622
June1st to 15thDay
47%7%12%19%11%1
2520
16th to endDay
41%8%13%22%12%
2520
July1st to 15thDay
42%7%11%21%15%1
2371
16th to endDay
39%8%15%21%12%2
2487
August1st to 15thDay
40%7%15%20%15%
2318
16th to endDay
38%6%10%25%17%1
2292
September1st to 15thDay
38%6%11%21%20%1
2156
16th to endDay
38%5%7%22%23%2
1980
October1st to 15thDay
42%5%10%22%17%2
1872
16th to endDay
41%411%23%17%1
1803
November1st to 15thDay
41%412%21%17%2
1716
16th to endDay
40%311%26%15%2
1709
December1st to 15thDay
45%5%14%18%14%1
1560
16th to endDay
47%413%19%12%1
1664
January1st to 15thNight
40%412%23%14%3
2716
16th to endNight
41%411%23%15%2
2842
February1st to 15thNight
45%412%21%12%2
2389
16th to endNight
41%39%24%18%2
1893
March1st to 15thNight
43%412%21%13%3
2160
16th to endNight
40%410%22%18%4
1994
April1st to 15thNight
44%411%20%15%2
1796
16th to endNight
44%38%19%20%2
1761
May1st to 15thNight
47%410%19%15%2
1593
16th to endNight
44%6%14%19%13%1
1497
June1st to 15thNight
45%6%12%20%13%1
1440
16th to endNight
35%7%14%27%14%
1440
July1st to 15thNight
40%8%13%21%14%2
1360
16th to endNight
37%8%16%22%12%2
1418
August1st to 15thNight
35%7%13%25%15%1
1603
16th to endNight
37%7%12%22%18%1
1910
September1st to 15thNight
36%5%10%26%18%1
1803
16th to endNight
36%5%6%23%26%1
1980
October1st to 15thNight
42%410%23%16%2
2087
16th to endNight
40%413%24%15%
2420
November1st to 15thNight
40%411%21%18%3
2472
16th to endNight
41%310%27%13%2
2577
December1st to 15thNight
47%413%19%13%
2730
16th to endNight
46%412%21%13%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
18%36%30%11%21
90
16th to endDay
23%20%38%16%1
112
February1st to 15thDay
24%32%28%13%
207
16th to endDay
17%28%35%14%3
239
March1st to 15thDay
21%24%32%16%4
270
16th to endDay
21%22%32%15%33
288
April1st to 15thDay
26%17%31%14%8%1
270
16th to endDay
21%15%36%14%10%1
270
May1st to 15thDay
32%16%26%16%5%3
288
16th to endDay
19%11%29%28%9%2
331
June1st to 15thDay
21%12%27%26%11%1
315
16th to endDay
15%11%31%26%13%1
315
July1st to 15thDay
16%6%32%27%14%2
305
16th to endDay
11%7%25%30%22%2
326
August1st to 15thDay
15%5%23%31%18%6%
313
16th to endDay
12%324%31%18%10%
332
September1st to 15thDay
14%12%30%20%14%7%
315
16th to endDay
17%5%28%19%14%13%
314
October1st to 15thDay
22%7%26%23%16%3
315
16th to endDay
18%18%31%20%10%
307
November1st to 15thDay
21%13%32%20%8%2
280
16th to endDay
20%23%29%18%7%
239
December1st to 15thDay
22%32%24%11%10%
90
16th to endDay
28%29%37%5%
96
January1st to 15thNight
20%22%34%18%4
780
16th to endNight
20%22%36%18%1
832
February1st to 15thNight
21%21%37%18%1
760
16th to endNight
21%24%33%18%2
631
March1st to 15thNight
23%21%33%18%2
720
16th to endNight
20%22%33%17%5%
768
April1st to 15thNight
21%18%36%19%4
718
16th to endNight
22%16%35%19%6%
681
May1st to 15thNight
23%15%33%20%7%
513
16th to endNight
21%9%26%33%8%
375
June1st to 15thNight
20%6%28%32%12%
360
16th to endNight
12%228%44%11%
360
July1st to 15thNight
15%325%37%16%
340
16th to endNight
9%224%41%19%1
376
August1st to 15thNight
14%224%38%18%
532
16th to endNight
14%418%34%24%3
764
September1st to 15thNight
17%6%29%30%14%1
720
16th to endNight
16%5%24%28%20%4
717
October1st to 15thNight
19%10%30%23%14%1
720
16th to endNight
23%16%31%20%7%
768
November1st to 15thNight
20%13%32%23%9%1
760
16th to endNight
21%17%30%20%7%1
780
December1st to 15thNight
25%17%31%19%5%
780
16th to endNight
23%22%36%15%2
832
Page generated at 2018-02-15 10:58:49. Version ac04

Copyright 2018 A. Danko


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