Hamlin Beach State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Hamlin Beach State Park 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
30%
15427
12%
48841
8%
15394
34%
15394
15%
35897

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
9%
778
5%
2716
2%
776
13%
776
4%
2322
January16th to endNight
11%
832
6%
2720
2%
832
16%
832
4%
2302
February1st to 15thNight
7%
759
5%
2468
1%
757
12%
757
5%
2065
February16th to endNight
16%
631
7%
1991
3%
631
20%
631
8%
1612
March1st to 15thNight
19%
720
10%
2007
5%
720
25%
720
12%
1612
March16th to endNight
27%
768
15%
2095
8%
768
34%
768
19%
1531
April1st to 15thNight
24%
718
13%
1796
4%
718
29%
718
18%
1370
April16th to endNight
39%
630
17%
1710
8%
630
44%
630
26%
1144
May1st to 15thNight
44%
440
16%
1520
12%
440
50%
440
19%
1012
May16th to endNight
45%
374
16%
1497
15%
374
55%
374
25%
866
June1st to 15thNight
46%
360
13%
1440
13%
360
55%
360
19%
911
June16th to endNight
50%
360
11%
1440
16%
360
54%
360
21%
872
July1st to 15thNight
56%
340
16%
1360
23%
340
59%
340
29%
730
July16th to endNight
61%
429
16%
1467
16%
403
65%
403
31%
815
August1st to 15thNight
59%
539
16%
1609
12%
536
62%
536
32%
968
August16th to endNight
59%
672
22%
1818
13%
672
62%
672
35%
1112
September1st to 15thNight
51%
720
20%
1800
11%
720
54%
720
31%
1206
September16th to endNight
54%
717
22%
1989
16%
717
57%
717
30%
1280
October1st to 15thNight
37%
720
12%
2160
11%
720
40%
720
18%
1564
October16th to endNight
19%
768
8%
2304
4%
768
25%
768
12%
1805
November1st to 15thNight
27%
760
14%
2562
13%
760
32%
760
14%
1826
November16th to endNight
19%
780
10%
2730
7%
780
24%
780
10%
2108
December1st to 15thNight
10%
780
4%
2730
1%
780
13%
780
5%
2301
December16th to endNight
7%
832
3%
2912
0%
832
11%
832
3%
2563

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
14%9%47%6%3445%7%31%
49234
Night
16%10%48%6%3445%6%29%
49016
Cloud CoverDay
15%9%47%6%3445%7%31%
49244
Night
16%10%47%6%3445%6%29%
49021
TransparencyDay
51%7%12%18%9%
48927
Night
54%6%12%16%8%
48841
SeeingDay
19%11%27%24%12%3
5866
Night
21%14%27%23%11%1
15431

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%15%8%13%10%46%5%35%12%
1552
16th to endDay
11%16%8%15%10%5%5%5%35%12%
1853
February1st to 15thDay
15%15%8%12%9%45%5%3314%
1695
16th to endDay
16%14%5%12%10%45%45%414%
1481
March1st to 15thDay
16%12%6%12%8%45%335%20%
1939
16th to endDay
16%10%47%434446%34%
2128
April1st to 15thDay
18%9%46%424446%33%
2152
16th to endDay
17%7%25%5%34435%40%
2259
May1st to 15thDay
13%7%26%6%345%5%7%37%
2430
16th to endDay
12%435%5%245%5%7%41%
2618
June1st to 15thDay
16%5%25%43445%8%38%
2520
16th to endDay
11%4245%345%6%9%41%
2520
July1st to 15thDay
8%4245%35%47%8%45%
2520
16th to endDay
10%5%15%6%35%5%7%11%37%
2598
August1st to 15thDay
9%5%25%5%35%5%7%9%40%
2340
16th to endDay
12%425%435%5%6%8%42%
2371
September1st to 15thDay
16%5%25%5%2445%8%39%
2160
16th to endDay
15%5%25%43435%8%41%
1969
October1st to 15thDay
20%8%36%5%3445%6%31%
1800
16th to endDay
23%11%37%7%34445%23%
1920
November1st to 15thDay
13%12%47%7%3445%6%28%
1625
16th to endDay
19%15%5%8%6%3445%6%19%
1560
December1st to 15thDay
18%18%8%12%6%2335%415%
1560
16th to endDay
19%19%8%12%7%443439%
1664
January1st to 15thNight
18%16%6%11%10%45%34413%
2716
16th to endNight
13%15%8%12%11%45%44414%
2720
February1st to 15thNight
14%17%6%12%8%35%445%15%
2466
16th to endNight
13%12%7%13%9%5%5%35%5%18%
1991
March1st to 15thNight
18%11%5%10%7%3444423%
1995
16th to endNight
16%9%5%7%5%24445%34%
2095
April1st to 15thNight
20%9%36%6%245%36%30%
1796
16th to endNight
15%6%144246%5%7%39%
1710
May1st to 15thNight
16%6%35%435%46%8%36%
1520
16th to endNight
10%426%5%2446%7%46%
1495
June1st to 15thNight
13%5%25%5%45%6%6%8%36%
1440
16th to endNight
11%5%26%5%445%5%8%40%
1440
July1st to 15thNight
6%4244245%5%8%49%
1440
16th to endNight
9%313325%5%7%9%47%
1567
August1st to 15thNight
8%3245%25%5%5%10%46%
1620
16th to endNight
8%315%5%345%6%8%47%
1818
September1st to 15thNight
15%5%245%2335%7%43%
1800
16th to endNight
15%4234245%6%8%42%
1989
October1st to 15thNight
19%7%36%5%3445%5%32%
2160
16th to endNight
27%10%36%5%245%45%23%
2304
November1st to 15thNight
16%9%46%6%35%447%29%
2562
16th to endNight
18%13%6%8%6%35%45%6%22%
2730
December1st to 15thNight
20%16%8%10%6%3445%5%13%
2730
16th to endNight
20%18%8%12%8%3444410%
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
15%15%8%11%10%5%5%5%3412%
1552
16th to endDay
12%16%8%16%9%45%5%35%12%
1853
February1st to 15thDay
15%16%7%13%9%35%43414%
1695
16th to endDay
17%14%5%12%10%25%5%4415%
1481
March1st to 15thDay
16%13%6%11%7%45%345%20%
1950
16th to endDay
15%11%47%5%34446%34%
2127
April1st to 15thDay
18%9%37%5%24336%33%
2152
16th to endDay
18%7%35%5%24445%40%
2259
May1st to 15thDay
14%6%26%6%3447%6%36%
2430
16th to endDay
12%425%5%3445%8%41%
2618
June1st to 15thDay
16%5%25%435%45%8%38%
2520
16th to endDay
12%3245%35%5%6%9%41%
2520
July1st to 15thDay
8%3245%35%5%6%9%45%
2520
16th to endDay
10%425%6%35%6%6%11%37%
2598
August1st to 15thDay
9%5%25%6%35%5%6%9%40%
2340
16th to endDay
13%425%5%245%5%7%43%
2371
September1st to 15thDay
16%5%245%2445%7%40%
2160
16th to endDay
15%425%43445%8%40%
1969
October1st to 15thDay
21%7%36%5%2446%6%32%
1800
16th to endDay
23%10%37%7%35%445%23%
1920
November1st to 15thDay
14%12%48%6%35%45%6%29%
1625
16th to endDay
19%15%48%7%445%46%20%
1560
December1st to 15thDay
18%18%7%12%6%24346%15%
1560
16th to endDay
19%20%7%13%7%35%43310%
1664
January1st to 15thNight
18%16%7%11%11%3444414%
2716
16th to endNight
13%15%7%12%10%5%5%44415%
2720
February1st to 15thNight
15%16%7%12%7%45%5%45%16%
2459
16th to endNight
13%12%7%13%9%36%445%18%
1991
March1st to 15thNight
19%11%410%8%3434424%
2007
16th to endNight
16%9%5%6%5%34445%34%
2095
April1st to 15thNight
20%10%36%6%34446%31%
1796
16th to endNight
15%6%15%4245%5%7%40%
1710
May1st to 15thNight
16%7%25%435%46%7%36%
1520
16th to endNight
11%335%4245%5%7%46%
1495
June1st to 15thNight
14%435%5%35%6%6%8%36%
1440
16th to endNight
11%435%5%35%5%5%8%40%
1440
July1st to 15thNight
6%5%245%235%5%8%49%
1440
16th to endNight
8%323335%5%7%9%47%
1567
August1st to 15thNight
8%4145%245%6%9%46%
1620
16th to endNight
8%3145%25%47%8%48%
1818
September1st to 15thNight
15%5%25%42335%7%43%
1800
16th to endNight
15%4243245%6%7%43%
1989
October1st to 15thNight
19%6%36%6%345%45%33%
2160
16th to endNight
28%10%36%5%2345%5%24%
2304
November1st to 15thNight
17%9%46%5%35%45%6%30%
2562
16th to endNight
19%12%5%7%6%25%45%6%22%
2730
December1st to 15thNight
19%16%7%10%6%25%445%15%
2730
16th to endNight
20%18%7%11%7%4444411%
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
74%6%9%7%1
1553
16th to endDay
73%7%11%6%
1853
February1st to 15thDay
72%6%8%10%
1697
16th to endDay
70%6%9%9%3
1481
March1st to 15thDay
67%5%9%12%4
1950
16th to endDay
51%5%9%20%10%1
2128
April1st to 15thDay
52%5%12%18%11%1
2152
16th to endDay
46%5%8%19%17%2
2259
May1st to 15thDay
45%7%12%22%11%
2430
16th to endDay
40%7%13%21%13%2
2622
June1st to 15thDay
44%6%12%22%13%
2520
16th to endDay
37%8%15%23%14%
2520
July1st to 15thDay
33%8%13%26%17%
2371
16th to endDay
40%10%15%22%11%
2435
August1st to 15thDay
39%8%18%19%13%
2327
16th to endDay
38%8%15%25%11%1
2371
September1st to 15thDay
42%6%13%23%11%
2160
16th to endDay
41%5%14%23%13%
1969
October1st to 15thDay
52%6%10%18%11%
1800
16th to endDay
62%5%15%12%2
1920
November1st to 15thDay
54%7%14%13%8%
1625
16th to endDay
63%7%12%12%3
1560
December1st to 15thDay
70%5%13%8%1
1560
16th to endDay
76%7%8%6%1
1664
January1st to 15thNight
73%6%9%8%2
2716
16th to endNight
72%6%10%9%2
2720
February1st to 15thNight
69%6%9%11%1
2468
16th to endNight
66%5%12%12%3
1991
March1st to 15thNight
62%5%11%14%5%
2007
16th to endNight
51%6%10%17%12%1
2095
April1st to 15thNight
55%5%9%18%10%1
1796
16th to endNight
41%6%12%20%14%3
1710
May1st to 15thNight
45%7%11%19%14%1
1520
16th to endNight
35%7%15%22%17%2
1497
June1st to 15thNight
41%8%13%22%13%
1440
16th to endNight
40%6%13%20%17%1
1440
July1st to 15thNight
31%6%14%24%20%1
1360
16th to endNight
30%7%16%27%14%2
1467
August1st to 15thNight
32%8%18%27%12%
1609
16th to endNight
31%7%13%31%14%1
1818
September1st to 15thNight
38%6%12%27%13%1
1800
16th to endNight
37%6%13%26%15%
1989
October1st to 15thNight
50%7%11%17%12%
2160
16th to endNight
60%6%14%11%5%
2304
November1st to 15thNight
53%6%13%16%9%1
2562
16th to endNight
61%6%14%13%3
2730
December1st to 15thNight
70%7%12%8%1
2730
16th to endNight
75%7%9%6%
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
15%35%27%15%5%
90
16th to endDay
30%22%36%8%1
140
February1st to 15thDay
23%36%32%7%
130
16th to endDay
26%17%40%15%
140
March1st to 15thDay
24%20%31%19%4
270
16th to endDay
25%12%35%20%42
288
April1st to 15thDay
27%13%32%19%5%
270
16th to endDay
20%12%28%24%10%3
270
May1st to 15thDay
21%10%29%23%11%4
288
16th to endDay
14%6%36%26%12%3
331
June1st to 15thDay
22%7%25%32%10%1
315
16th to endDay
14%5%30%34%13%
315
July1st to 15thDay
9%420%39%21%4
305
16th to endDay
12%425%35%17%3
326
August1st to 15thDay
12%123%35%19%8%
313
16th to endDay
12%5%20%26%25%9%
332
September1st to 15thDay
15%320%27%23%8%
315
16th to endDay
16%7%19%20%20%14%
314
October1st to 15thDay
23%8%26%19%15%6%
315
16th to endDay
28%16%30%17%7%
336
November1st to 15thDay
18%13%35%21%8%3
187
16th to endDay
25%23%26%20%4
90
December1st to 15thDay
17%35%18%23%4
90
16th to endDay
35%31%26%7%
96
January1st to 15thNight
25%28%29%13%2
780
16th to endNight
20%27%32%16%3
832
February1st to 15thNight
24%27%33%12%1
760
16th to endNight
20%25%30%21%2
631
March1st to 15thNight
25%20%29%21%3
720
16th to endNight
19%13%34%22%9%
768
April1st to 15thNight
24%14%31%24%4
718
16th to endNight
19%9%29%29%10%1
630
May1st to 15thNight
21%423%31%18%
440
16th to endNight
12%331%34%17%1
375
June1st to 15thNight
14%426%38%15%1
360
16th to endNight
12%325%42%15%
360
July1st to 15thNight
7%322%38%26%1
340
16th to endNight
10%123%38%23%3
429
August1st to 15thNight
10%221%39%22%3
539
16th to endNight
9%320%33%29%3
672
September1st to 15thNight
18%5%19%27%26%3
720
16th to endNight
16%6%17%25%24%8%
717
October1st to 15thNight
24%9%24%25%14%2
720
16th to endNight
33%13%27%20%5%
768
November1st to 15thNight
22%13%29%22%8%1
760
16th to endNight
25%22%26%15%8%
780
December1st to 15thNight
30%22%30%13%3
780
16th to endNight
29%26%29%12%1
832
Page generated at 2018-02-15 10:58:52. Version ac04

Copyright 2018 A. Danko


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