Walnut Point State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Walnut Point State Park clear sky chart from 2005-11-06 to 2024-01-17.

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
39%
24448
19%
74702
13%
24387
46%
24387
24%
49447

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 10thNight
21%
950
16%
2648
6%
946
30%
946
18%
1935
January11th to 20thNight
18%
935
14%
2617
5%
935
26%
935
15%
1991
January21st to endNight
21%
990
15%
2651
5%
990
29%
990
18%
1971
February1st to 10thNight
20%
788
12%
2228
4%
788
26%
788
16%
1661
February11th to 20thNight
23%
703
17%
2099
7%
700
31%
700
19%
1448
February21st to endNight
20%
592
18%
1776
5%
592
30%
592
17%
1253
March1st to 10thNight
26%
720
16%
2160
8%
720
32%
720
18%
1498
March11th to 20thNight
27%
707
16%
2121
8%
707
35%
707
22%
1424
March21st to endNight
28%
594
15%
1980
9%
594
37%
594
17%
1401
April1st to 10thNight
31%
540
20%
1800
12%
540
43%
540
22%
1150
April11th to 20thNight
33%
533
21%
1775
16%
533
43%
533
24%
1118
April21st to endNight
29%
540
16%
1750
7%
540
39%
540
18%
1209
May1st to 10thNight
37%
540
15%
1620
9%
540
43%
540
23%
1106
May11th to 20thNight
43%
531
16%
1580
12%
531
47%
531
25%
1057
May21st to endNight
53%
584
18%
1551
11%
582
58%
582
30%
1034
June1st to 10thNight
59%
540
20%
1440
14%
540
63%
540
37%
893
June11th to 20thNight
59%
540
24%
1440
18%
540
64%
540
40%
876
June21st to endNight
57%
540
21%
1440
15%
540
62%
540
37%
882
July1st to 10thNight
68%
525
18%
1400
16%
525
69%
525
38%
869
July11th to 20thNight
72%
522
24%
1392
19%
522
74%
522
48%
762
July21st to endNight
69%
591
28%
1487
22%
558
72%
558
46%
856
August1st to 10thNight
72%
537
24%
1608
22%
534
74%
534
37%
924
August11th to 20thNight
68%
534
21%
1776
23%
534
71%
534
31%
1029
August21st to endNight
71%
594
26%
1980
28%
594
75%
594
39%
1046
September1st to 10thNight
63%
540
25%
1800
24%
540
68%
540
33%
1010
September11th to 20thNight
66%
648
33%
1908
29%
648
70%
648
41%
1053
September21st to endNight
57%
720
28%
1980
20%
720
62%
720
37%
1186
October1st to 10thNight
55%
720
28%
1992
20%
720
60%
720
39%
1168
October11th to 20thNight
38%
720
28%
2160
16%
720
50%
720
30%
1294
October21st to endNight
30%
792
20%
2551
12%
792
41%
792
21%
1684
November1st to 10thNight
35%
740
26%
2406
16%
740
49%
740
30%
1378
November11th to 20thNight
33%
760
24%
2470
15%
760
46%
760
25%
1515
November21st to endNight
29%
760
20%
2470
13%
760
38%
760
20%
1661
December1st to 10thNight
23%
888
14%
2598
6%
888
30%
888
19%
1873
December11th to 20thNight
27%
950
17%
3193
8%
948
35%
948
17%
2236
December21st to endNight
17%
1040
7%
4855
4%
1026
24%
1026
7%
3996

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%8%46%5%345%5%7%39%
74843
Night
15%8%36%5%3445%7%41%
75000
TransparencyDay
44%6%12%22%13%2
74544
Night
44%5%11%23%15%3
74820
SeeingDay
15%9%26%25%18%7%
14493
Night
17%9%29%30%14%1
24453

By Month

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 10thDay
15%12%6%10%7%445%46%27%
1517
11th to 20thDay
18%13%7%9%7%35%445%24%
1488
21st to endDay
13%14%8%9%6%35%445%27%
1701
February1st to 10thDay
17%11%6%10%7%44445%28%
1730
11th to 20thDay
16%9%49%8%45%45%6%29%
1748
21st to endDay
17%14%5%8%5%34346%32%
1480
March1st to 10thDay
18%9%47%435%445%36%
1800
11th to 20thDay
18%10%47%5%3445%6%34%
1852
21st to endDay
21%12%5%7%6%3445%6%27%
2376
April1st to 10thDay
15%8%45%6%345%6%8%36%
2160
11th to 20thDay
16%9%35%5%24445%40%
2134
21st to endDay
21%8%26%6%25%446%35%
2209
May1st to 10thDay
17%8%46%6%346%5%8%33%
2340
11th to 20thDay
19%6%36%6%345%5%7%37%
2309
21st to endDay
10%5%36%7%46%6%7%9%38%
2725
June1st to 10thDay
9%5%25%6%35%6%6%9%45%
2520
11th to 20thDay
8%4245%46%5%6%9%48%
2520
21st to endDay
9%5%25%6%45%5%7%9%43%
2520
July1st to 10thDay
10%4345%35%6%9%11%41%
2520
11th to 20thDay
6%425%5%35%7%8%11%44%
2520
21st to endDay
8%4245%345%7%10%47%
2743
August1st to 10thDay
8%424425%5%7%11%47%
2317
11th to 20thDay
9%5%245%46%5%7%10%43%
2125
21st to endDay
7%3345%345%6%9%52%
2376
September1st to 10thDay
13%5%35%5%445%5%7%45%
2160
11th to 20thDay
10%4245%45%5%6%7%48%
2034
21st to endDay
10%4245%4446%7%51%
1980
October1st to 10thDay
12%5%145%33447%50%
1965
11th to 20thDay
16%7%35%5%2445%5%44%
1800
21st to endDay
19%9%45%433346%39%
1804
November1st to 10thDay
11%6%34423347%53%
1672
11th to 20thDay
17%8%445%3445%5%41%
1710
21st to endDay
16%9%46%5%3445%5%39%
1710
December1st to 10thDay
18%10%5%8%6%43446%30%
1577
11th to 20thDay
14%13%6%10%5%3435%7%29%
1918
21st to endDay
23%17%7%12%6%34335%16%
2783
January1st to 10thNight
14%11%5%8%6%35%5%46%32%
2648
11th to 20thNight
16%13%6%10%7%3434430%
2617
21st to endNight
16%11%6%9%5%3445%6%31%
2651
February1st to 10thNight
19%12%5%8%5%35%445%29%
2228
11th to 20thNight
16%9%48%6%34446%35%
2098
21st to endNight
21%10%36%5%34445%35%
1776
March1st to 10thNight
17%10%47%6%34435%38%
2160
11th to 20thNight
17%8%45%5%2445%7%38%
2121
21st to endNight
21%8%47%5%3445%7%32%
1980
April1st to 10thNight
13%7%35%6%345%47%43%
1800
11th to 20thNight
18%7%35%4245%46%43%
1775
21st to endNight
19%8%35%5%446%5%437%
1750
May1st to 10thNight
16%7%35%5%45%5%5%9%37%
1620
11th to 20thNight
16%6%35%5%4445%7%41%
1579
21st to endNight
9%6%36%5%47%5%5%9%41%
1551
June1st to 10thNight
9%5%26%4345%5%7%50%
1440
11th to 20thNight
8%424435%46%8%53%
1440
21st to endNight
8%4246%3446%12%46%
1440
July1st to 10thNight
9%325%5%26%5%5%9%49%
1440
11th to 20thNight
6%42332346%10%57%
1440
21st to endNight
6%335%42346%8%55%
1575
August1st to 10thNight
7%4343345%7%10%50%
1617
11th to 20thNight
6%426%5%45%5%6%7%49%
1776
21st to endNight
7%32342445%9%57%
1980
September1st to 10thNight
13%424424447%52%
1800
11th to 20thNight
7%5%2443336%8%55%
1908
21st to endNight
10%5%234235%5%7%53%
1980
October1st to 10thNight
10%4245%3345%6%56%
1992
11th to 20thNight
16%5%24433446%50%
2160
21st to endNight
19%8%245%345%5%6%40%
2551
November1st to 10thNight
10%6%24433446%53%
2406
11th to 20thNight
14%7%35%5%3445%7%45%
2470
21st to endNight
18%9%46%5%34346%38%
2470
December1st to 10thNight
17%10%5%8%6%3445%6%33%
2598
11th to 20thNight
17%10%5%7%5%34445%36%
3279
21st to endNight
26%17%6%9%6%3443419%
4884

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 10thDay
59%5%8%18%10%1
1518
11th to 20thDay
63%5%9%16%7%1
1488
21st to endDay
59%5%11%17%6%1
1701
February1st to 10thDay
58%411%17%9%1
1730
11th to 20thDay
55%5%11%20%8%1
1758
21st to endDay
56%48%22%8%2
1480
March1st to 10thDay
51%5%10%23%10%1
1800
11th to 20thDay
51%413%21%10%1
1852
21st to endDay
59%5%10%19%6%1
2376
April1st to 10thDay
44%7%12%21%14%1
2160
11th to 20thDay
46%5%11%24%11%4
2134
21st to endDay
49%5%12%20%10%3
2209
May1st to 10thDay
49%6%15%21%8%
2340
11th to 20thDay
46%7%13%19%13%1
2313
21st to endDay
40%10%14%19%14%3
2725
June1st to 10thDay
34%8%13%26%16%3
2520
11th to 20thDay
33%8%12%23%20%5%
2520
21st to endDay
36%8%16%21%15%4
2520
July1st to 10thDay
34%8%15%26%14%3
2451
11th to 20thDay
31%10%16%26%16%2
2445
21st to endDay
30%8%18%26%16%2
2591
August1st to 10thDay
31%8%15%31%13%2
2302
11th to 20thDay
33%9%16%27%13%2
2125
21st to endDay
28%8%14%27%16%7%
2376
September1st to 10thDay
38%6%12%23%17%4
2160
11th to 20thDay
33%6%11%24%23%3
2034
21st to endDay
32%5%10%26%23%3
1980
October1st to 10thDay
34%6%13%26%19%3
1965
11th to 20thDay
41%49%22%22%2
1800
21st to endDay
47%49%24%14%1
1804
November1st to 10thDay
33%414%26%18%5%
1672
11th to 20thDay
44%49%23%15%4
1710
21st to endDay
48%5%9%22%14%1
1710
December1st to 10thDay
55%5%12%19%9%1
1577
11th to 20thDay
55%48%26%6%1
1915
21st to endDay
72%49%10%4
2783
January1st to 10thNight
52%5%8%21%13%1
2648
11th to 20thNight
59%310%19%8%
2617
21st to endNight
54%411%20%9%1
2651
February1st to 10thNight
57%412%17%8%2
2228
11th to 20thNight
49%411%21%11%2
2099
21st to endNight
52%410%21%10%3
1776
March1st to 10thNight
50%5%8%22%14%1
2160
11th to 20thNight
46%5%13%22%12%2
2121
21st to endNight
52%5%12%21%8%2
1980
April1st to 10thNight
41%7%10%25%16%2
1800
11th to 20thNight
42%5%9%23%17%4
1775
21st to endNight
49%6%9%20%12%3
1750
May1st to 10thNight
44%8%12%25%10%1
1620
11th to 20thNight
42%7%12%21%16%1
1580
21st to endNight
38%8%15%18%15%5%
1552
June1st to 10thNight
33%6%11%27%20%5%
1440
11th to 20thNight
30%7%11%26%22%4
1440
21st to endNight
31%7%16%22%19%5%
1440
July1st to 10thNight
31%8%15%26%15%5%
1400
11th to 20thNight
23%5%16%32%21%3
1392
21st to endNight
25%6%15%30%20%4
1487
August1st to 10thNight
27%9%15%29%19%2
1608
11th to 20thNight
32%8%12%27%19%2
1776
21st to endNight
24%7%13%27%21%7%
1980
September1st to 10thNight
32%6%10%27%19%7%
1800
11th to 20thNight
28%5%10%27%26%5%
1908
21st to endNight
29%8%9%25%25%4
1980
October1st to 10thNight
30%5%11%26%24%4
1992
11th to 20thNight
36%47%27%22%4
2160
21st to endNight
45%6%8%22%17%3
2551
November1st to 10thNight
33%6%9%26%21%5%
2406
11th to 20thNight
40%410%24%19%2
2470
21st to endNight
49%49%23%15%1
2470
December1st to 10thNight
52%5%11%20%11%1
2598
11th to 20thNight
51%411%21%12%
3281
21st to endNight
70%47%11%6%1
4884

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 10thDay
21%19%33%19%8%
270
11th to 20thDay
24%18%36%18%4
258
21st to endDay
19%17%38%21%5%
264
February1st to 10thDay
28%16%33%19%4
240
11th to 20thDay
23%22%33%17%32
240
21st to endDay
26%15%38%18%3
198
March1st to 10thDay
21%20%37%18%4
240
11th to 20thDay
27%16%36%16%4
266
21st to endDay
29%15%34%16%6%1
462
April1st to 10thDay
18%15%32%26%8%1
420
11th to 20thDay
20%17%27%20%14%2
412
21st to endDay
27%13%35%15%8%2
420
May1st to 10thDay
18%13%32%24%10%2
423
11th to 20thDay
21%6%26%27%15%4
455
21st to endDay
10%430%28%18%9%
679
June1st to 10thDay
10%5%23%32%23%7%
630
11th to 20thDay
10%323%34%22%7%
630
21st to endDay
10%7%28%29%20%7%
630
July1st to 10thDay
10%214%26%28%20%
621
11th to 20thDay
6%317%35%26%13%
618
21st to endDay
10%215%31%32%10%
684
August1st to 10thDay
7%213%30%35%13%
500
11th to 20thDay
12%316%29%27%13%
439
21st to endDay
5%213%31%34%15%
495
September1st to 10thDay
12%416%27%31%9%
450
11th to 20thDay
9%213%29%32%15%
450
21st to endDay
12%6%24%24%21%14%
450
October1st to 10thDay
13%326%29%21%7%
435
11th to 20thDay
16%15%37%21%11%
270
21st to endDay
28%15%32%20%4
297
November1st to 10thDay
10%13%31%27%15%4
270
11th to 20thDay
19%17%31%22%9%1
270
21st to endDay
21%12%35%24%6%1
270
December1st to 10thDay
15%17%40%19%7%2
270
11th to 20thDay
20%14%37%20%7%1
270
21st to endDay
26%19%34%15%6%
297
January1st to 10thNight
20%14%38%24%4
950
11th to 20thNight
23%16%35%22%4
935
21st to endNight
22%14%36%25%3
990
February1st to 10thNight
26%12%38%22%2
788
11th to 20thNight
19%16%37%25%3
703
21st to endNight
28%12%37%21%2
592
March1st to 10thNight
23%13%33%26%5%
720
11th to 20thNight
21%10%37%24%7%
707
21st to endNight
24%10%31%28%6%
594
April1st to 10thNight
18%12%34%30%6%
540
11th to 20thNight
21%11%32%26%11%
533
21st to endNight
22%9%36%25%7%1
540
May1st to 10thNight
18%7%33%33%9%
540
11th to 20thNight
17%5%28%33%16%1
531
21st to endNight
11%5%25%34%24%3
584
June1st to 10thNight
11%322%41%24%
540
11th to 20thNight
9%222%45%21%1
540
21st to endNight
8%224%40%25%1
540
July1st to 10thNight
10%112%32%39%6%
525
11th to 20thNight
5%315%43%30%4
522
21st to endNight
6%114%45%31%3
591
August1st to 10thNight
7%211%40%35%4
537
11th to 20thNight
7%113%41%35%4
534
21st to endNight
8%214%34%39%4
594
September1st to 10thNight
14%314%35%29%4
540
11th to 20thNight
7%314%39%32%4
648
21st to endNight
13%421%30%27%4
720
October1st to 10thNight
11%424%38%19%4
720
11th to 20thNight
19%12%28%28%12%1
720
21st to endNight
22%12%33%26%6%
792
November1st to 10thNight
12%9%39%28%12%
740
11th to 20thNight
18%13%32%29%8%1
760
21st to endNight
23%13%30%27%7%
760
December1st to 10thNight
23%10%38%24%5%1
888
11th to 20thNight
23%9%34%27%6%
950
21st to endNight
28%16%31%21%3
1045
Page generated at 2024-01-14 08:55:02. Version ac07

Copyright 2024 Attilla Danko


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