Wears Valley
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wears Valley clear sky chart from 2005-11-06 to 2024-02-20.

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
44%
24021
17%
79853
13%
23910
49%
23910
19%
54098

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
26%
756
15%
4043
11%
737
34%
737
9%
2805
January11th to 20thNight
21%
760
21%
3980
9%
740
30%
740
8%
2682
January21st to endNight
22%
832
13%
4470
9%
814
35%
814
10%
3089
February1st to 10thNight
30%
760
19%
2309
12%
760
38%
760
19%
1622
February11th to 20thNight
16%
742
14%
2214
6%
739
24%
739
14%
1646
February21st to endNight
20%
592
18%
1776
8%
592
28%
592
14%
1333
March1st to 10thNight
26%
720
19%
2086
10%
720
33%
720
19%
1448
March11th to 20thNight
27%
720
15%
1980
8%
720
32%
720
18%
1451
March21st to endNight
29%
792
14%
2178
7%
792
34%
792
19%
1572
April1st to 10thNight
33%
709
19%
1969
11%
709
40%
709
25%
1291
April11th to 20thNight
35%
533
23%
1741
13%
533
47%
533
24%
1079
April21st to endNight
41%
540
22%
1620
12%
540
48%
540
25%
1060
May1st to 10thNight
43%
540
15%
1620
8%
540
48%
540
21%
1108
May11th to 20thNight
51%
531
13%
1593
9%
531
53%
531
20%
1128
May21st to endNight
61%
582
14%
1744
10%
582
63%
582
23%
1194
June1st to 10thNight
62%
540
13%
1620
11%
540
63%
540
22%
1104
June11th to 20thNight
71%
540
12%
1620
10%
540
72%
540
29%
1046
June21st to endNight
65%
540
15%
1620
13%
540
67%
540
25%
1073
July1st to 10thNight
68%
525
10%
1575
9%
525
68%
525
20%
1129
July11th to 20thNight
69%
522
10%
1566
9%
522
69%
522
24%
1064
July21st to endNight
69%
591
11%
1672
10%
558
70%
558
22%
1158
August1st to 10thNight
72%
537
13%
1600
13%
534
72%
534
25%
1087
August11th to 20thNight
65%
534
14%
1614
14%
534
65%
534
20%
1139
August21st to endNight
66%
594
14%
1980
15%
594
66%
594
20%
1339
September1st to 10thNight
64%
706
18%
1966
16%
706
64%
706
26%
1320
September11th to 20thNight
60%
720
18%
1980
17%
720
61%
720
26%
1362
September21st to endNight
56%
720
24%
1980
18%
720
61%
720
30%
1275
October1st to 10thNight
54%
720
26%
1980
23%
720
57%
720
34%
1215
October11th to 20thNight
44%
720
24%
2132
19%
720
51%
720
27%
1345
October21st to endNight
47%
792
28%
2376
24%
792
55%
792
30%
1440
November1st to 10thNight
51%
740
25%
2390
23%
740
57%
740
28%
1428
November11th to 20thNight
41%
760
24%
2470
19%
760
50%
760
26%
1529
November21st to endNight
41%
760
23%
2470
18%
760
49%
760
23%
1564
December1st to 10thNight
28%
760
16%
2470
11%
760
35%
760
15%
1813
December11th to 20thNight
33%
759
19%
2986
14%
759
42%
759
15%
2057
December21st to endNight
29%
832
10%
4463
10%
817
37%
817
8%
3103

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
13%8%46%6%45%5%6%7%36%
78746
Night
13%9%46%5%35%5%5%7%38%
80453
TransparencyDay
47%8%11%17%14%3
78469
Night
45%8%11%17%15%3
80249
SeeingDay
19%13%24%23%15%6%
13886
Night
18%11%21%29%18%3
24036

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
12%11%7%9%7%345%7%6%29%
2836
11th to 20thDay
13%13%6%9%6%46%445%31%
2840
21st to endDay
16%14%6%7%5%2445%6%32%
3124
February1st to 10thDay
15%12%5%7%6%35%45%5%32%
1866
11th to 20thDay
18%11%5%11%5%34446%31%
1838
21st to endDay
18%10%46%6%3345%5%34%
1480
March1st to 10thDay
13%10%46%5%345%5%7%38%
1872
11th to 20thDay
17%11%48%6%345%5%6%33%
1980
21st to endDay
14%12%47%6%345%5%6%34%
2178
April1st to 10thDay
10%7%35%6%46%47%7%41%
2006
11th to 20thDay
14%7%35%5%345%5%7%42%
2166
21st to endDay
15%5%36%6%45%45%6%40%
2340
May1st to 10thDay
13%7%35%6%45%6%6%7%38%
2340
11th to 20thDay
15%6%38%7%46%6%6%7%32%
2301
21st to endDay
12%7%37%6%47%7%7%9%32%
2531
June1st to 10thDay
10%6%36%7%5%7%7%7%9%33%
2340
11th to 20thDay
6%5%37%8%46%7%9%10%34%
2340
21st to endDay
9%6%36%7%5%6%7%7%10%34%
2340
July1st to 10thDay
11%6%37%9%5%7%8%8%11%26%
2340
11th to 20thDay
12%7%47%7%5%7%8%7%10%28%
2340
21st to endDay
11%6%36%8%6%8%7%8%9%27%
2547
August1st to 10thDay
11%6%37%7%5%7%7%8%11%28%
2327
11th to 20thDay
10%7%38%7%5%8%7%7%9%28%
2284
21st to endDay
12%7%37%7%5%7%6%8%8%30%
2370
September1st to 10thDay
13%5%36%6%36%6%7%8%37%
1980
11th to 20thDay
15%7%26%6%5%5%5%6%8%35%
1980
21st to endDay
14%5%25%5%446%6%6%42%
1980
October1st to 10thDay
12%5%245%35%45%5%51%
1980
11th to 20thDay
14%7%24423446%51%
1827
21st to endDay
14%6%3442445%5%49%
1980
November1st to 10thDay
11%7%15%423347%53%
1686
11th to 20thDay
10%9%35%5%345%6%5%46%
1710
21st to endDay
11%9%37%5%3345%6%43%
1710
December1st to 10thDay
16%12%47%5%35%5%5%6%33%
1710
11th to 20thDay
12%12%46%6%345%5%7%35%
2153
21st to endDay
11%12%6%7%7%445%46%34%
3124
January1st to 10thNight
14%16%6%9%5%34435%30%
4109
11th to 20thNight
17%11%47%6%4445%5%33%
4120
21st to endNight
16%13%47%6%3444434%
4532
February1st to 10thNight
14%11%47%4345%6%6%35%
2309
11th to 20thNight
18%12%5%8%6%3443432%
2213
21st to endNight
19%12%37%6%35%46%6%31%
1776
March1st to 10thNight
13%12%5%7%5%34446%38%
2086
11th to 20thNight
15%10%47%6%36%446%33%
1980
21st to endNight
14%9%46%6%35%5%5%6%35%
2178
April1st to 10thNight
14%8%3443446%7%45%
1969
11th to 20thNight
13%8%35%5%2445%7%44%
1741
21st to endNight
15%5%25%6%25%5%5%7%43%
1620
May1st to 10thNight
12%6%36%6%36%5%5%9%39%
1620
11th to 20thNight
15%6%36%5%36%7%6%9%36%
1592
21st to endNight
9%7%25%6%46%6%6%11%37%
1744
June1st to 10thNight
8%5%25%6%46%8%8%11%37%
1620
11th to 20thNight
44245%45%7%10%13%42%
1620
21st to endNight
7%6%35%6%46%6%7%11%40%
1620
July1st to 10thNight
10%6%46%5%5%7%8%7%9%33%
1620
11th to 20thNight
7%5%26%6%35%6%9%12%37%
1620
21st to endNight
7%5%36%6%48%7%9%12%34%
1771
August1st to 10thNight
8%6%25%5%45%7%7%9%40%
1611
11th to 20thNight
10%7%26%6%5%6%6%8%9%36%
1614
21st to endNight
10%6%36%6%45%6%7%10%37%
1980
September1st to 10thNight
11%5%26%5%46%46%7%42%
1966
11th to 20thNight
14%7%35%6%35%5%5%7%42%
1980
21st to endNight
11%6%36%435%5%5%6%48%
1980
October1st to 10thNight
15%6%24413346%53%
1980
11th to 20thNight
16%6%24424445%49%
2132
21st to endNight
13%6%2442445%7%49%
2376
November1st to 10thNight
13%6%35%423345%51%
2390
11th to 20thNight
13%9%35%42345%6%46%
2470
21st to endNight
13%9%35%4245%5%6%44%
2470
December1st to 10thNight
15%13%5%8%6%3445%6%31%
2470
11th to 20thNight
15%12%5%9%5%23445%36%
3042
21st to endNight
12%13%6%7%6%45%5%7%7%27%
4532

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
48%10%7%14%17%4
2837
11th to 20thDay
52%9%6%12%18%3
2840
21st to endDay
51%7%7%16%17%2
3124
February1st to 10thDay
53%6%8%15%16%3
1866
11th to 20thDay
54%6%7%16%14%3
1848
21st to endDay
52%410%12%16%6%
1480
March1st to 10thDay
46%6%8%17%17%6%
1872
11th to 20thDay
51%8%10%14%14%3
1980
21st to endDay
52%6%11%18%12%1
2178
April1st to 10thDay
41%7%11%22%16%2
2006
11th to 20thDay
43%6%9%17%21%4
2166
21st to endDay
46%6%10%24%13%2
2340
May1st to 10thDay
45%8%12%21%11%3
2340
11th to 20thDay
51%9%12%17%10%1
2305
21st to endDay
45%12%13%19%11%1
2531
June1st to 10thDay
46%11%15%18%8%1
2340
11th to 20thDay
44%11%18%15%10%2
2340
21st to endDay
44%11%15%17%10%3
2340
July1st to 10thDay
50%14%14%15%7%
2275
11th to 20thDay
50%11%16%12%9%2
2271
21st to endDay
49%14%15%16%6%
2405
August1st to 10thDay
49%13%17%16%5%
2314
11th to 20thDay
52%11%14%14%9%1
2284
21st to endDay
51%10%14%14%8%2
2370
September1st to 10thDay
45%8%13%17%14%3
1980
11th to 20thDay
47%9%10%18%15%1
1980
21st to endDay
41%8%11%19%16%5%
1980
October1st to 10thDay
36%6%11%21%21%5%
1980
11th to 20thDay
35%6%9%22%22%7%
1827
21st to endDay
35%5%8%23%22%6%
1980
November1st to 10thDay
34%48%19%28%7%
1686
11th to 20thDay
39%5%7%21%23%6%
1710
21st to endDay
41%6%7%20%21%5%
1710
December1st to 10thDay
52%8%7%17%13%3
1710
11th to 20thDay
44%9%10%14%19%4
2150
21st to endDay
49%8%9%21%12%1
3124
January1st to 10thNight
51%9%7%14%15%4
4109
11th to 20thNight
50%9%6%11%19%5%
4120
21st to endNight
55%5%7%11%19%3
4532
February1st to 10thNight
50%5%9%16%16%3
2309
11th to 20thNight
56%5%7%15%13%4
2214
21st to endNight
56%6%8%13%13%4
1776
March1st to 10thNight
49%48%14%19%5%
2086
11th to 20thNight
52%6%11%17%12%2
1980
21st to endNight
50%7%11%19%12%1
2178
April1st to 10thNight
41%5%12%22%18%2
1969
11th to 20thNight
40%5%10%20%20%5%
1741
21st to endNight
41%7%12%27%12%1
1620
May1st to 10thNight
44%9%14%22%10%2
1620
11th to 20thNight
44%12%16%19%9%1
1593
21st to endNight
40%12%16%23%8%1
1745
June1st to 10thNight
40%13%18%20%9%1
1620
11th to 20thNight
31%14%22%23%8%1
1620
21st to endNight
39%10%17%20%10%3
1620
July1st to 10thNight
44%13%17%17%9%
1575
11th to 20thNight
37%14%24%14%8%3
1566
21st to endNight
39%14%21%18%7%
1672
August1st to 10thNight
38%12%22%20%7%
1600
11th to 20thNight
43%14%16%17%10%1
1614
21st to endNight
41%12%19%18%8%1
1980
September1st to 10thNight
40%10%16%19%13%3
1966
11th to 20thNight
41%10%14%18%17%
1980
21st to endNight
38%7%12%21%19%3
1980
October1st to 10thNight
34%6%11%20%24%5%
1980
11th to 20thNight
39%5%9%22%19%5%
2132
21st to endNight
35%5%7%22%23%7%
2376
November1st to 10thNight
37%5%7%20%24%6%
2390
11th to 20thNight
39%5%7%19%22%7%
2470
21st to endNight
41%6%7%22%19%4
2470
December1st to 10thNight
55%7%9%14%12%4
2470
11th to 20thNight
48%8%7%13%20%4
3044
21st to endNight
52%9%10%15%11%1
4532

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
27%30%30%13%1
270
11th to 20thDay
34%27%24%13%1
270
21st to endDay
24%31%33%10%2
297
February1st to 10thDay
28%23%36%11%1
270
11th to 20thDay
39%32%24%5%
267
21st to endDay
37%32%24%7%1
198
March1st to 10thDay
26%21%33%16%4
312
11th to 20thDay
27%24%31%13%41
420
21st to endDay
25%21%30%19%5%
462
April1st to 10thDay
24%19%26%22%9%1
420
11th to 20thDay
21%22%26%19%9%3
412
21st to endDay
25%15%26%20%11%3
420
May1st to 10thDay
20%20%27%20%8%5%
423
11th to 20thDay
15%10%27%27%14%8%
447
21st to endDay
16%7%23%26%16%12%
485
June1st to 10thDay
12%7%24%30%18%8%
450
11th to 20thDay
8%5%21%30%23%12%
450
21st to endDay
13%6%26%27%17%12%
450
July1st to 10thDay
13%6%16%26%27%14%
445
11th to 20thDay
12%5%17%27%24%16%
444
21st to endDay
11%216%29%29%14%
488
August1st to 10thDay
15%7%17%25%22%14%
446
11th to 20thDay
11%5%17%32%26%10%
439
21st to endDay
13%314%26%30%14%
495
September1st to 10thDay
10%413%30%32%10%
450
11th to 20thDay
16%6%12%27%28%10%
450
21st to endDay
16%8%16%34%22%5%
450
October1st to 10thDay
15%7%25%26%20%7%
450
11th to 20thDay
18%11%26%26%16%2
450
21st to endDay
21%11%26%27%13%2
495
November1st to 10thDay
18%17%29%26%10%1
284
11th to 20thDay
19%21%34%23%4
270
21st to endDay
18%19%33%25%5%
270
December1st to 10thDay
28%22%34%14%1
270
11th to 20thDay
24%19%33%20%3
270
21st to endDay
25%20%39%12%4
297
January1st to 10thNight
23%19%28%25%5%
760
11th to 20thNight
25%21%29%21%5%
760
21st to endNight
21%20%33%24%2
836
February1st to 10thNight
22%15%30%30%3
760
11th to 20thNight
28%19%34%18%1
742
21st to endNight
29%21%28%20%2
592
March1st to 10thNight
21%18%30%26%4
720
11th to 20thNight
22%18%29%24%6%1
720
21st to endNight
22%15%30%24%9%1
792
April1st to 10thNight
21%16%27%26%10%1
709
11th to 20thNight
20%12%29%24%13%1
533
21st to endNight
18%10%26%32%14%1
540
May1st to 10thNight
16%11%25%33%13%2
540
11th to 20thNight
16%7%20%33%22%3
531
21st to endNight
12%314%33%32%5%
584
June1st to 10thNight
9%415%36%31%4
540
11th to 20thNight
5%314%34%35%9%
540
21st to endNight
8%314%35%35%6%
540
July1st to 10thNight
12%26%30%45%6%
525
11th to 20thNight
10%28%29%40%12%
522
21st to endNight
7%39%29%44%9%
591
August1st to 10thNight
10%36%32%40%8%
537
11th to 20thNight
11%37%34%39%5%
534
21st to endNight
11%38%28%40%10%
594
September1st to 10thNight
11%49%30%38%8%
706
11th to 20thNight
17%310%32%32%6%
720
21st to endNight
14%418%33%30%2
720
October1st to 10thNight
17%6%17%23%29%8%
720
11th to 20thNight
19%8%23%29%18%2
720
21st to endNight
17%10%22%34%14%2
792
November1st to 10thNight
18%8%19%34%18%3
740
11th to 20thNight
17%16%23%32%11%1
760
21st to endNight
20%11%24%32%13%1
760
December1st to 10thNight
23%17%26%27%6%
760
11th to 20thNight
20%16%26%30%7%1
760
21st to endNight
24%17%27%29%4
836
Page generated at 2024-02-17 06:28:42. Version ac07

Copyright 2024 Attilla Danko


Wears Valley Clear Sky Chart |Charts Home