Wawa
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Wawa clear sky chart from 2005-11-05 to 2017-11-30.

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%
15828
10%
47749
6%
15783
34%
15783
15%
35917

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%
900
7%
2595
4%
895
22%
895
9%
2179
January16th to endNight
22%
960
9%
2688
4%
960
27%
960
11%
2215
February1st to 15thNight
23%
798
9%
2379
4%
795
28%
795
13%
1844
February16th to endNight
22%
631
11%
1903
6%
631
26%
631
11%
1501
March1st to 15thNight
28%
720
15%
2127
8%
720
34%
720
19%
1481
March16th to endNight
31%
737
18%
2081
9%
737
39%
737
21%
1470
April1st to 15thNight
31%
539
12%
1747
8%
539
35%
539
16%
1230
April16th to endNight
32%
540
16%
1620
8%
540
40%
540
23%
1103
May1st to 15thNight
35%
540
10%
1557
8%
540
38%
540
17%
1148
May16th to endNight
38%
409
12%
1345
8%
408
43%
408
20%
915
June1st to 15thNight
42%
360
7%
1260
6%
360
44%
360
18%
860
June16th to endNight
44%
360
5%
1260
4%
360
46%
360
18%
856
July1st to 15thNight
49%
340
9%
1190
7%
340
51%
340
26%
729
July16th to endNight
49%
564
11%
1417
8%
531
48%
531
27%
954
August1st to 15thNight
57%
539
13%
1509
11%
536
59%
536
30%
983
August16th to endNight
44%
573
16%
1719
10%
573
49%
573
26%
1109
September1st to 15thNight
44%
606
12%
1866
8%
606
48%
606
22%
1257
September16th to endNight
36%
717
14%
1980
9%
717
39%
717
23%
1389
October1st to 15thNight
30%
720
13%
2088
8%
720
36%
720
18%
1536
October16th to endNight
24%
768
8%
2496
6%
768
27%
768
9%
2031
November1st to 15thNight
20%
760
10%
2507
6%
760
25%
760
10%
2017
November16th to endNight
17%
887
8%
2835
5%
887
21%
887
7%
2383
December1st to 15thNight
18%
900
5%
2700
2%
900
21%
900
8%
2273
December16th to endNight
19%
960
7%
2880
3%
960
22%
960
7%
2454

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
17%10%47%6%3445%6%28%
48673
Night
16%12%47%6%3445%6%27%
47909
Cloud CoverDay
18%11%46%5%3445%6%29%
48682
Night
16%12%47%6%3445%6%27%
47914
TransparencyDay
54%6%13%17%6%
48349
Night
55%6%12%17%6%
47751
SeeingDay
23%12%30%21%10%3
6290
Night
22%10%29%26%10%1
15828

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
13%21%7%10%7%445%36%14%
1342
16th to endDay
11%18%7%9%7%35%45%6%20%
1536
February1st to 15thDay
8%15%6%9%6%46%5%5%7%24%
1480
16th to endDay
8%16%7%10%10%5%6%5%45%19%
1569
March1st to 15thDay
14%11%48%6%35%446%31%
1823
16th to endDay
12%9%47%7%35%447%32%
2154
April1st to 15thDay
19%10%47%5%35%445%28%
2200
16th to endDay
19%9%36%5%24445%34%
2340
May1st to 15thDay
18%7%27%6%35%446%32%
2391
16th to endDay
19%7%35%5%345%5%7%32%
2770
June1st to 15thDay
17%8%35%6%25%45%7%32%
2700
16th to endDay
19%6%25%4345%5%7%33%
2700
July1st to 15thDay
16%6%345%35%5%5%8%36%
2698
16th to endDay
15%7%25%425%5%6%7%36%
2655
August1st to 15thDay
14%7%26%6%345%5%8%34%
2442
16th to endDay
19%6%35%42445%8%36%
2482
September1st to 15thDay
19%7%25%4335%5%7%35%
2082
16th to endDay
24%7%35%5%2345%6%31%
1980
October1st to 15thDay
21%12%36%5%24346%29%
1869
16th to endDay
25%15%5%8%7%35%34415%
1728
November1st to 15thDay
21%16%6%8%6%33436%18%
1681
16th to endDay
19%18%7%8%7%445%5%5%14%
1447
December1st to 15thDay
13%17%8%11%8%36%5%5%6%12%
1260
16th to endDay
17%20%8%10%5%34445%14%
1344
January1st to 15thNight
16%16%7%12%8%3445%6%13%
2595
16th to endNight
12%19%7%10%8%35%45%6%16%
2688
February1st to 15thNight
8%14%6%10%7%46%5%5%7%22%
2379
16th to endNight
11%15%7%11%7%35%5%45%21%
1903
March1st to 15thNight
12%10%46%5%34447%36%
2114
16th to endNight
10%10%36%6%36%46%5%36%
2081
April1st to 15thNight
17%9%36%5%35%5%6%6%30%
1747
16th to endNight
17%9%36%413446%38%
1620
May1st to 15thNight
16%8%47%6%45%5%5%6%29%
1557
16th to endNight
20%8%34324346%37%
1343
June1st to 15thNight
18%8%36%44444436%
1260
16th to endNight
18%5%36%5%35%5%5%8%33%
1260
July1st to 15thNight
13%5%25%5%245%6%9%39%
1260
16th to endNight
15%4345%3446%8%38%
1513
August1st to 15thNight
11%6%25%43345%9%41%
1518
16th to endNight
14%5%25%43445%8%42%
1719
September1st to 15thNight
13%8%245%35%45%6%39%
1866
16th to endNight
21%6%235%2335%7%38%
1980
October1st to 15thNight
20%9%26%43445%5%32%
2088
16th to endNight
24%13%47%7%3335%6%20%
2496
November1st to 15thNight
22%14%5%8%5%34435%22%
2507
16th to endNight
20%15%6%10%7%45%44417%
2835
December1st to 15thNight
13%19%7%8%6%36%5%6%6%16%
2700
16th to endNight
17%20%6%10%6%35%45%5%14%
2880

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
13%21%6%11%7%35%445%14%
1342
16th to endDay
11%18%7%10%7%35%46%5%20%
1536
February1st to 15thDay
8%16%5%9%7%36%5%46%24%
1480
16th to endDay
8%15%7%11%9%5%5%445%19%
1569
March1st to 15thDay
15%11%49%6%25%445%31%
1833
16th to endDay
13%9%5%7%6%35%346%33%
2153
April1st to 15thDay
19%11%5%6%6%25%435%28%
2200
16th to endDay
19%10%36%5%24445%34%
2340
May1st to 15thDay
19%6%46%6%34446%32%
2391
16th to endDay
20%8%25%5%3445%7%32%
2770
June1st to 15thDay
19%8%25%5%35%5%5%7%32%
2700
16th to endDay
20%7%25%43445%7%33%
2700
July1st to 15thDay
18%6%2443445%7%37%
2698
16th to endDay
17%7%244246%6%8%36%
2655
August1st to 15thDay
17%6%35%5%35%5%5%7%34%
2442
16th to endDay
20%6%35%424447%36%
2482
September1st to 15thDay
21%7%25%42435%7%35%
2082
16th to endDay
25%6%345%2345%7%31%
1980
October1st to 15thDay
21%13%35%5%23347%29%
1869
16th to endDay
26%17%5%8%5%3434316%
1728
November1st to 15thDay
22%17%7%7%6%23435%18%
1681
16th to endDay
19%19%6%8%7%44445%14%
1447
December1st to 15thDay
13%17%8%12%8%45%6%5%5%12%
1260
16th to endDay
17%19%9%10%5%4444415%
1344
January1st to 15thNight
17%16%7%13%7%3445%5%15%
2595
16th to endNight
12%18%8%10%8%3445%6%16%
2688
February1st to 15thNight
8%14%6%10%7%46%5%5%7%22%
2372
16th to endNight
11%16%6%11%7%36%445%21%
1903
March1st to 15thNight
12%10%46%5%34447%35%
2127
16th to endNight
10%10%36%5%35%45%6%36%
2081
April1st to 15thNight
18%9%36%6%25%5%5%6%30%
1747
16th to endNight
16%10%36%423346%38%
1620
May1st to 15thNight
16%8%47%6%35%5%5%6%29%
1556
16th to endNight
20%7%33424446%37%
1343
June1st to 15thNight
19%7%37%335%34436%
1260
16th to endNight
18%5%36%5%35%45%8%34%
1260
July1st to 15thNight
13%5%245%245%6%9%40%
1260
16th to endNight
15%5%244345%6%7%40%
1513
August1st to 15thNight
12%7%2442446%9%41%
1518
16th to endNight
14%5%2443435%7%42%
1719
September1st to 15thNight
14%8%344345%5%6%40%
1866
16th to endNight
22%6%24423346%38%
1980
October1st to 15thNight
20%9%35%5%35%45%5%32%
2088
16th to endNight
24%14%47%6%3335%6%20%
2496
November1st to 15thNight
21%14%5%7%6%24435%22%
2507
16th to endNight
20%15%6%10%7%35%5%3317%
2835
December1st to 15thNight
13%20%7%9%6%35%5%6%5%15%
2700
16th to endNight
16%21%7%10%6%35%445%14%
2880

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
69%5%10%10%2
1343
16th to endDay
63%5%8%13%8%
1536
February1st to 15thDay
57%6%13%13%7%
1482
16th to endDay
62%6%8%12%8%
1569
March1st to 15thDay
53%5%10%18%10%1
1833
16th to endDay
50%6%13%17%8%2
2154
April1st to 15thDay
56%6%10%16%9%
2200
16th to endDay
51%5%9%19%11%2
2340
May1st to 15thDay
53%5%11%18%8%2
2391
16th to endDay
50%7%13%20%7%
2774
June1st to 15thDay
50%6%12%16%11%1
2700
16th to endDay
48%6%14%21%7%
2700
July1st to 15thDay
42%8%17%23%7%
2539
16th to endDay
44%8%15%25%6%
2488
August1st to 15thDay
46%7%18%20%5%
2427
16th to endDay
46%7%17%21%6%
2482
September1st to 15thDay
48%7%18%19%6%
2082
16th to endDay
52%7%16%19%3
1980
October1st to 15thDay
55%5%17%17%3
1869
16th to endDay
70%7%9%9%3
1728
November1st to 15thDay
67%7%9%11%3
1681
16th to endDay
69%8%10%7%2
1447
December1st to 15thDay
68%9%11%8%3
1260
16th to endDay
70%5%10%9%3
1344
January1st to 15thNight
69%5%9%11%2
2595
16th to endNight
67%5%8%12%6%
2688
February1st to 15thNight
58%7%13%14%5%
2381
16th to endNight
63%5%10%14%6%
1903
March1st to 15thNight
48%5%14%18%12%
2127
16th to endNight
47%6%10%21%10%2
2081
April1st to 15thNight
52%5%11%19%10%1
1747
16th to endNight
47%411%20%13%2
1620
May1st to 15thNight
53%5%10%18%9%2
1557
16th to endNight
47%6%13%23%8%
1345
June1st to 15thNight
49%5%11%18%13%1
1260
16th to endNight
47%6%16%22%5%
1260
July1st to 15thNight
38%6%17%27%9%
1190
16th to endNight
41%6%15%26%9%
1417
August1st to 15thNight
38%6%22%24%7%
1509
16th to endNight
40%7%18%27%6%
1719
September1st to 15thNight
42%9%15%23%8%
1866
16th to endNight
45%7%15%25%5%
1980
October1st to 15thNight
50%8%16%18%5%
2088
16th to endNight
64%7%12%11%4
2496
November1st to 15thNight
63%7%12%12%3
2507
16th to endNight
70%6%9%9%3
2835
December1st to 15thNight
65%10%10%10%2
2700
16th to endNight
69%8%8%9%3
2880

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
26%10%33%17%12%
75
16th to endDay
29%5%22%31%9%2
96
February1st to 15thDay
31%12%36%15%31
90
16th to endDay
27%24%32%14%1
81
March1st to 15thDay
19%13%30%24%8%2
123
16th to endDay
20%13%28%25%10%2
288
April1st to 15thDay
22%10%34%22%8%1
270
16th to endDay
23%17%27%17%9%4
270
May1st to 15thDay
20%16%30%18%9%4
348
16th to endDay
25%13%31%19%7%2
517
June1st to 15thDay
22%12%34%19%6%3
495
16th to endDay
22%11%33%16%12%3
495
July1st to 15thDay
18%7%35%25%12%2
475
16th to endDay
17%9%31%27%7%6%
515
August1st to 15thDay
18%7%26%24%17%5%
415
16th to endDay
26%7%22%18%16%7%
332
September1st to 15thDay
21%7%24%23%18%4
315
16th to endDay
23%11%30%22%9%1
314
October1st to 15thDay
25%16%26%23%7%
291
16th to endDay
34%18%25%14%6%
144
November1st to 15thDay
27%21%32%15%3
127
16th to endDay
27%24%27%15%4
90
December1st to 15thDay
35%6%41%311%1
60
16th to endDay
39%10%37%10%1
64
January1st to 15thNight
23%14%33%21%6%
900
16th to endNight
21%11%33%25%6%1
960
February1st to 15thNight
15%9%40%26%7%
798
16th to endNight
18%12%34%24%8%
631
March1st to 15thNight
16%14%34%25%7%
720
16th to endNight
16%13%33%23%11%1
737
April1st to 15thNight
22%12%28%28%7%1
539
16th to endNight
21%9%32%23%10%2
540
May1st to 15thNight
21%9%27%30%8%2
540
16th to endNight
23%8%24%32%9%1
409
June1st to 15thNight
23%7%21%32%15%
360
16th to endNight
18%7%24%35%13%
360
July1st to 15thNight
14%327%40%13%
340
16th to endNight
16%325%35%17%1
564
August1st to 15thNight
15%5%15%38%23%2
539
16th to endNight
17%327%31%17%1
573
September1st to 15thNight
17%6%26%26%18%4
606
16th to endNight
25%6%27%27%11%1
717
October1st to 15thNight
25%11%27%26%9%
720
16th to endNight
31%12%23%23%7%1
768
November1st to 15thNight
28%14%30%20%6%
760
16th to endNight
29%12%30%19%7%
887
December1st to 15thNight
24%16%31%18%8%
900
16th to endNight
26%14%27%21%7%1
960
Page generated at 2017-12-01 12:13:47. Version ac04

Copyright 2017 A. Danko


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